Patent Publication Number: US-2022221682-A1

Title: Lens assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 U.S.C. § 119(a) of Korean Patent Application No. 10-2021-0002470 filed on Jan. 8, 2021 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. 
     BACKGROUND 
     1. Field 
     The present disclosure relates to a lens assembly, and more particularly, to a spacer disposed between neighboring lenses. 
     2. Description of Related Art 
     An image capturing device, which is a device for taking a picture or an image of a subject such as a person, an object, or a landscape, may acquire data from light incident on the image capturing device, and store the data as a file in a storage medium and/or display the image on a display unit. 
     The image capturing device may include a lens barrel including a plurality of lenses configured to capture an image of a subject. In order to maintain a space between lenses among the plurality of lenses, a lens spacer may be disposed between the lenses. 
     The lens spacer may vary in terms of material and formation method, depending on the space between the lenses. For example, when the space between the lenses is relatively large, a block-type lens spacer manufactured of a metal or a hard material through a machining process, such as a cutting process, may be used. On the other hand, when the space between the lenses is relatively small, a film-type lens spacer manufactured in a form of a thin film or plate through a pressing process may be used. 
     The spacer may be deformed depending on surrounding environments (e.g., temperature and humidity). When the spacer has an asymmetric shape (e.g., a D-cut shape), the spacer may be deformed to a greater degree according to the change in the surrounding environments. In this case, two lenses respectively disposed on opposite sides of the spacer may be minutely misaligned, resulting in a negative influence on image quality. 
     SUMMARY 
     This Summary is provided to introduce a selection of concepts in simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     In one general aspect, a lens assembly includes: a lens barrel; lenses accommodated in the lens barrel; and a spacer disposed between neighboring lenses among the lenses, and having an incident hole. An inner side surface of the spacer surrounding the incident hole includes a first inner side surface and a second inner side surface facing each other, and a third inner side surface and a fourth inner side surface facing each other. Each of the first inner side surface, the second inner side surface, the third inner side surface, and the fourth inner side surface includes a concavely curved surface facing a center of the spacer. The first inner side surface, the second inner side surface, the third inner side surface, and the fourth inner side surface have radii of curvature R 1 , R 2 , R 3 , and R 4 , respectively. The lens assembly satisfies the expressions: R 1 =R 2 ; R 3 ≠R 1 ; and R 4 ≠R 1 . 
     The lens assembly may satisfy the expressions: R 1 &lt;R 3 ; and R 1 &lt;R 4 . 
     The lens assembly may satisfy the expressions: 0.12&lt;R 1 /R 3 &lt;0.50; and R 3 =R 4 . 
     The lens assembly may satisfy the following expressions: 0.12&lt;R 1 /R 3 &lt;0.50; 0.12&lt;R 1 /R 4 &lt;0.50; and R 3 ≠R 4 . 
     The spacer may include a corrugated portion formed along the inner side surface. A distance between the corrugated portion and a center of curvature of the inner side surface may repeatedly increase and decrease locally along the inner side surface. 
     The corrugated portion may include a first corrugated portion formed on the first inner side surface. The lens assembly may satisfy the expressions: 50&lt;R 1 /R 5 &lt;400; and R 1 &lt;R 3 , wherein R 5  is a radius of a valley portion or a ridge portion in the first corrugated portion. 
     The corrugated portion may include a third corrugated portion formed on the third inner side surface. The lens assembly may satisfy the expressions: 10&lt;R 3 /R 7 &lt;70; and R 1 &lt;R 3 , wherein R 7  is a radius of a valley portion or a ridge portion in the third corrugated portion. 
     The corrugated portion may be formed along an entirety of the inner side surface. 
     The spacer may include a cutout portion connecting an outer side surface of the spacer to the inner side surface. 
     The spacer may include straight line portions facing each other and curved line portions facing each other. The cutout portion may be formed in one of the curved line portions. 
     The inner side surface and the outer side surface may each have a D-cut shape. 
     The inner side surface may have a circular shape. The outer side surface may have a D-cut shape. 
     The inner side surface and the outer side surface may each have a circular shape. 
     The lens cutout portion may have a width of 0.05 mm to 0.5 mm. 
     The spacer may have a thickness of 0.01 mm to 0.5 mm. 
     The spacer may have a thickness of 0.01 mm to 0.5 mm. 
     A width of the cutout portion at an upper surface of the spacer may be different from a width of the cutout portion at a lower surface of the spacer. 
     Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a lens assembly, according to an embodiment. 
         FIG. 2  is a plan view of a spacer, according to an embodiment. 
         FIG. 3  is a plan view of a spacer, according to another embodiment. 
         FIG. 4  is a plan view of a spacer, according to another embodiment. 
         FIG. 5  is a plan view of a spacer, according to another embodiment. 
         FIG. 6  is a perspective view of a spacer, according to another embodiment. 
         FIG. 7  is a plan view of a spacer, according to another embodiment. 
         FIG. 8  is a plan view of a spacer, according to another embodiment. 
         FIG. 9  is a plan view of a spacer, according to another embodiment. 
         FIG. 10  is a plan view of a spacer, according to another embodiment. 
     
