KR20230094048A - Optical system and camera module including the same - Google Patents

Abstract

The optical system according to the embodiment includes first to third lenses disposed along an optical axis in a direction from the object side to the sensor side,
The optical system,
Satisfies 40 degree ≤ FOV ≤ 50 degree,
The object side surface and the sensor side surface of the first lens are spherical, and the first lens has a meniscus shape convex toward the object side,
The first lens, the second lens and the third lens,
Satisfy 1.7 ≤ nt_1 ≤ 2.3,
1.2mm ≤ D_1 ≤ 2.2mm
0.15 ≤ D_1/TTL ≤ 0.35
1.5 < D_1 / D_2 < 2.5
Satisfy 3.0 < D_1 / D_3 < 4.0,
It satisfies TTL ≤ 9mm.
(nt_1 is the refractive index of the first lens, TTL is the distance on the optical axis from the object side surface of the first lens to the top surface of the image sensor, D_1 is the thickness of the first lens on the optical axis, and FOV is the It means the angle of view (FOV) of the optical system.)

Description

Optical system and camera module including the same {OPTICAL SYSTEM AND CAMERA MODULE INCLUDING THE SAME}

The embodiment relates to an optical system having improved optical performance and a camera module including the same.

ADAS (Advanced Driving Assistance System) is an advanced driver assistance system for assisting the driver in driving. It senses the situation ahead, determines the situation based on the sensed result, and controls the vehicle behavior based on the situation judgment consists of For example, an ADAS sensor device detects a vehicle ahead and recognizes a lane. Then, when the target lane, target speed, and forward target are determined, the vehicle's Electrical Stability Control (ESC), EMS (Engine Management System), and MDPS (Motor Driven Power Steering) are controlled. Typically, ADAS can be implemented as an automatic parking system, a low-speed city driving assistance system, a blind spot warning system, and the like.

Sensor devices for detecting the situation ahead in ADAS include a GPS sensor, laser scanner, front radar, Lidar, and the like, and the most representative is a camera for photographing the front, rear, and side of the vehicle.

Such a camera may be placed outside or inside a vehicle to detect surrounding conditions of the vehicle. In addition, the camera may be disposed inside the vehicle to detect situations of the driver and passengers. For example, the camera may photograph the driver at a location adjacent to the driver, and detect the driver's health condition, drowsiness, or drinking. In addition, the camera can photograph the passenger at a location adjacent to the passenger, detect whether the passenger is sleeping, health status, etc., and provide information about the passenger to the driver.

In particular, the most important element to obtain an image from a camera is an imaging lens that forms an image. Recently, interest in high performance, such as high image quality and high resolution, is increasing, and in order to realize this, research on an optical system including a plurality of lenses is being conducted. However, there is a problem in that the characteristics of the optical system change when the camera is exposed to harsh environments outside or inside the vehicle, such as high temperature, low temperature, moisture, and high humidity. In this case, the camera has a problem in that it is difficult to uniformly derive excellent optical characteristics and aberration characteristics.

Therefore, a new optical system and camera capable of solving the above problems are required.

Embodiments are intended to provide an optical system and a camera module with improved optical characteristics.

In addition, embodiments are intended to provide an optical system and a camera module capable of providing excellent optical characteristics in a low or high temperature environment.

In addition, embodiments are intended to provide an optical system and a camera module capable of preventing or minimizing changes in optical characteristics in various temperature ranges.

The optical system according to the embodiment includes first to third lenses disposed along an optical axis in a direction from an object side to a sensor side,

The optical system,

Satisfies 40 degree ≤ FOV ≤ 50 degree,

The object side surface and the sensor side surface of the first lens are spherical, and the first lens has a meniscus shape convex toward the object side,

The first lens, the second lens and the third lens,

Satisfy 1.7 ≤ nt_1 ≤ 2.3,

1.2mm ≤ D_1 ≤ 2.2mm

0.15 ≤ D_1/TTL ≤ 0.35

1.5 < D_1 / D_2 < 2.5

Satisfy 3.0 < D_1 / D_3 < 4.0,

It satisfies TTL ≤ 9mm.

(nt_1 is the refractive index of the first lens, TTL is the distance on the optical axis from the object side surface of the first lens to the top surface of the image sensor, D_1 is the thickness of the first lens on the optical axis, and FOV is the It means the angle of view (FOV) of the optical system.)

The thickness of the first lens of the optical system according to the embodiment satisfies the following condition.

1.2mm ≤ D_1 ≤ 2.2mm

The optical system according to the embodiment further includes an infrared pass filter.

The optical system according to the embodiment further includes a diaphragm disposed between the first lens and the second lens, the diaphragm comprising:

It satisfies 0 < d1Ap < 0.2.

(d1Ap means the distance (mm) in the optical axis direction of the diaphragm from the tip of the effective mirror of the first lens.)

The first lens and the aperture of the optical system according to the embodiment,

Satisfies 0.8 < CA_L1S2 / CA_Ap < 1.8.

(CA_L1S2 means the size (mm) of the effective diameter of the sensor side of the first lens, and CA_Ap means the size (mm) of the effective diameter of the diaphragm.)

The first lens, the second lens, and the third lens of the optical system according to the embodiment,

0.3 < |f1 / f2| < 1.2

1 < |f3 / f1| satisfies < 10.

(f1 is the focal length of the first lens (mm), f2 is the focal length of the second lens (mm), and f3 is the focal length of the third lens (mm).)

The second lens of the optical system according to the embodiment,

1.0 < |L2R1| / |L2R2| < 2.0 is satisfied.

(L2R1 is the radius of curvature of the object-side surface of the second lens, and L2R2 is the radius of curvature of the sensor-side surface of the second lens.)

The third lens of the optical system according to the embodiment,

1.1 < |L3R1| / |L3R2| < 1.5 is satisfied.

(L3R1 is the radius of curvature of the object-side surface of the third lens, and L3R2 is the radius of curvature of the sensor-side surface of the third lens.)

The first lens and the second lens of the optical system according to the embodiment,

0.2 < d12 / D_1 < 0.9 is satisfied.

(d12 is the distance (mm) between the first lens and the second lens on the optical axis (OA), and D_1 is the thickness (mm) on the optical axis of the first lens.)

The first lens and the second lens of the optical system according to the embodiment have positive (+) refractive power, and the third lens has negative (-) refractive power.

An optical system according to an embodiment includes first to third lenses arranged along an optical axis in a direction from an object side to a sensor side, wherein the first lens and the second lens have positive refractive power, and the first lens and the second lens have positive (+) refractive power. 3 The lens has a negative (-) refractive power, the first lens has a meniscus shape convex toward the object, the first lens, the second lens, and the third lens,

1.2mm ≤ D_1 ≤ 2.2mm

0.15 ≤ D_1/TTL ≤ 0.35

1.5 < D_1 / D_2 < 2.5

Satisfy 3.0 < D_1 / D_3 < 4.0,

satisfies TTL ≤ 9 mm,

The optical system,

The change rate of the effective focal length at high temperature compared to room temperature is 0% to 10%,

The change rate of the angle of view at a high temperature compared to room temperature is 0% to 10%.

(Room temperature is 20 ° C to 30 ° C, high temperature is 80 ° C to 90 ° C.)

The first lens to the third lens of the optical system according to the embodiment,

dnt_1/dt ≥ 0;

dnt_2/dt < 0;

Satisfies dnt_3/dt < 0.

(dnt_1/dt is the change in refractive index of the first lens according to temperature change, dnt_2/dt is the change in refractive index of the second lens according to temperature change, and dnt_3/dt is the change in refractive index of the third lens according to temperature change .)

The first lens and the second lens of the optical system according to the embodiment,

|dnt_2/dt| / |dnt_1/dt| > satisfies 20

(|dnt_2/dt| is the refractive index change of the second lens in the d-line of 20 to 40 degrees, and |dnt_1/dt| is the refractive index change of the first lens in the d-line of 20 to 40 degrees.)

A sum of Abbe numbers of the first lens, the second lens, and the third lens of the optical system according to the embodiment is 50 or more and 70 or less.

An optical system and a camera module according to an embodiment may have improved optical characteristics. In detail, in the optical system according to the embodiment, a plurality of lenses may have a set shape, refractive power, focal length, thickness, etc. to have improved distortion characteristics and aberration characteristics. Accordingly, the optical system and the camera module according to the embodiment may provide high-resolution and high-quality images within a set angle of view range.

In addition, the optical system and the camera module according to the embodiment may operate in various temperature ranges. In detail, the optical system may include a first lens made of glass and second and third lenses made of plastic. In this case, each of the first to third lenses may have a set refractive power. Accordingly, even when the focal length of each lens changes due to a change in refractive index due to a change in temperature, the first to third lenses can compensate each other. That is, the optical system can effectively distribute the refractive power in the temperature range of low temperature (about -40 ℃) to high temperature (about 99 ℃), and in the temperature range of low temperature (-40 ℃) to high temperature (99 ℃). Changes in optical properties can be prevented or minimized. Therefore, the optical system and the camera module according to the embodiment may maintain improved optical characteristics in various temperature ranges.

In addition, the optical system and the camera module according to the embodiment may satisfy the minimum angle of view set by the lens and implement excellent optical characteristics. Due to this, the optical system can be provided with a slimmer and more compact structure. Accordingly, the optical system and the camera module can be provided for various applications and devices, and can have excellent optical properties even in harsh temperature environments, for example, inside a high-temperature vehicle in summer.

1 is a plan view of a vehicle to which a camera module or an optical system according to an embodiment is applied.
2 and 3 are views illustrating the interior of a vehicle to which a camera module or optical system according to an embodiment is applied.
4 is a table of refractive index data of a first lens for light of various wavelengths in various temperature ranges of an optical system according to an embodiment.
5 is a graph of a change in refractive index according to a change in temperature of a first lens in an optical system according to an embodiment.
6 is a table of refractive index data of a second lens and a third lens for light of various wavelengths in various temperature ranges of an optical system according to an embodiment.
7 is a graph of a change in refractive index according to a change in temperature of a second lens and a third lens in an optical system according to an embodiment.
8 is a configuration diagram of an optical system according to the first embodiment.
9 is a table of first to third lenses of the optical system according to the first embodiment.
10 is a table of sag values of the first lens of the optical system according to the first embodiment.
11 is a table of thicknesses of the first lens of the optical system according to the first embodiment.
12 is a table of sag values of the second lens of the optical system according to the first embodiment.
13 is a table of the thickness of the second lens of the optical system according to the first embodiment.
14 is a table of sag values of the third lens of the optical system according to the first embodiment.
15 is a table of thicknesses of the third lens of the optical system according to the first embodiment.
16 is a table of aspherical surface coefficients of the lens of the optical system according to the first embodiment.
17 and 18 are tables of intervals between lenses of the optical system according to the first embodiment.
19 is a graph of relative illumination for each field of the optical system according to the first embodiment.
20 is data on distortion characteristics of the optical system according to the first embodiment.
21 to 29 are graphs of diffraction MTF and aberration diagrams for each temperature of the optical system according to the first embodiment.
30 is a configuration diagram of an optical system according to the second embodiment.
31 is a table of first to third lenses of the optical system according to the second embodiment.
32 is a table of sag values of the first lens of the optical system according to the second embodiment.
33 is a table of thicknesses of the first lens of the optical system according to the second embodiment.
34 is a table of sag values of the second lens of the optical system according to the second embodiment.
35 is a table of thicknesses of the second lens of the optical system according to the second embodiment.
36 is a table of sag values of the third lens of the optical system according to the second embodiment.
37 is a table of thicknesses of the third lens of the optical system according to the second embodiment.
38 is a table of aspherical surface coefficients of the lens of the optical system according to the second embodiment.
39 and 40 are tables of intervals between lenses of the optical system according to the second embodiment.
41 is a graph of relative illumination for each field of the optical system according to the second embodiment.
42 is data on distortion characteristics of the optical system according to the second embodiment.
43 to 51 are graphs of diffraction MTF and aberration diagrams for each temperature of the optical system according to the second embodiment.
52 is a configuration diagram of an optical system according to a third embodiment.
53 is a table of first to third lenses of the optical system according to the third embodiment.
54 is a table of sag values of the first lens of the optical system according to the third embodiment.
55 is a table of thicknesses of the first lens of the optical system according to the third embodiment.
56 is a table of sag values of the second lens of the optical system according to the third embodiment.
57 is a table of thicknesses of the second lens of the optical system according to the third embodiment.
58 is a table of sag values of the third lens of the optical system according to the third embodiment.
59 is a table of thicknesses of the third lens of the optical system according to the third embodiment.
60 is a table of aspherical surface coefficients of the lens of the optical system according to the third embodiment.
61 and 62 are tables of intervals between lenses of the optical system according to the third embodiment.
63 is a graph of relative illumination for each field of the optical system according to the third embodiment.
64 is data on distortion characteristics of the optical system according to the third embodiment.
65 to 73 are graphs of diffraction MTF and aberration diagrams for each temperature of the optical system according to the third embodiment.
74 is a configuration diagram for explaining some terms in an optical system according to an embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, the technical idea of the present invention is not limited to some of the described embodiments, but may be implemented in a variety of different forms, and if it is within the scope of the technical idea of the present invention, one or more of the components among the embodiments can be selectively selected. can be used by combining and substituting.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention, unless explicitly specifically defined and described, can be generally understood by those of ordinary skill in the art to which the present invention belongs. It can be interpreted as meaning, and commonly used terms, such as terms defined in a dictionary, can be interpreted in consideration of contextual meanings of related technologies.

Also, terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention. In this specification, the singular form may also include the plural form unless otherwise specified in the phrase, and when described as "at least one (or more than one) of A and (and) B and C", A, B, and C are combined. may include one or more of all possible combinations.

Also, terms such as first, second, A, B, (a), and (b) may be used to describe components of an embodiment of the present invention. These terms are only used to distinguish the component from other components, and the term is not limited to the nature, order, or order of the corresponding component. And, when a component is described as being 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected to, combined with, or connected to the other component, but also with the component. It may also include the case of being 'connected', 'combined', or 'connected' due to another component between the other components.

In addition, when it is described as being formed or disposed on the "top (above) or bottom (bottom)" of each component, the top (top) or bottom (bottom) is not only a case where two components are in direct contact with each other, but also one A case in which another component above is formed or disposed between two components is also included. In addition, when expressed as "up (up) or down (down)", it may include the meaning of not only the upward direction but also the downward direction based on one component.

Also, the convex surface of the lens may mean that the lens surface in the optical axis area has a convex shape, and the concave surface of the lens may mean that the lens surface in the optical axis area has a concave shape.

Also, the “object-side surface” may refer to a surface of a lens facing the object side based on an optical axis, and the “sensor-side surface” may refer to a surface of a lens facing the image sensor based on an optical axis.

In addition, the vertical direction may mean a direction perpendicular to the optical axis, and the end of the lens or lens surface may mean the most end of an effective area of the lens through which incident light passes.

In addition, the center thickness of the lens may refer to a length between the object side and the sensor side of the lens in the optical axis direction.

In addition, the size of the effective mirror of the lens surface may have a measurement error of up to ±0.4 mm depending on the measurement method.

For example, the effective diameter may be 2 mm or less, or 1 mm or less, or 0.3 mm or less with respect to the inner diameter of the flange portion.

In addition, in the embodiment, low temperature may mean a specific temperature (-40 ° C) or a temperature range of about -40 ° C to about 30 ° C, and room temperature means a specific temperature (22 ° C) or about 20 ° C to about 30 ° C. It may mean a temperature range of 30 ° C. Also, high temperature may mean a specific temperature (90°C) or a temperature range of about 85°C to about 105°C.

1 is a plan view of a vehicle to which a camera module or optical system according to an embodiment is applied, and FIGS. 2 and 3 are views showing the interior of a vehicle to which a camera module or optical system according to an embodiment is applied.

First, referring to FIG. 1 , a vehicle camera system according to an embodiment includes an image generator 2110, a first information generator 2120, and a second information generator 2210, 2220, 2230, 2240, 2250, and 2260. and a controller 2140.

The image generator 2110 may include at least one first camera module 2310 disposed outside or inside the vehicle 2000, and may generate a front image of the vehicle 2000. In addition, the image generator 2110 captures not only the front of the vehicle 2000 but also the surroundings of the vehicle 2000 in one or more directions using the first camera module 2310 to obtain an image of the surroundings of the vehicle 2000. can create Here, the front image and the surrounding image may be digital images, and may include color images, black and white images, and infrared images. Also, the front image and the surrounding image may include a still image and a moving image. The image generator 2110 may provide the front image and the surrounding image to the controller 2140 .

Subsequently, the first information generator 2120 may include at least one radar or/and camera disposed in the vehicle 2000, and detects a front of the vehicle 2000 to generate first detection information. Specifically, the first information generating unit 2120 is disposed in the vehicle 2000 and detects the location and speed of the vehicles 2000 located in front of the vehicle 2000, presence and location of pedestrians, etc. can create

The distance between the vehicle 2000 and the vehicle in front can be controlled to be kept constant using the first detection information generated by the first information generating unit 2120, and the driver can change the driving lane of the vehicle 2000. Driving stability of the vehicle 2000 may be increased in a predetermined specific case, such as when parking in reverse or in reverse parking. The first information generator 2120 may provide the first detection information to the controller 2140 .

Next, the second information generators 2210, 2220, 2230, 2240, 2250, and 2260 are based on the front image generated by the image generator 2110 and the first detection information generated by the first information generator 2120. Thus, each side of the vehicle 2000 is sensed to generate second sensing information. Specifically, the second information generators 2210, 2220, 2230, 2240, 2250, and 2260 may include at least one radar or/and camera disposed in the vehicle 2000, and may be located on the side of the vehicle 2000. It can detect the position and speed of the located vehicles or take an image. Here, the second information generators 2210 , 2220 , 2230 , 2240 , 2250 , and 2260 may be disposed at both front corners, side mirrors, and rear center and rear corners of the vehicle 2000 , respectively.

Also, referring to FIGS. 2 and 3 , the image generator 2110 may include at least one second camera module 2320 disposed inside the vehicle 2000 . The second camera module 2320 may be disposed adjacent to the driver and passenger. For example, the second camera module 2320 may be disposed at a location spaced apart from the driver and passengers by a first distance d1 to generate an internal image of the vehicle 2000 . In this case, the first distance d1 may be about 500 mm or more. In detail, the first distance d1 may be about 600 mm or more. Also, the second camera module 2320 may have an angle of view (FOV) of about 55 degrees or greater.

The image generator 2110 may generate an internal image of the vehicle 2000 by capturing a driver and/or a passenger inside the vehicle 2000 using the second camera module 2320 . Here, the interior image of the vehicle may be a digital image, and may include a color image, a black and white image, and an infrared image. Also, the internal image may include a still image and a moving image. The image generator 2110 provides the inside image of the vehicle 2000 to the controller 2140 .

The controller 2140 may provide information to the occupants of the vehicle 2000 based on information provided from the image generator 2110 . For example, based on the information provided from the image generator 2110, the driver's health status, drowsiness, alcohol consumption, etc. may be detected, and corresponding information such as guidance and warning may be provided to the driver. there is. In addition, based on the information provided from the image generator 2110, it is possible to detect whether or not the passenger is sleeping or not, and to provide information to the driver and/or the passenger.

Such a camera system for a vehicle may include a camera module having an optical system 1000 according to the following embodiment, and provides the information to the user using information obtained through the front, rear, each side, or corner area of the vehicle 2000. It is possible to protect the vehicle 2000 and objects from autonomous driving or surrounding safety by processing the vehicle 2000 . Also, it may be disposed inside the vehicle 2000 to provide various information to the driver and passengers. That is, at least one of the first camera module 2310 and the second camera module 2320 may include an optical system 1000 to be described later.

A plurality of optical systems of the camera module according to the embodiment may be mounted in a vehicle in order to regulate safety, enhance self-driving functions, and increase convenience. In addition, the optical system of the camera module is applied to a vehicle as a component for controlling a lane keeping assistance system (LKAS), a lane departure warning system (LDWS), and a driver monitoring system (DMS). Such a camera module for a vehicle can realize stable optical performance even when the ambient temperature changes and provides a module with a competitive price, thereby securing reliability of vehicle components.

An optical system according to an exemplary embodiment will be described in detail below.

The optical system 1000 according to the embodiment may include a plurality of lenses 100 and an image sensor 300 . In detail, the optical system 1000 according to the embodiment may include two or more lenses. For example, the optical system 1000 may include three lenses, and the first lens 110, the second lens 120, and the third lens 130 are sequentially disposed from the object side to the sensor side. and an image sensor 300 . The first to third lenses 110 , 120 , and 130 may be sequentially disposed along the optical axis OA of the optical system 1000 .

In this case, light corresponding to object information may pass through the first lens 110 , the second lens 120 , and the third lens 130 and be incident on the image sensor 300 .

Each of the plurality of lenses 100 may include an effective area and an ineffective area. The effective area may be an area through which light incident to each of the first to third lenses 110, 120, and 130 passes. That is, the effective area may be an area in which the incident light is refracted to implement optical characteristics.

The non-effective area may be arranged around the effective area. The ineffective area may be an area in which the light is not incident. That is, the non-effective area may be an area unrelated to the optical characteristics. Also, the non-effective area may be an area fixed to a barrel (not shown) accommodating the lens.

The image sensor 300 may detect light. In detail, the image sensor 300 may detect light sequentially passing through the plurality of lenses 100 , and in detail the first to third lenses 110 , 120 , and 130 . The image sensor 300 may include a device capable of sensing incident light, such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).

The image sensor 300 may include a plurality of pixels having a set size. For example, the pixel size of the image sensor 300 may be about 3 μm.

The image sensor 300 may detect light of a set wavelength. For example, the image sensor 300 may detect infrared (IR) light. In detail, the image sensor 300 may detect near infrared ray light of about 1500 nm or less. For example, the image sensor may detect light in a wavelength band of about 880 nm to about 1000 nm.

The optical system 1000 according to the embodiment may further include a cover glass 400 and a filter 500 .

The cover glass 400 may be disposed between the plurality of lenses 100 and the image sensor 300 . The cover glass 400 may be disposed adjacent to the image sensor 300 . The cover glass 400 may have a shape corresponding to that of the image sensor 300 . The cover glass 400 may be provided in a size equal to or greater than that of the image sensor 300 to protect an upper portion of the image sensor 300 .

Also, the filter 500 may be disposed between the plurality of lenses 100 and the image sensor 300 . The filter 500 may be disposed between the image sensor 300 and a last lens (third lens 130 ) closest to the image sensor 300 among the plurality of lenses 100 . In detail, the filter 500 may be disposed between the last lens (third lens 130) and the cover glass 400.

The filter 500 may pass light of a set wavelength band and filter light of a different wavelength band. The filter 500 may pass light of a wavelength band corresponding to light received by the image sensor 300 and may block light of a wavelength band not corresponding to the light received. In detail, the filter 500 can pass light in the infrared wavelength band and block light in the ultraviolet and visible ray bands. For example, the filter 500 may include at least one of an IR pass filter and an IR cut-off filter.

In addition, the optical system 1000 according to the embodiment may include a stop (not shown). The diaphragm may control the amount of light incident to the optical system 1000 .

The diaphragm may be disposed at a set position. For example, the diaphragm may be located in front of the first lens 110 or between two lenses selected from among the first to third lenses 110 , 120 , and 130 . For example, the diaphragm may be located behind the first lens 110 .

In addition, at least one lens of the first to third lenses 110, 120, and 130 may serve as a diaphragm. In detail, an object-side surface or a sensor-side surface of one lens selected from among the first to third lenses 110, 120, and 130 may serve as a diaphragm for adjusting the amount of light. For example, the sensor-side surface (second surface S2) of the first lens 110 may serve as a diaphragm.

Hereinafter, the plurality of lenses 100 according to the embodiment will be described in more detail.

The first lens 110 may have positive (+) refractive power along the optical axis OA. The first lens 110 may include a glass material.

The first lens 110 may include a first surface S1 defined as an object side surface and a second surface S2 defined as a sensor side surface. The first surface S1 may have a convex shape along the optical axis OA, and the second surface S2 may be concave along the optical axis OA. That is, the first lens 110 may have a meniscus shape convex from the optical axis OA toward the object side.

At least one of the first surface S1 and the second surface S2 may be a sphere. For example, both the first surface S1 and the second surface S2 may be spheres.

The second lens 120 may have positive (+) refractive power along the optical axis OA. The second lens 120 may be provided with a material different from that of the first lens 110 . For example, the second lens 120 may be made of a plastic material.

The second lens 120 may include a third surface S3 defined as an object side surface and a fourth surface S4 defined as a sensor side surface. The third surface S3 may have a concave shape along the optical axis OA, and the fourth surface S4 may be convex along the optical axis OA. That is, the second lens 120 may have a meniscus shape convex from the optical axis OA toward the sensor.

At least one of the third and fourth surfaces S3 and S4 may be an aspheric surface. For example, both the third surface S3 and the fourth surface S4 may be aspheric surfaces (Asphere).

The third lens 130 may have negative (-) refractive power on the optical axis OA. The third lens 130 may be provided with a material different from that of the first lens 110 . Also, the third lens 130 may be made of the same material as the second lens 120 . For example, the third lens 130 may be made of a plastic material.

The third lens 130 may include a fifth surface S5 defined as an object side surface and a sixth surface S6 defined as a sensor side surface. The fifth surface S5 may have a convex shape along the optical axis OA, and the sixth surface S6 may be concave along the optical axis OA. That is, the third lens 130 may have a meniscus shape convex from the optical axis OA toward the object side.

At least one surface of the fifth surface S5 and the sixth surface S6 may be an aspherical surface (Asphere). For example, both the fifth surface S5 and the sixth surface S6 may be aspheric surfaces (Asphere).

The optical system 1000 according to the embodiment may satisfy at least one of equations described below. Accordingly, the optical system 1000 according to the embodiment can prevent or minimize a change in optical properties depending on the temperature in a temperature range from low to high, and can implement improved optical properties at various temperatures. In addition, the optical system 1000 according to the embodiment may have improved distortion and aberration characteristics at various temperatures as it satisfies at least one of equations to be described later.

Equations will be described below. In addition, terms expressed in some equations will be described with reference to FIG. 30 .

[Equation 1]

1.7 ≤ nt_1 ≤ 2.3

In Equation 1, nt_1 is the refractive index of the first lens 110 for light in a t-line (1013.98 nm) or d-line (587.6 nm) wavelength band.

[Equation 2]

nt_2 < nt_1

nt_3 < nt_1

In Equation 2, nt_1 is the refractive index of light in the t-line or d-line wavelength band of the first lens 110, and nt_2 is the t-line or d-line wavelength band of the second lens 120 It is the refractive index for light, and nt_3 is the refractive index for light in the t-line or d-line wavelength band of the third lens 130.

[Equation 3]

dnt_1/dt ≥ 0

dnt_2/dt < 0

dnt_3/dt < 0

|dnt_2/dt| / |dnt_1/dt| > 20

In Equation 3, dt denotes a temperature change amount (° C.), and dnt_1 is a refractive index change of the first lens 110 in the entire wavelength band, particularly in the d-line wavelength band. That is, dnt_1/dt denotes a change in the refractive index of the first lens 110 according to a temperature change in the entire wavelength band, particularly in the d-line wavelength band. In addition, dnt_2 is the refractive index change of the second lens 120 in the entire wavelength band, particularly in the d-line wavelength band, and dnt_2 / dt is the second lens according to the temperature change in the entire wavelength band, particularly in the d-line wavelength band. (120) means the refractive index change. In addition, dnt_3 is a change in the refractive index of the third lens 130 in the entire wavelength band, particularly in the d-line wavelength band, and dnt_3 / dt is the change in temperature of the third lens 130 in the entire wavelength band, particularly in the d-line wavelength band. (130) means the refractive index change. In Equation 3, dt may be a temperature change from -40 ° C to 90 ° C.

When the optical system 1000 according to the embodiment satisfies at least one of Equations 1 to 3, the optical system 1000 may have good optical performance in a temperature range of low to high temperatures.

[Equation 4]

1 ≤ |v1 - v2| ≤ 10

1 ≤ |v1 - v3| ≤ 10

50 ≤ v1 + v2 + v3 ≤ 200

In Equation 4, v1 is the Abbe number of the first lens 110, v2 is the Abbe number of the second lens 120, and v3 is the Abbe number of the third lens 130.

When the optical system 1000 according to the embodiment satisfies Equation 4, the optical system 1000 may have improved chromatic aberration characteristics.

In detail, Equation 4 may satisfy 50 ≤ v1 + v2 + v3 ≤ 150 for more improved incident light control characteristics and aberration control characteristics in a specific wavelength band.

In more detail, Equation 4 above may satisfy 50 ≤ v1 + v2 + v3 ≤ 70 for more improved incident light control characteristics and aberration control characteristics in a specific wavelength band.

[Equation 5]

1mm ≤ TTL ≤ 9mm

In Equation 5, TTL is the optical axis OA from the object-side surface (first surface S1) of the first lens 110 to the top surface of the image sensor 300 in a room temperature environment (about 22° C.) is the distance (mm) from In detail, Equation 5 above may satisfy 2mm ≤ TTL ≤ 8mm. Preferably, Equation 5 above may satisfy 3mm ≤ TTL ≤ 7mm.

[Equation 6]

|Diop_L1| > |Diop_L2| > |Diop_L3|

In Equation 6, Diop_L1 is the diopter value of the first lens 110 at room temperature (about 22 ° C), and Diop_L2 is the diopter value of the second lens 120 at room temperature (about 22 ° C). , and Diop_L3 is a diopter value of the third lens 130 at room temperature (about 22° C.).

[Equation 7]

1.5 < |Diop_L1| / |Diop_L2| < 2.5

In Equation 7, Diop_L1 is the diopter value of the first lens 110 at room temperature (about 22 ° C), and Diop_L2 is the diopter value of the second lens 120 at room temperature (about 22 ° C). am.

[Equation 8]

10 < Diop_L1 / Diop_L3 < 100

In Equation 8, Diop_L1 is the diopter value of the first lens 110 at room temperature (about 22 ° C), and Diop_L3 is the diopter value of the third lens 130 at room temperature (about 22 ° C). am.

When the optical system 1000 according to the embodiment satisfies at least one of Equations 6 to 8, the plurality of lenses 100 of the optical system 1000 are disposed at the center and the periphery of the FOV, and at a low temperature to It can have good optical performance in a high temperature range.

[Equation 9]

1.8 ≤ F# ≤ 2.2

In Equation 9, F# is an F-number of the optical system 1000 in an environment of room temperature (about 22°C), low temperature (about -40°C), and high temperature (about 90°C).

[Equation 10]

1.2mm ≤ D_1 ≤ 2.2mm

In Equation 10, D_1 is the center thickness (see FIG. 74) of the first lens 110 at room temperature (about 22° C.) and is the thickness (mm) of the first lens 110 on the optical axis OA. In detail, Equation 10 above may be 1.3mm ≤ D_1 ≤ 2.0mm. Preferably, Equation 10 above may satisfy 1.5mm ≤ D_1 ≤ 1.8mm.

When the optical system 1000 according to the embodiment satisfies Equation 10, the optical system 1000 has improved optical performance and can be easily manufactured. For example, when the center thickness of the first lens 110 is less than about 1.2 mm, the focal length of the first lens 110 becomes long, and it may be difficult to manufacture a glass lens. In addition, when the center thickness of the first lens 110 exceeds about 2.2 mm, the focal length of the first lens 110 decreases, and thus the overall optical performance of the optical system 1000 may deteriorate.

[Equation 11]

0.15 ≤ D_1 / TTL ≤ 0.35

In Equation 11, D_1 is the center thickness (see FIG. 74) of the first lens 110 at room temperature (about 22° C.) and is the thickness (mm) of the first lens 110 on the optical axis OA. . In addition, TTL is measured along the optical axis OA from the object-side surface (first surface S1) of the first lens 110 to the upper surface of the image sensor 300 in a room temperature environment (about 22° C.). is the distance (mm).

When the optical system 1000 according to the embodiment satisfies Equation 11 at room temperature (about 22° C.), the optical system 1000 changes its optical performance according to the temperature change at room temperature (about 22° C.) and high temperature (about 90° C.). can be prevented or minimized. In detail, Equation 11 may satisfy 0.20 ≤ D_1/TTL ≤ 0.3 for more improved optical performance in various temperature ranges.

[Equation 12]

1.5 < D_1 / D_2 < 2.5

In Equation 12, D_1 is the center thickness of the first lens 110 at room temperature (about 22° C.) and is the thickness (mm) of the first lens 110 on the optical axis OA. In addition, D_2 is the center thickness of the second lens 120 at room temperature (about 22° C.) and is the thickness (mm) of the second lens 120 on the optical axis OA. (See Fig. 74)

When the optical system 1000 according to the embodiment satisfies Equation 12, the optical system 1000 may improve aberration characteristics.

[Equation 13]

3.0 < D_1 / D_3 < 4.0

In Equation 13, D_1 is the central thickness of the first lens 110 at room temperature (about 22° C.) and is the thickness (mm) of the first lens 110 on the optical axis OA. In addition, D_3 is the center thickness of the third lens 130 at room temperature (about 22° C.) and is the thickness (mm) of the third lens 130 on the optical axis OA. (See Fig. 74)

When the optical system 1000 according to the embodiment satisfies Equation 13, the optical system 1000 may improve aberration characteristics.

[Equation 14]

|f1| < |f2| < |f3|

In Equation 14, f1 is the focal length (mm) of the first lens 110 at room temperature (about 22° C.), and f2 is the focal length (mm) of the second lens 120 at room temperature (about 22° C.) , and f3 is the focal length (mm) of the third lens 130 at room temperature (about 22° C.).

At this time, the focal length f1 of the first lens 110 at room temperature (about 22° C.) may be greater than 4 mm and less than 7 mm. Also, the focal length f2 of the second lens 120 at room temperature (about 22° C.) may be greater than 5 mm and less than 10 mm. Also, the focal length f3 of the third lens 130 at room temperature (about 22° C.) may be larger than -30 mm and smaller than -15 mm.

When the optical system 1000 according to the embodiment satisfies Equation 14, the plurality of lenses 100 of the optical system 1000 may have good optical performance in the center and periphery of the FOV.

[Equation 15]

0.3 < |f1 / f2| < 1.2

In Equation 15, f1 is the focal length (mm) of the first lens 110 at room temperature (about 22° C.), and f2 is the focal length (mm) of the second lens 120 at room temperature (about 22° C.) am.

When the optical system 1000 according to the embodiment satisfies Equation 15, in the optical system 1000, the first lens 110 and the second lens 120 may have appropriate refractive power for controlling the incident light path. And, the optical system 1000 may have improved resolving power.

[Equation 16]

1 < |f3 / f1| < 10

In Equation 16, f1 is the focal length (mm) of the first lens 110 at room temperature (about 22° C.), and f3 is the focal length (mm) of the third lens 130 at room temperature (about 22° C.) am.

When the optical system 1000 according to the embodiment satisfies Equation 16, the optical system 1000 can have improved resolving power by properly controlling the refractive power of the first lens 110 and the third lens 130. .

[Equation 17]

0.4 < |L1R1| / |L1R2| < 0.8

In Equation 17, L1R1 is the radius of curvature of the object-side surface (first surface S1) of the first lens 110 at room temperature (about 22° C.), and L1R2 is the radius of curvature of the first lens 110 at room temperature (about 22° C.). (110) is the radius of curvature of the sensor-side surface (second surface S2).

When the optical system 1000 according to the embodiment satisfies Equation 17, the optical system 1000 may control incident light and may have improved aberration control characteristics.

[Equation 18]

1.0 < |L2R1| / |L2R2| < 2.5

In Equation 18, L2R1 is the radius of curvature of the object-side surface (third surface S3) of the second lens 120 at room temperature (about 22° C.), and L2R2 is the second lens at room temperature (about 22° C.). (120) is the radius of curvature of the sensor-side surface (fourth surface S4).

When the optical system 1000 according to the embodiment satisfies Equation 18, the optical system 1000 may have improved aberration control characteristics.

[Equation 19]

1.1 < |L3R1| / |L3R2| < 1.5

In Equation 19, L3R1 is the radius of curvature of the object-side surface (fifth surface S5) of the third lens 130 at room temperature (about 22° C.), and L3R2 is the third lens at room temperature (about 22° C.). (130) is the radius of curvature of the sensor-side surface (the sixth surface (S6)).

When the optical system 1000 according to the embodiment satisfies Equation 19, the optical system 1000 may have good optical performance in the periphery of the FOV.

[Equation 20]

0.5 < CA_L1S1 / CA_L3S2 < 1.0

In Equation 20, CA_L1S1 is the size of the effective diameter (CA, Clear Aperture) of the object-side surface (first surface S1) of the first lens 110 at room temperature (about 22° C.), and CA_L3S2 is room temperature (about 22° C.). °C) is the size of the effective diameter of the sensor-side surface (the sixth surface S6) of the third lens 130.

When the optical system 1000 according to the embodiment satisfies Equation 20, the optical system 1000 can control incident light and has an appropriate size that can be provided in a slim and compact structure while maintaining optical performance. can

[Equation 21]

CA_L1S2 ≤ CA_L2S2 ≤ CA_L3S2

CA_L1S2 ≤ CA_L2S1 ≤ CA_L3S1

CA_L1S2 ≤ CA_L2S1 ≤ CA_L2S2 ≤ CA_L3S1 ≤ CA_L3S2

In Equation 21, CA_L1S2 is the size of the effective diameter of the surface on which the diaphragm is disposed at room temperature (about 22° C.). That is, CA_L1S2 is the size of the effective diameter (CA, Clear Aperture) of the sensor-side surface (second surface S2) of the first lens 110, and CA_L2S1 is the size of the second lens 120 at room temperature (about 22 ° C). ) is the size of the effective diameter (CA, Clear Aperture) of the object-side surface (third surface (S3)) of the second lens 120, and CA_L2S2 is the object-side surface (fourth surface (fourth surface ( S4)) is the size of the effective diameter (CA, Clear Aperture), and L3S1 is the size of the effective diameter (CA, Clear Aperture), and CA_L3S2 is the size of the effective diameter of the sensor-side surface (the sixth surface S6) of the third lens 130 at room temperature (about 22° C.).

When the optical system 1000 according to the embodiment satisfies Equation 21, that is, when the size of the effective diameter of the lens surface on which the diaphragm is disposed or the lens surface disposed closest to the diaphragm is smaller than the size of the effective diameter of the lens disposed close to the sensor Alternatively, when the effective diameter of each surface of the lens increases from the diaphragm to the sensor side, the optical system 1000 can control incident light and have an appropriate size that can be provided in a slim and compact structure while maintaining optical performance. there is.

[Equation 22]

0.2 < d12 / D_1 < 0.9

In Equation 20, d12 is the distance (mm) between the optical axes OA of the first lens 110 and the second lens 120 at room temperature (about 22° C.), and D_1 is at room temperature (about 22° C.) The central thickness of the first lens 110 is the thickness (mm) in the optical axis OA of the first lens 110 . (See Fig. 30)

When the optical system 1000 according to the embodiment satisfies Equation 22, the optical system 1000 may control incident light and may have improved aberration control characteristics.

[Equation 23]

0.2 ≤ CA_S _max / ImgH ≤ 0.7

In Equation 23, CA_Smax is the size of the effective diameter of the lens surface having the largest effective diameter CA at room temperature (about 22 ° C) among the lens surfaces of the plurality of lenses 100 included in the optical system 1000 ( CA) is.

In addition, the ImgH ranges from the 0 field area at the center of the top surface of the image sensor 300 overlapping the optical axis OA at room temperature (about 22° C.) to the 1.0 field area of the image sensor 300. It is twice the distance in the vertical direction of the optical axis OA. That is, the ImgH means the total diagonal length (mm) of the image sensor 300 at room temperature (about 22° C.).

When the optical system 1000 according to the embodiment satisfies Equation 23, the optical system 1000 has good optical performance at the center and periphery of the FOV and can be provided in a slim and compact structure.

[Equation 24]

3 ≤ EFL ≤ 5

In Equation 24, EFL (Effective Focal Length) means the effective focal length (mm) of the optical system 1000 at room temperature (about 22° C.).

[Equation 25]

40 degree ≤ FOV ≤ 50 degree

In Equation 25, FOV means the angle of view (FOV) of the optical system 1000 in an environment of room temperature (about 22°C), low temperature (about -40°C), and high temperature (about 90°C).

[Equation 26]

1.2 < TTL / ImgH < 1.6

In Equation 26, TTL is the distance from the object-side surface (first surface S1) of the first lens 110 to the upper surface of the image sensor 300 at room temperature (about 22° C.) along the optical axis OA. is the distance (mm).

In addition, the ImgH ranges from the 0 field area at the center of the top surface of the image sensor 300 overlapping the optical axis OA at room temperature (about 22° C.) to the 1.0 field area of the image sensor 300. It is twice the distance in the vertical direction of the optical axis OA. That is, the ImgH means the total diagonal length (mm) of the image sensor 300 at room temperature (about 22° C.).

When the optical system 1000 according to the embodiment satisfies Equation 26, the optical system 1000 is a BFL for applying a relatively large image sensor 300, for example, a large image sensor 300 around 1 inch. (Back focal length) and can have a smaller TTL, so it can realize high quality and have a slim structure.

[Equation 27]

0.2 < BFL / ImgH < 0.5

In Equation 27, BFL (Back focal length) is the distance from the apex of the sensor-side surface of the lens closest to the image sensor 300 to the top surface of the image sensor 300 at room temperature (about 22 ° C.) on the optical axis OA. is the distance (mm).

In addition, the ImgH ranges from the 0 field area at the center of the top surface of the image sensor 300 overlapping the optical axis OA at room temperature (about 22° C.) to the 1.0 field area of the image sensor 300. It is twice the distance in the vertical direction of the optical axis OA. That is, the ImgH means the total diagonal length (mm) of the image sensor 300 at room temperature (about 22° C.).

When the optical system 1000 according to the embodiment satisfies Equation 27, the optical system 1000 is used to apply a relatively large image sensor 300, for example, a large image sensor 300 around 1 inch. A back focal length (BFL) can be secured and a distance between the last lens and the image sensor 300 can be minimized, so that good optical characteristics can be obtained at the center and the periphery of the FOV.

[Equation 28]

3 < TTL / BFL < 5

In Equation 286, TTL is the distance from the object-side surface (first surface S1) of the first lens 110 to the upper surface of the image sensor 300 at room temperature (about 22° C.) along the optical axis OA. is the distance (mm).

In addition, BFL (Back focal length) is the distance in the optical axis (OA) from the apex of the sensor-side surface of the lens closest to the image sensor 300 to the top surface of the image sensor 300 at room temperature (about 22 ° C) ( mm) is.

When the optical system 1000 according to the embodiment satisfies Equation 28, the optical system 1000 secures BFL and can be provided slim and compact.

[Equation 29]

0.4 < EFL / TTL < 1.0

In Equation 29, EFL (Effective Focal Length) means the effective focal length (mm) of the optical system 1000 at room temperature (about 22° C.).

In addition, TTL is the distance in the optical axis OA from the object side surface (first surface S1) of the first lens 110 to the upper surface of the image sensor 300 at room temperature (about 22° C.) ( mm) is.

When the optical system 1000 according to the embodiment satisfies Equation 29, the optical system 1000 can be provided slim and compact.

[Equation 30]

2 < EFL / BFL < 4

In Equation 30, EFL (Effective Focal Length) means an effective focal length (mm) of the optical system 1000 at room temperature (about 22° C.).

In addition, BFL (Back focal length) is the distance in the optical axis (OA) from the apex of the sensor-side surface of the lens closest to the image sensor 300 to the top surface of the image sensor 300 at room temperature (about 22 ° C) ( mm) is.

When the optical system 1000 according to the embodiment satisfies Equation 30, the optical system 1000 may have a set angle of view, have an appropriate focal length, and may be provided slim and compact. In addition, the optical system 1000 can minimize the distance between the last lens and the image sensor 300, so that it can have good optical characteristics in the periphery of the field of view (FOV).

[Equation 31]

0.7 < EFL / ImgH < 1.2

In Equation 31, EFL (Effective Focal Length) means the effective focal length (mm) of the optical system 1000 at room temperature (about 22° C.).

In addition, the ImgH ranges from the 0 field area at the center of the top surface of the image sensor 300 overlapping the optical axis OA at room temperature (about 22° C.) to the 1.0 field area of the image sensor 300. It is twice the distance in the vertical direction of the optical axis OA. That is, the ImgH means the total diagonal length (mm) of the image sensor 300 at room temperature (about 22° C.).

When the optical system 1000 according to the embodiment satisfies Equation 31, the optical system 1000 applies a relatively large image sensor 300, for example, a large image sensor 300 around 1 inch, and improves It may have an aberration characteristic.

[Equation 32]

0.2 < D_1_ET / D_1 < 1.7

In Equation 32, D_1 is the center thickness of the first lens 110 at room temperature (about 22° C.) and is the thickness (mm) of the first lens 110 on the optical axis OA. Also, D_1_ET means the thickness (mm) in the optical axis (OA) direction at the end of the effective area of the first lens 110 at room temperature (about 22° C.). In detail, referring to FIG. 30, D_1_ET is the end of the effective area of the object side surface (first surface S1) of the first lens 110 and the sensor side surface (second surface S2) of the first lens 110. )) means the distance (mm) in the direction of the optical axis (OA) between the ends of the effective area. D_1_ET may be the thickness of the flange portion outside the effective diameter of the first lens 110 .

When the optical system 1000 according to the embodiment satisfies Equation 32, the optical system 1000 can control incident light and can have improved aberration control characteristics in a low to high temperature range.

In detail, Equation 32 may satisfy 0.4 < D_1_ET / D_1 < 1.5 for more improved incident light control characteristics and aberration control characteristics in a low to high temperature range. In more detail, Equation 30 may satisfy 0.6 < D_1_ET / D_1 < 1.0 for more improved incident light control characteristics and aberration control characteristics.

[Equation 33]

0.3 < D_2_ET / D_2 < 1.7

In Equation 33, D_2 is the central thickness of the second lens 120 at room temperature (about 22° C.) and is the thickness (mm) of the second lens 120 on the optical axis OA. Also, D_2_ET means the thickness (mm) in the optical axis (OA) direction at the end of the effective area of the second lens 120 at room temperature (about 22° C.). In detail, referring to FIG. 30, D_2_ET is the end of the effective area of the object side surface (third surface S3) of the second lens 120 and the sensor side surface (fourth surface S4) of the second lens 120. )) means the distance (mm) in the direction of the optical axis (OA) between the ends of the effective area. D_2_ET may be the thickness of the flange portion outside the effective mirror of the second lens.

When the optical system 1000 according to the embodiment satisfies Equation 33, the optical system 1000 may have improved chromatic aberration control characteristics in a low to high temperature range.

In detail, Equation 33 may satisfy 0.4 < D_2_ET / D_2 < 1.5 for more improved chromatic aberration control characteristics in a low to high temperature range. In more detail, Equation 33 may satisfy 0.5 ≤ D_2_ET / D_2 ≤ 1.0 for more improved chromatic aberration control characteristics.

[Equation 34]

0.3 < D_3_ET / D_3 < 1.7

In Equation 34, D_3 is the central thickness of the third lens 130 at room temperature (about 22° C.) and is the thickness (mm) of the third lens 130 on the optical axis OA. Also, D_3_ET means the thickness (mm) in the optical axis (OA) direction at the end of the effective area of the third lens 130 at room temperature (about 22° C.). In detail, referring to FIG. 30 , D_3_ET is the end of the effective area of the object-side surface (fifth surface S5) of the third lens 130 and the sensor-side surface (sixth surface S6) of the third lens 130. )) means the distance (mm) in the direction of the optical axis (OA) between the ends of the effective area. D_3_ET may be the thickness of the flange portion outside the effective mirror of the third lens.

When the optical system 1000 according to the embodiment satisfies Equation 34, the optical system 1000 may have improved distortion control characteristics in a low to high temperature range and have good optical performance in the periphery of the FOV. can

In detail, Equation 34 may satisfy 0.5 < D_3_ET / D_3 < 1.6 for more improved distortion control characteristics in various temperature ranges. In more detail, Equation 34 may satisfy 1.0 < D_3_ET / D_3 < 1.5 for more improved distortion control characteristics.

[Equation 35]

0.1 < d23 / d23_max < 1

In Equation 35, d23 is the distance (mm) between the optical axes OA of the second lens 120 and the third lens 130 at room temperature (about 22° C.), and d23_max is at room temperature (about 22° C.) The maximum distance between the sensor-side surface of the second lens 120 (fourth surface S4) and the object-side surface of the third lens 130 (fifth surface S5) in the direction of the optical axis OA. (mm).

When the optical system 1000 according to the embodiment satisfies Equation 35, the optical system 1000 may improve chromatic aberration and distortion aberration characteristics of the peripheral portion of the field of view (FOV) in a low to high temperature range.

In detail, Equation 35 above may satisfy 0.2 < d23 / d23_max < 0.9 in order to further improve the optical performance of the periphery of the FOV in various temperature ranges. In more detail, Equation 33 may satisfy 0.25 < d23 / d23_max < 0.8 in order to further improve the optical performance of the periphery in various temperature ranges.

[Equation 36]

1 < d23_Sag_L3S1_max / d23 < 5

In Equation 36, d23 is the distance (mm) in the optical axis (OA) of the second lens 120 and the third lens 130 at room temperature (about 22 ° C), and d23_Sag_L3S1_max is the third lens 130 From the maximum Sag value of the object side surface (fifth surface S5) of the sensor side (fourth surface S4) of the second lens 120 facing the Sag value in the optical axis OA direction. It means the distance (mm) in the direction of the optical axis (OA). (See Fig. 30)

When the optical system 1000 according to the embodiment satisfies Equation 36, the optical system 1000 may improve peripheral optical performance of the FOV in a low to high temperature range.

In detail, Equation 36 above may satisfy 1.3 < d23_Sag_L3S1_max / d23 < 4 in order to further improve the optical performance of the periphery of the FOV in various temperature ranges. In more detail, Equation 34 may satisfy 1.5 < d23_Sag_L3S1_max / d23 < 3 in order to further improve the optical performance of the periphery in various temperature ranges.

[Equation 37]

0.2 < L_Sag_L3S1 / CA_L3S1 < 0.8

In Equation 37, L_Sag_L3S1 is the maximum |Sag value| of the object-side surface (fifth surface S5) of the third lens 130 from the optical axis OA at room temperature (approximately 22° C.) CA_L3S1 means the distance in the vertical direction, and CA_L3S1 means the size of the effective mirror of the object-side surface (fifth surface S5) of the third lens 130 at room temperature (about 22° C.). (See Fig. 74)

When the optical system 1000 according to the embodiment satisfies Equation 37, the optical system 1000 may improve peripheral optical performance of the FOV in a low to high temperature range.

In detail, Equation 37 above may satisfy 0.3 < L_Sag_L3S1 / CA_L3S1 < 0.7 in order to further improve the optical performance of the periphery of the FOV in various temperature ranges. In more detail, Equation 37 may satisfy 0.4 < L_Sag_L3S1 / CA_L3S1 < 0.6 in order to further improve the optical performance of the periphery in various temperature ranges.

[Equation 38]

0.5 < |Sag_L3S1_max| < 1.5

In Equation 38, Sag_L3S1_max is the Sag value of the object side surface (fifth surface S5) of the third lens 130 on the optical axis OA at room temperature (about 22 ° C) and the ratio of the third lens 130 It means the difference from the maximum Sag value on the side of the object (the fifth surface S5).

When the optical system 1000 according to the embodiment satisfies Equation 38, the optical system 1000 may improve peripheral optical performance of the FOV in a low to high temperature range.

In detail, Equation 38 above is 0.7 < |Sag_L3S1_max| < 1.3 can be satisfied. In more detail, Equation 38 above is 0.9 < |Sag_L3S1_max| < 1.1 can be satisfied.

[Equation 39]

0.1 < L_Sag_L3S2 / CA_L3S2 < 1.2

In Equation 39, L_Sag_L3S2 is perpendicular to the optical axis OA from the optical axis OA to the maximum Sag value of the sensor side (the sixth surface S6) of the third lens 130 at room temperature (about 22 ° C). CA_L3S2 means the distance in a direction, and CA_L3S2 means the size of the effective diameter of the sensor-side surface (the sixth surface S6) of the third lens 130 at room temperature (about 22° C.). (See Fig. 74)

In detail, Equation 39 may satisfy 0.3 < L_Sag_L3S2 / CA_L3S2 < 1.0 in order to further improve the optical performance of the periphery of the FOV in various temperature ranges. In more detail, Equation 39 may satisfy 0.5 < L_Sag_L3S2 / CA_L3S2 < 0.8 in order to further improve the optical performance of the periphery in various temperature ranges.

When the optical system 1000 according to the embodiment satisfies at least one of Equations 38 and 39, the optical system 1000 can improve chromatic aberration and aberration characteristics in a low to high temperature range, and the FOV It can have good optical performance at the periphery as well as at the center of .

[Equation 40]

0.1 < |Sag_L3S2_max| < 0.4

In Equation 40, |Sag_L3S2_max| is the Sag value of the sensor side (sixth surface S6) of the third lens 130 along the optical axis OA at room temperature (about 22° C.) and the third lens 130 ) means the difference from the maximum Sag value of the sensor side (the sixth surface (S6)).

When the optical system 1000 according to the embodiment satisfies Equation 40, the optical system 1000 may improve peripheral optical performance of the FOV in a low to high temperature range.

In detail, Equation 40 above is 0.15 < |Sag_L3S2_max| < 0.35 can be satisfied. More specifically, Equation 40 above is 0.2 < |Sag_L3S2_max| < 0.3 can be satisfied.

[Equation 41]

0.2 < L3S2_max_sag to Sensor / BFL < 1

In Equation 41, BFL (Back focal length) means the distance (mm) on the optical axis OA from the apex of the sensor-side surface of the lens closest to the image sensor 300 to the upper surface of the image sensor 300 .

In addition, L3S2_max_sag to Sensor is the distance in the direction of the optical axis (OA) from the maximum Sag value of the sensor-side surface (the sixth surface (S6)) of the third lens 130 at room temperature (about 22° C.) to the image sensor 300. (mm).

When the optical system 1000 according to the embodiment satisfies Equation 41, the optical system 1000 can improve distortion aberration characteristics, can have good optical performance in the periphery of the field of view (FOV), and can be easily assembled. there is

In detail, Equation 41 may satisfy 0.3 < L3S2_max_sag to Sensor / BFL < 0.95 in order to further improve distortion aberration characteristics and optical performance and ease of assembly in the periphery of the field of view (FOV) in various temperature ranges. In more detail, Equation 37 may satisfy 0.4 < L3S2_max_sag to Sensor / BFL < 0.9 in order to further improve distortion aberration characteristics and optical performance and ease of assembly in the periphery of the field of view (FOV) in various temperature ranges.

[Equation 42]

3 < ∑Index < 10

In Equation 42, ∑Index means the sum of refractive indices at d-line of each of the first to third lenses 110, 120, and 130 at room temperature (about 22° C.).

When the optical system 1000 according to the embodiment satisfies Equation 42, the TTL of the optical system 1000 can be controlled in a low to high temperature range, and improved chromatic aberration and resolution characteristics can be obtained.

[Equation 43]

10 < ∑Abb / ∑Index < 50

In Equation 39, ∑Index means the sum of refractive indices at d-line of each of the first to third lenses 110, 120, and 130 at room temperature (about 22° C.). Also, ∑Abb means the sum of Abbe's numbers of each of the first to third lenses 110, 120, and 130 at room temperature (about 22° C.).

When the optical system 1000 according to the embodiment satisfies Equation 43, the optical system 1000 may have improved aberration characteristics and resolution in a low to high temperature range.

[Equation 44]

1 < CA_Smax / CA_Smin < 3

In Equation 44, CA_Smax is the size of the effective diameter of the lens surface having the largest effective diameter CA at room temperature (about 22 ° C) among the lens surfaces of the plurality of lenses 100 included in the optical system 1000 ( CA) is. Also, CA_Smin is the effective diameter size (CA) of the lens surface having the smallest effective diameter size (CA) at room temperature (about 22° C.) among the lens surfaces of the plurality of lenses 100 included in the optical system 1000. am.

When the optical system 1000 according to the embodiment satisfies Equation 44, the optical system 1000 may be provided with a slim and compact structure and may have an appropriate size for realizing optical performance in a low to high temperature range. there is.

[Equation 45]

1 < CA_Smax / CA_Aver < 3

In Equation 45, CA_Smax is the size of the effective diameter of the lens surface having the largest effective diameter CA at room temperature (about 22 ° C.) among the lens surfaces of the plurality of lenses 100 included in the optical system 1000 ( CA) is. CA_Aver means the average (mm) of the sizes of effective mirrors (CA) at room temperature (about 22° C.) of the lens surfaces (object side surface, sensor side surface) of the plurality of lenses 100 included in the optical system 1000. .

When the optical system 1000 according to the embodiment satisfies Equation 45, the optical system 1000 may be provided with a slim and compact structure and may have an appropriate size for realizing optical performance in a low to high temperature range. there is.

[Equation 46]

0.1 < CA_Smin / CA_Aver < 1

In Equation 46, CA_Smin is the size of the effective diameter of the lens surface having the smallest effective diameter size CA at room temperature (about 22 ° C.) among the lens surfaces of the plurality of lenses 100 included in the optical system 1000 ( CA) is. CA_Aver means the average (mm) of the sizes of effective mirrors (CA) at room temperature (about 22° C.) of the lens surfaces (object side surface, sensor side surface) of the plurality of lenses 100 included in the optical system 1000. .

When the optical system 1000 according to the embodiment satisfies Equation 46, the optical system 1000 may be provided with a slim and compact structure and may have an appropriate size for realizing optical performance in a low to high temperature range. there is.

[Equation 47]

0.1 < CA_Smax / ImgH < 1

In Equation 47, CA_Smax is the size of the effective diameter of the lens surface having the largest effective diameter CA at room temperature (about 22 ° C) among the lens surfaces of the plurality of lenses 100 included in the optical system 1000 ( CA) is.

In addition, the ImgH ranges from the 0 field area at the center of the top surface of the image sensor 300 overlapping the optical axis OA at room temperature (about 22° C.) to the 1.0 field area of the image sensor 300. It is twice the distance in the vertical direction of the optical axis OA. That is, the ImgH means the total diagonal length (mm) of the image sensor 300 at room temperature (about 22° C.).

When the optical system 1000 according to the embodiment satisfies Equation 47, the optical system 1000 has good optical performance in the center and periphery of the field of view (FOV) in a low to high temperature range, and has a slim and compact structure. can be provided.

[Equation 48]

0.5 < CA_L1S2 / CA_L2S1 < 1

In Equation 48, CA_L1S2 means the size (mm) of the effective diameter of the sensor-side surface (second surface S2) of the first lens 110 at room temperature (about 22 ° C), and CA_L2S1 is room temperature (about 22 ° C). ) means the size (mm) of the effective diameter of the object-side surface (third surface S3) of the second lens 120.

When the optical system 1000 according to the embodiment satisfies Equation 48, the optical system 1000 may have improved chromatic aberration control characteristics in a low to high temperature range.

[Equation 49]

In Equation 49, Z is Sag and may mean a distance in the optical axis direction from an arbitrary position on the aspherical surface to the apex of the aspherical surface.

Also, Y may mean a distance in a direction perpendicular to the optical axis from an arbitrary position on the aspherical surface to the optical axis.

Also, c may mean the curvature of the lens, and K may mean the conic constant.

Also, A, B, C, D, ... may mean an aspheric constant.

[Equation 50]

0 < d1Ap < 0.2

In Equation 50, d1Ap means the distance (mm) in the direction of the optical axis (OA) of the diaphragm 600 from the end of the effective mirror of the first lens 110 at room temperature (about 22° C.).

[Equation 51]

0.8 < CA_L1S2 / CA_Ap < 1.8

In Equation 51, CA_L1S2 means the size (mm) of the effective diameter of the sensor-side surface (second surface S2) of the first lens 110 at room temperature (about 22 ° C), and CA_Ap is room temperature (about 22 ° C). ) means the size (mm) of the effective diameter of the aperture 600.

When the optical system 1000 according to the embodiment satisfies Equations 50 and 51, the optical system 1000 may control incident light and may have improved aberration control characteristics.

[Equation 52]

0.95 ≤ EFL_R / EFL_H ≤ 1.05

In Equation 52, EFL_R means the effective focal length (mm) of the optical system 1000 at room temperature (about 22 ° C), and EFL_H is the effective focal length (mm) of the optical system 1000 at high temperature (about 90 ° C) means

[Equation 53]

0.95 ≤ EFL_R / EFL_L ≤ 1.05

In Equation 52, EFL_R means the effective focal length (mm) of the optical system 1000 at room temperature (about 22 ° C), and EFL_L means the effective focal length (mm) of the optical system 1000 at low temperature (about -40 ° C). ) means

[Equation 54]

0.95 ≤ FOV_R / FOV_H ≤ 1.05

In Equation 54, FOV_R means the angle of view (°) of the optical system 1000 at room temperature (about 22° C.), and FOV_H means the angle of view (°) of the optical system 1000 at high temperature (about 90° C.).

[Equation 55]

0.95 ≤ FOV_R / FOV_L ≤ 1.05

In Equation 54, FOV_R means the angle of view (°) of the optical system 1000 at room temperature (about 22° C.), and FOV_L means the angle of view (°) of the optical system 1000 at low temperature (about 90° C.).

When the optical system 1000 according to the embodiment satisfies Equations 52 to 55, the optical system 1000 may have good optical performance in a low to high temperature range.

In addition, a chief ray incident angle (CRA) of the optical system 1000 according to the embodiment may be about 20 degrees to about 30 degrees. In detail, the chief ray incidence angle (CRA) of the optical system 1000 may be about 24 degrees to about 26 degrees in a 1.0 field. In addition, optical distortion of the optical system 1000 may be ±4% or less in a 1.0 field.

In particular, in the optical system 1000 according to the embodiment, the first lens 110 may include a material different from that of the second lens 120 and the third lens 130 . For example, the first lens 110 may be made of a glass material, and the second lens 120 and the third lens 130 may be made of the same plastic material.

Figure 4 is data on the refractive index of the first lens 110 for light of various wavelengths in the temperature range from low temperature (-40 ℃) to high temperature (90 ℃), Figure 5 is the first lens 110 according to temperature change ) is a graph of the refractive index change.

6 is data on the refraction of the second lens 120 and the third lens 130 for light of various wavelengths in the temperature range from low temperature (-40 ° C) to high temperature (90 ° C), and FIG. It is a graph of the change in refractive index of the second lens 120 and the third lens 130 according to temperature change.

4 to 7 , the first lens 110, the second lens 120, and the third lens 130 may have different refractive index change characteristics according to temperature changes.

First, referring to FIGS. 4 and 5 , it can be seen that the first lens 110 has a very small refractive index that varies with temperature in a temperature range from low temperature (about -40° C.) to high temperature (about 90° C.). . In particular, it can be seen that the change in refractive index (dnt_1/dt) according to the temperature change of the first lens 110 has a positive number as shown in Equation 3 and has a positive slope as shown in FIG. 5 .

On the other hand, referring to FIGS. 6 and 7, the second lens 120 and the third lens 130 change according to the temperature in the temperature range of low temperature (about -40 ℃) to high temperature (about 90 ℃) It can be seen that the refractive index is relatively greater than that of the first lens 110 . In particular, the change in refractive index (dnt_2/dt, dnt_3/dt) according to the temperature change of the second lens 120 and the third lens 130 has a negative number as shown in Equation 3, and has a negative value as shown in FIG. It can be seen that it has a slope.

In this case, the first lens 110 may have a higher refractive index than the second lens 120 and the third lens 130 . In detail, the first lens 110 has a higher refractive index than the two lenses 120 and 130 in order to compensate for the second lens 120 and the third lens 130 having a relatively large refractive index change with temperature change. can have

In addition, the first lens 110 is configured to compensate for the second lens 120 and the third lens 130 having a relatively large refractive index change according to a temperature change, the second lens 120 and the third lens 120 It may have a larger diopter value than the lens 130 . Accordingly, the first lens 110 can effectively distribute the power of the optical system 1000 in a temperature range from low temperature (about -40°C) to high temperature (about 90°C). Accordingly, the optical system 1000 according to the embodiment may minimize or prevent deterioration of optical properties in environments of various temperatures and may have improved optical performance.

That is, in the optical system 1000 according to the embodiment, the first lens 110 may be provided with a material different from that of the second lens 120 and the third lens 130, and the above-described Equation 1 to Math At least one of Equation 51 may be satisfied. Accordingly, the optical system 1000 can prevent or minimize a change in optical properties depending on temperature, and can have improved optical properties at various temperatures.

In addition, the optical system 1000 according to the embodiment can prevent or minimize changes in distortion and aberration characteristics at various temperatures by satisfying at least one of Equations 1 to 51, thereby having improved optical characteristics. can

In addition, the distance between the plurality of lenses 100 in the optical system 1000 according to the embodiment may have a value set according to a region.

The first lens 110 and the second lens 120 may be spaced apart from each other by a first distance. The first distance may be a distance between the first lens 110 and the second lens 120 in the direction of the optical axis (OA).

The first distance between the first lens 110 and the second lens 120 may change according to positions. In detail, when the first interval has the optical axis OA as a starting point and the end point of the effective area of the sensor-side surface (second surface S2) of the first lens 110 as an end point, the optical axis from the optical axis OA It may change as it goes in the direction perpendicular to (OA). That is, the first distance may change from the optical axis OA toward the end of the effective mirror of the second surface S2.

The first distance may decrease from the optical axis OA to a first point L1 located on the second surface S2. Here, the first point L1 may be an end of the effective area of the second surface S2.

The first interval may have a maximum value along the optical axis OA. Also, the first interval may have a minimum value at the first point L1. In this case, the maximum value of the first interval may be about 1.1 times or more than the minimum value. In detail, the maximum value of the first interval may be about 1.1 to about 3 times the minimum value.

The second lens 120 and the third lens 130 may be spaced apart from each other by a second distance. The second distance may be a distance between the second lens 120 and the third lens 130 in the direction of the optical axis (OA).

The second interval may change depending on positions between the second lens 120 and the third lens 130 . In detail, when the second interval has the optical axis OA as a starting point and the end point of the effective area of the sensor-side surface (fourth surface S4) of the second lens 120 as an end point, the optical axis from the optical axis OA It may change as it goes in the direction perpendicular to (OA). That is, the second interval may change from the optical axis OA toward the end of the effective mirror of the fourth surface S4.

The second interval may increase from the optical axis OA toward the second point L2 located on the fourth surface S4. Here, the second point L2 may be an end of the effective area of the fourth surface S4.

The second interval may have a maximum value at the second point L2. Also, the second interval may have a minimum value along the optical axis OA. In this case, the maximum value of the second interval may be about twice or more than the minimum value. In detail, the maximum value of the second interval may be about 2 to about 4 times the minimum value.

Accordingly, the optical system 1000 may have improved optical characteristics. In detail, the first lens 110, the second lens 120, and the second lens 120 and the third lens 130 are spaced according to their positions (first distance, second distance). As it is spaced apart, the optical system 1000 can prevent or minimize a change in optical characteristics in a low to high temperature range. Therefore, the optical system and the camera module according to the embodiment may maintain improved optical characteristics in various temperature ranges.

Hereinafter, the optical system 1000 according to the first embodiment will be described in more detail with reference to FIGS. 8 to 29 .

8 to 29, the optical system 1000 according to the first embodiment includes a first lens 110, a second lens 120, and a third lens 130 sequentially arranged from the object side to the sensor side. ) and the image sensor 300. The first to third lenses 110 , 120 , and 130 may be sequentially disposed along the optical axis OA of the optical system 1000 .

In addition, in the optical system 1000 according to the first embodiment, the sensor side surface (second surface S2) of the first lens 110 and the object side surface (third surface S3) of the second lens 120 ) An aperture 600 may be disposed between.

In detail, the diaphragm 600 is formed between the sensor side surface (second surface S2) of the first lens 110 and the object side surface (third surface S3) of the second lens 120. 1 may be disposed spaced apart from the sensor-side surface (second surface S2) of the lens 110.

For example, the diaphragm 600 may be spaced apart from the sensor-side surface (second surface S2) of the first lens 110 as shown in Equations 50 and 51 above.

In addition, a filter 500 may be disposed between the plurality of lenses 100 and the image sensor 300, and a cover glass 400 may be disposed between the filter 500 and the image sensor 300. It can be.

9 shows the radius of curvature of the first to third lenses 110, 120, and 130, the thickness of each lens in the optical axis OA, and the optical axis OA according to the first embodiment. ), the distance between each lens, the refractive index for light in the t-line (1013.98 nm) wavelength band, the Abbe's Number, and the size of the clear aperture (CA). Here, the lens data described in FIG. 9 is data at room temperature (about 22° C.).

Referring to FIGS. 8 and 9 , the first lens 110 of the optical system 1000 according to the first embodiment may have a glass material and have positive (+) refractive power on the optical axis OA. Also, in the optical axis OA, the first surface S1 of the first lens 110 may have a convex shape, and the second surface S2 may be concave. The first lens 110 may have a meniscus shape convex from the optical axis OA toward the object side. The first surface S1 may be a sphere, and the second surface S2 may be a sphere.

10 is a vertical direction of the optical axis OA of each of the object-side surface (first surface S1) and sensor-side surface (second surface S2) of the first lens 110 at room temperature (approximately 22° C.). It is Sag data according to height (0.2mm interval).

In addition, FIG. 11 is data on the lens thickness according to the height (0.2 mm interval) of the optical axis OA in the vertical direction at room temperature (about 22° C.). In detail, D_1 of FIG. 11 is the central thickness of the first lens 110 and is the thickness (mm) of the first lens 110 on the optical axis OA. Also, D_1_ET in FIG. 11 means the thickness (mm) in the optical axis (OA) direction at the end of the effective area of the first lens 110 . In detail, between the end of the effective area of the object-side surface (first surface S1) of the first lens 110 and the end of the effective area of the sensor-side surface (second surface S2) of the first lens 110 means the distance (mm) in the direction of the optical axis (OA) of

Referring to FIGS. 9 to 11 , the thickness of the first lens 110 in the direction of the optical axis OA may decrease from the optical axis OA toward the end of the effective mirror of the first lens 110 . In detail, the thickness in the direction of the optical axis (OA) of the first lens 110 may have a maximum value in the optical axis (OA) in the range from the optical axis (OA) to the end of the effective mirror of the second surface (S2). It may have a minimum value at the end of the effective diameter of the second surface (S2).

Accordingly, the first lens 110 may have improved aberration control characteristics by controlling incident light.

The second lens 120 may be made of a plastic material and may have positive (+) refractive power in the optical axis OA. Also, in the optical axis OA, the third surface S3 of the second lens 120 may have a concave shape, and the fourth surface S4 may have a convex shape. The second lens 120 may have a meniscus shape convex from the optical axis OA toward the sensor. The third surface S3 may be an aspherical surface (Asphere), and the fourth surface S4 may be an aspherical surface (Asphere).

12 is a vertical direction of the optical axis OA of each of the object-side surface (third surface S3) and sensor-side surface (fourth surface S4) of the second lens 120 at room temperature (approximately 22° C.). It is Sag data according to height (0.2mm interval).

In addition, FIG. 13 is data on the lens thickness according to the height (0.2 mm interval) of the optical axis OA in the vertical direction at room temperature (about 22° C.). In detail, D_2 of FIG. 13 is the central thickness of the second lens 120 and is the thickness (mm) of the second lens 120 on the optical axis OA. Also, D_2_ET in FIG. 13 means the thickness (mm) in the optical axis (OA) direction at the end of the effective area of the second lens 120 . In detail, between the end of the effective area of the object-side surface (third surface S3) of the second lens 120 and the end of the effective area of the sensor-side surface (fourth surface S4) of the second lens 120 means the distance (mm) in the direction of the optical axis (OA) of

9, 12, and 13, the thickness of the second lens 120 in the direction of the optical axis OA may decrease from the optical axis OA toward the end of the effective mirror of the second lens 120. . In detail, the thickness in the direction of the optical axis (OA) of the second lens 120 may have a maximum value along the optical axis (OA) in a range from the optical axis (OA) to the end of the effective mirror of the third surface (S3). It may have a minimum value at the end of the effective diameter of the 3 planes (S3).

Accordingly, the second lens 120 may prevent or minimize a change in optical characteristics depending on the temperature in the low to high temperature range.

The third lens 130 may be made of a plastic material and may have negative (-) refractive power on the optical axis OA. In the optical axis OA, the fifth surface S5 of the third lens 130 may have a convex shape, and the sixth surface S6 may be concave. The third lens 130 may have a meniscus shape convex from the optical axis OA toward the object side. The fifth surface S5 may be an aspherical surface (Asphere), and the sixth surface S6 may be an aspheric surface (Asphere).

14 is a vertical direction of the optical axis OA of each of the object-side surface (fifth surface S5) and sensor-side surface (sixth surface S6) of the third lens 130 at room temperature (approximately 22° C.). It is Sag data according to height (0.2mm interval).

Also, FIG. 15 is data on the lens thickness according to the height of the optical axis OA in the vertical direction at room temperature (about 22° C.). In detail, D_3 of Table 9 is the center thickness of the first lens 110 and is the thickness (mm) of the first lens 110 on the optical axis OA. Also, D_3_ET in FIG. 15 means the thickness (mm) in the optical axis (OA) direction at the end of the effective area of the third lens 130 . In detail, between the end of the effective area of the object-side surface (fifth surface S5) of the third lens 130 and the end of the effective area of the sensor-side surface (sixth surface S6) of the third lens 130 means the distance (mm) in the direction of the optical axis (OA) of

9, 14, and 15, the thickness of the third lens 130 in the direction of the optical axis OA may increase from the optical axis OA toward the end of the effective mirror of the third lens 130. . In detail, the thickness in the direction of the optical axis (OA) of the second lens 120 is the maximum value at the end of the effective diameter of the fifth surface (S5) in the range from the optical axis (OA) to the end of the effective diameter of the fifth surface (S5). , and may have a minimum value on the optical axis OA.

Accordingly, the third lens 130 may prevent or minimize a change in optical characteristics depending on the temperature in the low to high temperature range.

In this case, the refractive power of the first lens 110 may be different from the refractive power of the second lens 120 and the third lens 130 . For example, the refractive power of the first lens 110 may be about 1.1 times greater than the refractive powers of the second lens 120 and the third lens 130 . In detail, the refractive power of the first lens 110 may be about 1.2 times or more than the refractive powers of the second lens 120 and the third lens 130 . In more detail, the refractive power of the first lens 110 may be about 1.3 times greater than the refractive powers of the second lens 120 and the third lens 130 .

Also, the refractive power of the second lens 120 may be different from the refractive power of the third lens 130 . For example, the refractive power of the second lens 120 may be about 1.5 times greater than the refractive power of the third lens 130 . In detail, the refractive power of the second lens 120 may be about twice or more than the refractive power of the third lens 130 . In more detail, the refractive power of the second lens 120 may be about 2.5 times greater than the refractive power of the third lens 130 .

Also, the Abbe number of the first lens 110 may be different from that of the second lens 120 and the third lens 130. For example, the Abbe number of the first lens 110 may be different from that of the second lens 120 and the third lens 130. Abbe numbers of the second lens 120 and the third lens 130 may differ within a range of 10 or less. In detail, the Abbe number of the first lens 110 may be greater than the Abbe numbers of the second lens 120 and the third lens 130 within a range of 10 or less.

In the optical system 1000 according to the first embodiment, values of aspheric coefficients of each lens surface are shown in FIG. 16 .

In addition, in the optical system 1000 according to the first embodiment, the distance (first distance) between the first lens 110 and the second lens 120 is the same as that of FIG. 17 at room temperature (about 22° C.), and the The distance (second distance) between the second lens 120 and the third lens 130 is shown in FIG. 18 at room temperature (about 22° C.).

Referring to FIG. 17 , the first distance may decrease from the optical axis OA toward the first point L1, which is the end of the effective mirror of the second surface S2. Here, the meaning of the first point L1 is the sensor side surface (second surface S2) of the first lens 110 and the object side surface (third surface S2) of the second lens 120 facing each other. As an approximate value of the effective radius value of the second surface S2 having a smaller effective diameter among the surfaces S3), it means an approximate value of 1/2 of the effective diameter value of the second surface S2 described in Table 3.

The first interval may have a maximum value at the optical axis OA and may have a minimum value at the first point L1. The maximum value of the first interval may be about 1.1 times to about 3 times the minimum value. For example, in the first embodiment, the maximum value of the first interval may be about 1.2 times the minimum value.

Also, referring to FIG. 18 , the second distance may increase from the optical axis OA toward the second point L2, which is the end of the effective mirror of the fourth surface S4. Here, the meaning of the second point L2 is the sensor side surface (fourth surface S4) of the second lens 120 and the object side surface (fifth surface S4) of the third lens 130 facing each other. As an approximate value of the effective radius value of the fourth surface S4 having a smaller effective diameter among the surfaces S5), it means an approximate value of 1/2 of the effective diameter value of the fourth surface S4 described in Table 3.

The second interval may have a maximum value at the second point L2 and may have a minimum value at the optical axis OA. The maximum value of the second interval may be about 2 times to about 4 times the minimum value. For example, in the first embodiment, the maximum value of the second interval may be about 2.1 times the minimum value.

Accordingly, the optical system 1000 may have improved optical characteristics. In detail, the first lens 110, the second lens 120, and the second lens 120 and the third lens 130 are spaced according to their positions (first distance, second distance). As it is spaced apart, the optical system 1000 can prevent or minimize a change in optical characteristics in a low to high temperature range. Therefore, the optical system and the camera module according to the embodiment may maintain improved optical characteristics in various temperature ranges.

19 is a graph of relative illumination for each field of the optical system according to the first embodiment, and FIG. 20 is data on distortion characteristics of the optical system according to the first embodiment. 19 and 20 are data obtained by measuring the optical system 1000 at room temperature (about 22° C.).

Referring to FIG. 19 , the optical system 1000 according to the first embodiment may have excellent light ratio characteristics in the 0 field area (center area) to 1.0 field area (edge area) of the image sensor 300 . For example, the optical system 1000 may have a peripheral light amount ratio of about 70% or more. In detail, in the optical system 1000, when the 0 field area is 100%, the light amount ratio of the 0.5 field area may be about 80% or more, and the light amount ratio of the 1.0 field area may be about 70% or more.

Also, referring to FIG. 20 , the optical system 1000 according to the first embodiment may have a barrel distortion shape in which an edge portion of an image is bent outward, and a distortion of about 0.9904% and about - It may have a TV-distortion of 0.8355%.

21 to 29 are graphs of diffraction MTF characteristics and aberration diagrams of the optical system 1000 according to temperature.

In detail, FIGS. 21 and 22 are graphs of the diffraction MTF characteristics of the optical system 1000 in a low temperature (-40°C) environment, and FIGS. 24 and 25 are the optical system in a room temperature (22°C) environment. 27 and 28 are graphs of the diffraction MTF characteristics of the optical system 1000 in a high temperature (90° C.) environment.

23, 26 and 29 are graphs of aberration diagrams of the optical system 1000 in low temperature (-40 ° C), room temperature (22 ° C) and high temperature (90 ° C) environments, from left to right. This is a graph measuring Longitudinal Spherical Aberration, Astigmatic Field Curves, and Distortion. In FIGS. 23, 26, and 29, the X-axis may indicate a focal length (mm) or distortion (%), and the Y-axis may mean the height of an image. In addition, a graph of spherical aberration is a graph of light in a wavelength band of about 920 nm, about 940 nm, and about 960 nm, and a graph of astigmatism and distortion is a graph of light in a wavelength band of 940 nm.

In the aberration diagrams of FIGS. 23, 26, and 29, it can be interpreted that the aberration correction function is better as each curve approaches the Y-axis. Referring to FIGS. 23, 26, and 29, according to the first embodiment In the optical system 1000, it can be seen that measurement values are adjacent to the Y-axis in almost all regions.

21 to 29, the optical system 1000 according to the first embodiment has little or no change in MTF characteristics and aberration characteristics even when the temperature is changed in the range of low temperature (-40 ° C) to high temperature (90 ° C). It can be seen that it is not large. In detail, it can be seen that the change in MTF properties at low temperature (-40 °C) and high temperature (90 °C) is less than 10% of that at room temperature (22 °C).

That is, the optical system 1000 according to the first embodiment can maintain excellent optical characteristics in various temperature ranges. In detail, in the optical system 1000, the first lens 110 is made of a different material from the second lens 120 and the third lens 130, for example, the first lens 110 is a glass material, the second lens 120 and the third lens 130 may include a plastic material. Accordingly, when the temperature increases, the refractive index of the first lens 110 may increase, and the refractive index of the second lens 120 and the third lens 130 may decrease.

At this time, the first to third lenses 110, 120, and 130 according to the first embodiment are provided with a set refractive index, shape, thickness, etc., and the change in focal length caused by the change in refractive index that changes according to temperature is mutually can compensate Accordingly, the optical system 1000 can prevent or minimize a change in optical properties in a temperature range from low temperature (−40° C.) to high temperature (90° C.) and maintain improved optical properties.

Hereinafter, the optical system 1000 according to the second embodiment will be described in more detail with reference to FIGS. 30 to 51 .

Referring to FIG. 30 , the optical system 1000 according to the second embodiment includes a first lens 110, a second lens 120, a third lens 130, and an image sequentially arranged from the object side to the sensor side. A sensor 300 may be included. The first to third lenses 110 , 120 , and 130 may be sequentially disposed along the optical axis OA of the optical system 1000 .

In addition, in the optical system 1000 according to the second embodiment, the sensor side surface (second surface S2) of the first lens 110 and the object side surface (third surface S3) of the second lens 120 ) An aperture 600 may be disposed between.

In detail, the diaphragm 600 is formed between the sensor side surface (second surface S2) of the first lens 110 and the object side surface (third surface S3) of the second lens 120. 1 may be disposed spaced apart from the sensor-side surface (second surface S2) of the lens 110.

For example, the diaphragm 600 may be spaced apart from the sensor-side surface (second surface S2) of the first lens 110 as shown in Equations 50 and 51 above.

In addition, a filter 500 may be disposed between the plurality of lenses 100 and the image sensor 300, and a cover glass 400 may be disposed between the filter 500 and the image sensor 300. It can be.

31 shows the radius of curvature of the first to third lenses 110, 120, and 130, the thickness of each lens on the optical axis OA, and the optical axis OA according to the second embodiment. ), the distance between each lens, the refractive index for light in the t-line (1013.98 nm) wavelength band, the Abbe's Number, and the size of the clear aperture (CA). Here, the lens data described in FIG. 31 is data at room temperature (about 22° C.).

Referring to FIGS. 30 and 31 , the first lens 110 of the optical system 1000 according to the second embodiment may include a glass material and may have positive (+) refractive power on the optical axis OA. Also, in the optical axis OA, the first surface S1 of the first lens 110 may have a convex shape, and the second surface S2 may be concave. The first lens 110 may have a meniscus shape convex from the optical axis OA toward the object side. The first surface S1 may be a sphere, and the second surface S2 may be a sphere.

32 is a vertical direction of the optical axis OA of each of the object-side surface (first surface S1) and sensor-side surface (second surface S2) of the first lens 110 at room temperature (approximately 22° C.). It is Sag data according to height (0.2mm interval).

In addition, FIG. 33 is data on the lens thickness according to the height (0.2 mm interval) of the optical axis OA in the vertical direction at room temperature (about 22° C.). In detail, D_1 of Table 17 is the center thickness of the first lens 110 and is the thickness (mm) of the first lens 110 on the optical axis OA. Also, D_1_ET in FIG. 33 means the thickness (mm) in the optical axis (OA) direction at the end of the effective area of the first lens 110 . In detail, between the end of the effective area of the object-side surface (first surface S1) of the first lens 110 and the end of the effective area of the sensor-side surface (second surface S2) of the first lens 110 means the distance (mm) in the direction of the optical axis (OA) of

Referring to FIGS. 31 to 33 , the thickness of the first lens 110 in the direction of the optical axis OA may decrease from the optical axis OA toward the end of the effective mirror of the first lens 110 . In detail, the thickness in the direction of the optical axis (OA) of the first lens 110 may have a maximum value in the optical axis (OA) in the range from the optical axis (OA) to the end of the effective mirror of the second surface (S2). It may have a minimum value at the end of the effective diameter of the second surface (S2).

Accordingly, the first lens 110 may have improved aberration control characteristics by controlling incident light.

The second lens 120 may be made of a plastic material and may have positive (+) refractive power in the optical axis OA. Also, in the optical axis OA, the third surface S3 of the second lens 120 may have a concave shape, and the fourth surface S4 may have a convex shape. The second lens 120 may have a meniscus shape convex from the optical axis OA toward the sensor. The third surface S3 may be an aspheric surface (Asphere), and the fourth surface S4 may be an aspheric surface (Asphere).

34 is a vertical direction of the optical axis OA of each of the object-side surface (third surface S3) and sensor-side surface (fourth surface S4) of the second lens 120 at room temperature (approximately 22° C.). It is Sag data according to height (0.2mm interval).

In addition, FIG. 35 is data on the lens thickness according to the height (0.2 mm interval) of the optical axis OA in the vertical direction at room temperature (about 22° C.). In detail, D_1 of FIG. 35 is the center thickness of the first lens 110 and is the thickness (mm) of the first lens 110 on the optical axis OA. Also, D_1_ET in FIG. 35 means the thickness (mm) in the optical axis (OA) direction at the end of the effective area of the first lens 110. In detail, between the end of the effective area of the object-side surface (first surface S1) of the first lens 110 and the end of the effective area of the sensor-side surface (second surface S2) of the first lens 110 means the distance (mm) in the direction of the optical axis (OA) of

Referring to FIGS. 31, 35, and 36, the thickness of the second lens 120 in the direction of the optical axis OA may decrease from the optical axis OA toward the end of the effective mirror of the second lens 120. . In detail, the thickness in the direction of the optical axis (OA) of the second lens 120 may have a maximum value along the optical axis (OA) in a range from the optical axis (OA) to the end of the effective mirror of the third surface (S3). It may have a minimum value at the end of the effective diameter of the 3 planes (S3).

Accordingly, the second lens 120 may prevent or minimize a change in optical characteristics depending on the temperature in the low to high temperature range.

The third lens 130 may be made of a plastic material and may have negative (-) refractive power on the optical axis OA. In the optical axis OA, the fifth surface S5 of the third lens 130 may have a convex shape, and the sixth surface S6 may be concave. The third lens 130 may have a meniscus shape convex from the optical axis OA toward the object side. The fifth surface S5 may be an aspheric surface (Asphere), and the sixth surface S6 may be an aspheric surface (Asphere).

36 is a vertical direction of the optical axis OA of each of the object-side surface (fifth surface S5) and sensor-side surface (sixth surface S6) of the third lens 130 at room temperature (approximately 22° C.). It is Sag data according to height (0.2mm interval).

Also, FIG. 37 is data on the lens thickness according to the height of the optical axis OA in the vertical direction at room temperature (about 22° C.). In detail, D_3 of FIG. 37 is the center thickness of the first lens 110 and is the thickness (mm) of the first lens 110 on the optical axis OA. Also, D_3_ET in FIG. 37 means the thickness (mm) in the optical axis (OA) direction at the end of the effective area of the third lens 130. In detail, between the end of the effective area of the object-side surface (fifth surface S5) of the third lens 130 and the end of the effective area of the sensor-side surface (sixth surface S6) of the third lens 130 means the distance (mm) in the direction of the optical axis (OA) of

31, 36, and 37, the thickness of the third lens 130 in the direction of the optical axis OA may increase from the optical axis OA toward the end of the effective mirror of the third lens 130. . In detail, the thickness in the direction of the optical axis (OA) of the second lens 120 is the maximum value at the end of the effective diameter of the fifth surface (S5) in the range from the optical axis (OA) to the end of the effective diameter of the fifth surface (S5). , and may have a minimum value on the optical axis OA.

Accordingly, the third lens 130 may prevent or minimize a change in optical characteristics depending on the temperature in the low to high temperature range.

In this case, the refractive power of the first lens 110 may be different from the refractive power of the second lens 120 and the third lens 130 . For example, the refractive power of the first lens 110 may be about 1.1 times greater than the refractive powers of the second lens 120 and the third lens 130 . In detail, the refractive power of the first lens 110 may be about 1.3 times or more than the refractive powers of the second lens 120 and the third lens 130 . In more detail, the refractive power of the first lens 110 may be about 1.5 times greater than the refractive powers of the second lens 120 and the third lens 130 .

Also, the refractive power of the second lens 120 may be different from the refractive power of the third lens 130 . For example, the refractive power of the third lens 130 may be about 5 times greater than the refractive power of the second lens 120 . In detail, the refractive power of the third lens 130 may be about 10 times or more than the refractive power of the second lens 120 . In more detail, the refractive power of the third lens 130 may be about 15 times or more than the refractive power of the second lens 120 .

Also, the Abbe number of the first lens 110 may be different from that of the second lens 120 and the third lens 130. For example, the Abbe number of the first lens 110 may be different from that of the second lens 120 and the third lens 130. Abbe numbers of the second lens 120 and the third lens 130 may differ within a range of 10 or less. In detail, the Abbe number of the first lens 110 may be greater than the Abbe numbers of the second lens 120 and the third lens 130 within a range of 10 or less.

In the optical system 1000 according to the second embodiment, values of aspheric coefficients of each lens surface are shown in FIG. 38 .

In addition, in the optical system 1000 according to the second embodiment, the distance (first distance) between the first lens 110 and the second lens 120 is the same as that shown in FIG. 39 at room temperature (about 22° C.), The distance (second distance) between the second lens 120 and the third lens 130 may be the same as that shown in FIG. 40 at room temperature (about 22° C.).

Referring to FIG. 39 , the first distance may decrease from the optical axis OA toward the first point L1, which is the end of the effective mirror of the second surface S2. Here, the meaning of the first point L1 is the sensor side surface (second surface S2) of the first lens 110 and the object side surface (third surface S2) of the second lens 120 facing each other. As an approximate value of the effective radius value of the second surface S2 having a smaller effective diameter among the surfaces S3), it means an approximate value of 1/2 of the effective diameter value of the second surface S2 described in Table 15.

The first interval may have a maximum value at the optical axis OA and may have a minimum value at the first point L1. The maximum value of the first interval may be about 1.1 times to about 3 times the minimum value. For example, in the first embodiment, the maximum value of the first interval may be about 1.2 times the minimum value.

Also, referring to FIG. 40 , the second distance may increase from the optical axis OA toward the second point L2, which is the end of the effective mirror of the fourth surface S4. Here, the meaning of the second point L2 is the sensor side surface (fourth surface S4) of the second lens 120 and the object side surface (fifth surface S4) of the third lens 130 facing each other. As an approximate value of the effective radius value of the fourth surface S4 having a small effective diameter among the surfaces S5), it means an approximate value of 1/2 of the effective diameter value of the fourth surface S4 described in Table 15.

The second interval may have a maximum value at the second point L2 and may have a minimum value at the optical axis OA. The maximum value of the second interval may be about 2 times to about 4 times the minimum value. For example, in the first embodiment, the maximum value of the second interval may be about 2.1 times the minimum value.

Accordingly, the optical system 1000 may have improved optical characteristics. In detail, the first lens 110, the second lens 120, and the second lens 120 and the third lens 130 are spaced according to their positions (first distance, second distance). As it is spaced apart, the optical system 1000 can prevent or minimize a change in optical characteristics in a low to high temperature range. Therefore, the optical system and the camera module according to the embodiment may maintain improved optical characteristics in various temperature ranges.

41 is a graph of relative illumination for each field of the optical system according to the second embodiment, and FIG. 42 is data on distortion characteristics of the optical system according to the second embodiment. 41 and 42 are data obtained by measuring the optical system 1000 at room temperature (about 22° C.).

Referring to FIG. 41 , the optical system 1000 according to the second embodiment may have excellent light ratio characteristics in the 0 field area (center area) to 1.0 field area (edge area) of the image sensor 300. For example, the optical system 1000 may have a peripheral light amount ratio of about 70% or more. In detail, in the optical system 1000, when the 0 field area is 100%, the light amount ratio of the 0.5 field area may be about 80% or more, and the light amount ratio of the 1.0 field area may be about 70% or more.

Also, referring to FIG. 42 , the optical system 1000 according to the second embodiment may have a barrel distortion shape in which an edge portion of an image is bent outward, and a distortion of about 2.2631% and about - It may have a TV-distortion of 0.2325%.

43 to 51 are graphs of diffraction MTF characteristics and aberration diagrams of the optical system 1000 according to temperature.

In detail, FIGS. 43 and 44 are graphs of diffraction MTF characteristics of the optical system 1000 in a low temperature (-40°C) environment, and FIGS. 46 and 47 are graphs of the optical system in a room temperature (22°C) environment. 49 and 50 are graphs of the diffraction MTF characteristics of the optical system 1000 in a high temperature (90° C.) environment.

45, 48 and 51 are graphs of aberration diagrams of the optical system 1000 in low temperature (-40°C), room temperature (22°C) and high temperature (90°C) environments, from left to right. This is a graph measuring Longitudinal Spherical Aberration, Astigmatic Field Curves, and Distortion. In FIGS. 45, 48, and 51, the X-axis may indicate a focal length (mm) or distortion (%), and the Y-axis may mean the height of an image. In addition, a graph of spherical aberration is a graph of light in a wavelength band of about 920 nm, about 940 nm, and about 960 nm, and a graph of astigmatism and distortion is a graph of light in a wavelength band of 940 nm.

In the aberration diagrams of FIGS. 45, 48, and 51, it can be interpreted that the aberration correction function is better as each curve approaches the Y-axis. Referring to FIGS. 45, 48, and 51, according to the first embodiment In the optical system 1000, it can be seen that measurement values are adjacent to the Y-axis in almost all areas.

43 to 51, in the optical system 1000 according to the second embodiment, even when the temperature is changed in the range of low temperature (-40 ° C) to high temperature (90 ° C), there is little or no change in MTF characteristics and aberration characteristics. It can be seen that it is not large. In detail, it can be seen that the change in MTF properties at low temperature (-40 °C) and high temperature (90 °C) is less than 10% of that at room temperature (22 °C).

That is, the optical system 1000 according to the second embodiment can maintain excellent optical properties in various temperature ranges. In detail, in the optical system 1000, the first lens 110 is made of a different material from the second lens 120 and the third lens 130, for example, the first lens 110 is a glass material, the second lens 120 and the third lens 130 may include a plastic material. Accordingly, when the temperature increases, the refractive index of the first lens 110 may increase, and the refractive index of the second lens 120 and the third lens 130 may decrease.

At this time, the first to third lenses 110, 120, and 130 according to the second embodiment are provided with a set refractive index, shape, thickness, etc., and the change in focal length caused by the change in refractive index that changes according to temperature is mutually can compensate Accordingly, the optical system 1000 can prevent or minimize a change in optical properties in a temperature range from low temperature (−40° C.) to high temperature (90° C.) and maintain improved optical properties.

Hereinafter, the optical system 1000 according to the third embodiment will be described in more detail with reference to FIGS. 52 to 73 .

Referring to FIG. 52, the optical system 1000 according to the third embodiment includes a first lens 110, a second lens 120, a third lens 130, and an image sequentially arranged from the object side to the sensor side. A sensor 300 may be included. The first to third lenses 110 , 120 , and 130 may be sequentially disposed along the optical axis OA of the optical system 1000 .

In addition, in the optical system 1000 according to the third embodiment, the sensor side surface (second surface S2) of the first lens 110 and the object side surface (third surface S3) of the second lens 120 ) An aperture 600 may be disposed between.

In detail, the diaphragm 600 is formed between the sensor side surface (second surface S2) of the first lens 110 and the object side surface (third surface S3) of the second lens 120. 1 may be disposed spaced apart from the sensor-side surface (second surface S2) of the lens 110.

For example, the diaphragm 600 may be spaced apart from the sensor-side surface (second surface S2) of the first lens 110 as shown in Equations 50 and 51 above.

In addition, a filter 500 may be disposed between the plurality of lenses 100 and the image sensor 300, and a cover glass 400 may be disposed between the filter 500 and the image sensor 300. It can be.

53 shows the radius of curvature of the first to third lenses 110, 120, and 130, the thickness of each lens on the optical axis OA, and the optical axis OA according to the third embodiment. ), the distance between each lens, the refractive index for light in the t-line (1013.98 nm) wavelength band, the Abbe's Number, and the size of the clear aperture (CA). Here, the lens data described in FIG. 53 is data at room temperature (about 22° C.).

Referring to FIGS. 52 and 53 , the first lens 110 of the optical system 1000 according to the third embodiment is made of glass and may have positive (+) refractive power on the optical axis OA. Also, in the optical axis OA, the first surface S1 of the first lens 110 may have a convex shape, and the second surface S2 may be concave. The first lens 110 may have a meniscus shape convex from the optical axis OA toward the object side. The first surface S1 may be a sphere, and the second surface S2 may be a sphere.

54 is a vertical direction of the optical axis OA of each of the object-side surface (first surface S1) and sensor-side surface (second surface S2) of the first lens 110 at room temperature (approximately 22° C.). It is Sag data according to height (0.2mm interval).

In addition, FIG. 55 is data on the lens thickness according to the height (0.2 mm interval) of the optical axis OA in the vertical direction at room temperature (about 22° C.). In detail, D_1 of FIG. 55 is the central thickness of the first lens 110 and is the thickness (mm) of the first lens 110 on the optical axis OA. In addition, D_1_ET in FIG. 55 means the thickness (mm) in the optical axis (OA) direction at the end of the effective area of the first lens 110. In detail, between the end of the effective area of the object-side surface (first surface S1) of the first lens 110 and the end of the effective area of the sensor-side surface (second surface S2) of the first lens 110 means the distance (mm) in the direction of the optical axis (OA) of

53 to 55 , the thickness of the first lens 110 in the direction of the optical axis OA may decrease from the optical axis OA toward the end of the effective mirror of the first lens 110. In detail, the thickness in the direction of the optical axis (OA) of the first lens 110 may have a maximum value in the optical axis (OA) in the range from the optical axis (OA) to the end of the effective mirror of the second surface (S2). It may have a minimum value at the end of the effective diameter of the second surface (S2).

Accordingly, the first lens 110 may have improved aberration control characteristics by controlling incident light.

The second lens 120 may be made of a plastic material and may have positive (+) refractive power in the optical axis OA. Also, in the optical axis OA, the third surface S3 of the second lens 120 may have a concave shape, and the fourth surface S4 may have a convex shape. The second lens 120 may have a meniscus shape convex from the optical axis OA toward the sensor. The third surface S3 may be an aspheric surface (Asphere), and the fourth surface S4 may be an aspheric surface (Asphere).

56 is a vertical direction of the optical axis OA of each of the object-side surface (third surface S3) and sensor-side surface (fourth surface S4) of the second lens 120 at room temperature (approximately 22° C.). It is Sag data according to height (0.2mm interval).

In addition, FIG. 57 is data on the lens thickness according to the height (0.2 mm interval) of the optical axis OA in the vertical direction at room temperature (about 22° C.). In detail, D_1 of FIG. 57 is the center thickness of the first lens 110 and is the thickness (mm) of the first lens 110 on the optical axis OA. In addition, D_1_ET in FIG. 57 means the thickness (mm) in the optical axis (OA) direction at the end of the effective area of the first lens 110. In detail, between the end of the effective area of the object-side surface (first surface S1) of the first lens 110 and the end of the effective area of the sensor-side surface (second surface S2) of the first lens 110 means the distance (mm) in the direction of the optical axis (OA) of

Referring to FIGS. 52, 56, and 57, the thickness of the second lens 120 in the direction of the optical axis OA may decrease from the optical axis OA toward the end of the effective mirror of the second lens 120. . In detail, the thickness in the direction of the optical axis (OA) of the second lens 120 may have a maximum value along the optical axis (OA) in a range from the optical axis (OA) to the end of the effective mirror of the third surface (S3). It may have a minimum value at the end of the effective diameter of the 3 planes (S3).

Accordingly, the second lens 120 may prevent or minimize a change in optical characteristics depending on the temperature in the low to high temperature range.

The third lens 130 may be made of a plastic material and may have negative (-) refractive power on the optical axis OA. In the optical axis OA, the fifth surface S5 of the third lens 130 may have a convex shape, and the sixth surface S6 may be concave. The third lens 130 may have a meniscus shape convex from the optical axis OA toward the object side. The fifth surface S5 may be an aspheric surface (Asphere), and the sixth surface S6 may be an aspheric surface (Asphere).

58 is a vertical direction of the optical axis OA of each of the object-side surface (fifth surface S5) and sensor-side surface (sixth surface S6) of the third lens 130 at room temperature (approximately 22° C.). It is Sag data according to height (0.2mm interval).

59 is data on the lens thickness according to the height of the optical axis OA in the vertical direction at room temperature (about 22° C.). In detail, D_3 of FIG. 37 is the central thickness of the first lens 110 and is the thickness (mm) of the first lens 110 on the optical axis OA. Also, D_3_ET in FIG. 37 means the thickness (mm) in the optical axis (OA) direction at the end of the effective area of the third lens 130. In detail, between the end of the effective area of the object-side surface (fifth surface S5) of the third lens 130 and the end of the effective area of the sensor-side surface (sixth surface S6) of the third lens 130 means the distance (mm) in the direction of the optical axis (OA) of

52, 58, and 59, the thickness of the third lens 130 in the direction of the optical axis OA may increase from the optical axis OA toward the end of the effective mirror of the third lens 130. . In detail, the thickness in the direction of the optical axis (OA) of the second lens 120 is the maximum value at the end of the effective diameter of the fifth surface (S5) in the range from the optical axis (OA) to the end of the effective diameter of the fifth surface (S5). , and may have a minimum value on the optical axis OA.

Accordingly, the third lens 130 may prevent or minimize a change in optical characteristics depending on the temperature in the low to high temperature range.

At this time, the refractive power of the first lens 110 may be different from the refractive power of the second lens 120 and the third lens 130 . For example, the refractive power of the first lens 110 may be about 1.3 times greater than the refractive powers of the second lens 120 and the third lens 130 . In detail, the refractive power of the first lens 110 may be about 1.6 times greater than the refractive powers of the second lens 120 and the third lens 130 . In more detail, the refractive power of the first lens 110 may be about 1.9 times greater than the refractive powers of the second lens 120 and the third lens 130 .

Also, the refractive power of the second lens 120 may be different from the refractive power of the third lens 130 . For example, the refractive power of the second lens 120 may be about twice or more than the refractive power of the third lens 130 . In detail, the refractive power of the second lens 120 may be about three times or more than the refractive power of the third lens 130 . In more detail, the refractive power of the second lens 120 may be about 5 times or more than the refractive power of the third lens 130 .

Also, the Abbe number of the first lens 110 may be different from that of the second lens 120 and the third lens 130. For example, the Abbe number of the first lens 110 may be different from that of the second lens 120 and the third lens 130. Abbe numbers of the second lens 120 and the third lens 130 may differ within a range of 10 or less. In detail, the Abbe number of the first lens 110 may be greater than the Abbe numbers of the second lens 120 and the third lens 130 within a range of 10 or less.

In the optical system 1000 according to the third embodiment, values of aspheric coefficients of each lens surface are shown in FIG. 60 .

In addition, in the optical system 1000 according to the third embodiment, the distance (first distance) between the first lens 110 and the second lens 120 is the same as that of FIG. 61 at room temperature (about 22° C.), and the The distance (second distance) between the second lens 120 and the third lens 130 may be the same as that shown in FIG. 62 at room temperature (about 22° C.).

Referring to FIG. 61 , the first distance may decrease from the optical axis OA toward the first point L1, which is the end of the effective mirror of the second surface S2. Here, the meaning of the first point L1 is the sensor side surface (second surface S2) of the first lens 110 and the object side surface (third surface S2) of the second lens 120 facing each other. As an approximate value of the effective radius value of the second surface S2 having a smaller effective diameter among the surfaces S3), it means an approximate value of 1/2 of the effective diameter value of the second surface S2 described in Table 15.

The first interval may have a maximum value at the optical axis OA and may have a minimum value at the first point L1. The maximum value of the first interval may be about 1.1 times to about 3 times the minimum value. For example, in the first embodiment, the maximum value of the first interval may be about 1.2 times the minimum value.

Also, referring to FIG. 62 , the second distance may increase from the optical axis OA toward the second point L2, which is the end of the effective mirror of the fourth surface S4. Here, the meaning of the second point L2 is the sensor side surface (fourth surface S4) of the second lens 120 and the object side surface (fifth surface S4) of the third lens 130 facing each other. As an approximate value of the effective radius value of the fourth surface S4 having a small effective diameter among the surfaces S5), it means an approximate value of 1/2 of the effective diameter value of the fourth surface S4 described in Table 15.

The second interval may have a maximum value at the second point L2 and may have a minimum value at the optical axis OA. The maximum value of the second interval may be about 2 times to about 4 times the minimum value. For example, in the first embodiment, the maximum value of the second interval may be about 2.1 times the minimum value.

Accordingly, the optical system 1000 may have improved optical characteristics. In detail, the first lens 110, the second lens 120, and the second lens 120 and the third lens 130 are spaced according to their positions (first distance, second distance). As it is spaced apart, the optical system 1000 can prevent or minimize a change in optical characteristics in a low to high temperature range. Therefore, the optical system and the camera module according to the embodiment may maintain improved optical characteristics in various temperature ranges.

63 is a graph of relative illumination for each field of the optical system according to the third embodiment, and FIG. 64 is data on distortion characteristics of the optical system according to the third embodiment. 63 and 64 are data obtained by measuring the optical system 1000 at room temperature (about 22° C.).

Referring to FIG. 63 , the optical system 1000 according to the third embodiment may have excellent light quantity ratio characteristics in the 0 field area (center area) to 1.0 field area (edge area) of the image sensor 300 . For example, the optical system 1000 may have a peripheral light amount ratio of about 70% or more. In detail, in the optical system 1000, when the 0 field area is 100%, the light amount ratio of the 0.5 field area may be about 80% or more, and the light amount ratio of the 1.0 field area may be about 70% or more.

Also, referring to FIG. 64 , the optical system 1000 according to the third embodiment may have a barrel distortion shape in which an edge portion of an image is bent outward, and a distortion of about 0.7615% and about - It can have a TV-distortion of 0.9947%.

65 to 73 are graphs of diffraction MTF characteristics and aberration diagrams of the optical system 1000 according to temperature.

In detail, FIGS. 65 and 66 are graphs of diffraction MTF characteristics of the optical system 1000 in a low temperature (-40°C) environment, and FIGS. 68 and 69 are graphs of the optical system in a room temperature (22°C) environment. 71 and 72 are graphs of the diffraction MTF characteristics of the optical system 1000 in a high temperature (90° C.) environment.

67, 70, and 73 are graphs of aberration diagrams of the optical system 1000 in low temperature (-40°C), room temperature (22°C), and high temperature (90°C) environments, from left to right. This is a graph measuring Longitudinal Spherical Aberration, Astigmatic Field Curves, and Distortion. In FIGS. 67, 70, and 73, the X-axis may indicate a focal length (mm) or distortion (%), and the Y-axis may indicate the height of an image. In addition, a graph of spherical aberration is a graph of light in a wavelength band of about 920 nm, about 940 nm, and about 960 nm, and a graph of astigmatism and distortion is a graph of light in a wavelength band of 940 nm.

In the aberration diagrams of FIGS. 67, 70, and 73, it can be interpreted that the aberration correction function is better as each curve approaches the Y-axis. Referring to FIGS. 67, 70, and 73, according to the first embodiment In the optical system 1000, it can be seen that measurement values are adjacent to the Y-axis in almost all regions.

65 to 73, in the optical system 1000 according to the third embodiment, even when the temperature is changed in the range of low temperature (-40 ° C) to high temperature (90 ° C), there is little or no change in MTF characteristics and aberration characteristics. It can be seen that it is not large. In detail, it can be seen that the change in MTF properties at low temperature (-40 °C) and high temperature (90 °C) is less than 10% of that at room temperature (22 °C).

That is, the optical system 1000 according to the third embodiment can maintain excellent optical properties in various temperature ranges. In detail, in the optical system 1000, the first lens 110 is made of a different material from the second lens 120 and the third lens 130, for example, the first lens 110 is a glass material, the second lens 120 and the third lens 130 may include a plastic material. Accordingly, when the temperature increases, the refractive index of the first lens 110 may increase, and the refractive index of the second lens 120 and the third lens 130 may decrease.

At this time, the first to third lenses 110, 120, and 130 according to the third embodiment are provided with a set refractive index, shape, thickness, etc., so that the change in focal length caused by the change in refractive index that changes according to temperature is mutually can compensate Accordingly, the optical system 1000 can prevent or minimize a change in optical properties in a temperature range from low temperature (−40° C.) to high temperature (90° C.) and maintain improved optical properties.

Features, structures, effects, etc. described in the embodiments above are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, and effects illustrated in each embodiment can be combined or modified with respect to other embodiments by those skilled in the art in the field to which the embodiments belong. Therefore, contents related to these combinations and variations should be construed as being included in the scope of the present invention.

In addition, although the above has been described with a focus on the embodiments, these are only examples and do not limit the present invention, and those skilled in the art to which the present invention belongs can exemplify the above to the extent that does not deviate from the essential characteristics of the present embodiment. It will be seen that various variations and applications that have not been made are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

Claims (14)

An optical system including first to third lenses disposed along an optical axis from an object side to a sensor side,
The optical system,
Satisfies 40 degree ≤ FOV ≤ 50 degree,
The object-side surface and the sensor-side surface of the first lens are spherical,
The first lens has a meniscus shape convex toward the object side,
The first lens, the second lens and the third lens,
Satisfy 1.7 ≤ nt_1 ≤ 2.3,
1.2mm ≤ D_1 ≤ 2.2mm
0.15 ≤ D_1/TTL ≤ 0.35
1.5 < D_1 / D_2 < 2.5
Satisfy 3.0 < D_1 / D_3 < 4.0,
Optical system for infrared cameras that satisfies TTL ≤ 9mm.
(nt_1 is the refractive index of the first lens, TTL is the distance on the optical axis from the object side surface of the first lens to the top surface of the image sensor, D_1 is the thickness of the first lens on the optical axis, and FOV is the It means the angle of view (FOV) of the optical system.) According to claim 1,
The optical system for an infrared camera, wherein the first lens thickness satisfies the following condition.
1.2mm ≤ D_1 ≤ 2.2mm According to claim 1,
An optical system for an infrared camera further including an infrared pass filter. According to claim 1,
Further comprising an aperture disposed between the first lens and the second lens,
The aperture,
An optical system for an infrared camera that satisfies 0 < d1Ap < 0.2.
(d1Ap means the distance (mm) in the optical axis direction of the diaphragm from the tip of the effective mirror of the first lens.) According to claim 4,
The first lens and the diaphragm,
An optical system for an infrared camera that satisfies 0.8 < CA_L1S2 / CA_Ap < 1.8.
(CA_L1S2 means the size (mm) of the effective diameter of the sensor side of the first lens, and CA_Ap means the size (mm) of the effective diameter of the diaphragm.) According to claim 1,
The first lens, the second lens and the third lens,
0.3 < |f1 / f2| < 1.2
1 < |f3 / f1| Optical system for infrared cameras that satisfies < 10.
(f1 is the focal length of the first lens (mm), f2 is the focal length of the second lens (mm), and f3 is the focal length of the third lens (mm).) According to claim 1,
The second lens,
1.0 < |L2R1| / |L2R2| Optical system for infrared cameras that satisfies < 2.0.
(L2R1 is the radius of curvature of the object-side surface of the second lens, and L2R2 is the radius of curvature of the sensor-side surface of the second lens.) According to claim 1,
The third lens,
1.1 < |L3R1| / |L3R2| Optical system for infrared cameras that satisfies < 1.5.
(L3R1 is the radius of curvature of the object-side surface of the third lens, and L3R2 is the radius of curvature of the sensor-side surface of the third lens.) According to claim 1,
The first lens and the second lens,
An optical system for an infrared camera that satisfies 0.2 < d12 / D_1 < 0.9.
(d12 is the distance (mm) between the first lens and the second lens on the optical axis (OA), and D_1 is the thickness (mm) on the optical axis of the first lens.) According to claim 1,
The first lens and the second lens have positive (+) refractive power,
The optical system for an infrared camera wherein the third lens has negative (-) refractive power. An optical system including first to third lenses disposed along an optical axis from an object side to a sensor side,
The first lens and the second lens have positive (+) refractive power,
The third lens has negative (-) refractive power,
The first lens has a meniscus shape convex toward the object side,
The first lens, the second lens and the third lens,
1.2mm ≤ D_1 ≤ 2.2mm
0.15 ≤ D_1/TTL ≤ 0.35
1.5 < D_1 / D_2 < 2.5
Satisfy 3.0 < D_1 / D_3 < 4.0,
satisfies TTL ≤ 9 mm,
The optical system,
The change rate of the effective focal length at high temperature compared to room temperature is 0% to 10%,
An optical system in which the change rate of the angle of view at a high temperature compared to room temperature is 0% to 10%.
(Room temperature is 20 ° C to 30 ° C, high temperature is 80 ° C to 90 ° C.) According to claim 11,
The first lens to the third lens
dnt_1/dt ≥ 0;
dnt_2/dt <0;
An optical system that satisfies dnt_3/dt < 0.
(dnt_1/dt is the change in refractive index of the first lens according to temperature change, dnt_2/dt is the change in refractive index of the second lens according to temperature change, and dnt_3/dt is the change in refractive index of the third lens according to temperature change .) According to claim 12,
The first lens and the second lens,
|dnt_2/dt| / |dnt_1/dt| > Optics satisfying 20.
(|dnt_2/dt| is the refractive index change of the second lens in the d-line of 20 to 40 degrees, and |dnt_1/dt| is the refractive index change of the first lens in the d-line of 20 to 40 degrees.) According to claim 12,
The optical system of claim 1, wherein the sum of the Abbe numbers of the first lens, the second lens, and the third lens is 50 or more and 70 or less.

Images