    
    
     Throughout the drawings and the detailed description, the same reference numerals refer to the same elements. The drawings may not be to scale, and the relative sizes, proportions, and depictions of elements in the drawings may be exaggerated for clarity, illustration, and convenience. 
     DETAILED DESCRIPTION 
     The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be apparent after an understanding of this disclosure. For example, the sequences of operations described herein are merely examples, and are not limited to those set forth herein, but may be changed as will be apparent after an understanding of this disclosure, with the exception of operations necessarily occurring in a certain order. Also, descriptions of features that are known in the art may be omitted for increased clarity and conciseness. 
     The features described herein may be embodied in different forms, and are not to be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways of implementing the methods, apparatuses, and/or systems described herein that will be apparent after an understanding of this disclosure. Hereinafter, while embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, it is noted that examples are not limited to the same. 
     Throughout the specification, when an element, such as a layer, region, or substrate, is described as being “on,” “connected to,” or “coupled to” another element, it may be directly “on,” “connected to,” or “coupled to” the other element, or there may be one or more other elements intervening therebetween. In contrast, when an element is described as being “directly on,” “directly connected to,” or “directly coupled to” another element, there can be no other elements intervening therebetween. As used herein “portion” of an element may include the whole element or less than the whole element. 
     As used herein, the term “and/or” includes any one and any combination of any two or more of the associated listed items; likewise, “at least one of” includes any one and any combination of any two or more of the associated listed items. 
     Although terms such as “first,” “second,” and “third” may be used herein to describe various members, components, regions, layers, or sections, these members, components, regions, layers, or sections are not to be limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer, or section from another member, component, region, layer, or section. Thus, a first member, component, region, layer, or section referred to in examples described herein may also be referred to as a second member, component, region, layer, or section without departing from the teachings of the examples. 
     Spatially relative terms, such as “above,” “upper,” “below,” “lower,” and the like, may be used herein for ease of description to describe one element&#39;s relationship to another element as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, an element described as being “above,” or “upper” relative to another element would then be “below,” or “lower” relative to the other element. Thus, the term “above” encompasses both the above and below orientations depending on the spatial orientation of the device. The device may also be oriented in other ways (rotated 90 degrees or at other orientations), and the spatially relative terms used herein are to be interpreted accordingly. 
     The terminology used herein is for describing various examples only, and is not to be used to limit the disclosure. The articles “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “includes,” and “has” specify the presence of stated features, numbers, operations, members, elements, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, members, elements, and/or combinations thereof. 
     Due to manufacturing techniques and/or tolerances, variations of the shapes shown in the drawings may occur. Thus, the examples described herein are not limited to the specific shapes shown in the drawings, but include changes in shape that occur during manufacturing. 
     The features of the examples described herein may be combined in various ways as will be apparent after an understanding of this disclosure. Further, although the examples described herein have a variety of configurations, other configurations are possible as will be apparent after an understanding of this disclosure. 
     Herein, it is noted that use of the term “may” with respect to an example, for example, as to what an example may include or implement, means that at least one example exists in which such a feature is included or implemented while all examples are not limited thereto. 
       FIG. 1  is a perspective view of a lens assembly  1 , according to an embodiment. 
     The lens assembly  1  may include lenses  101  and  102  and a lens barrel  200  accommodating the lenses  101  and  102  such that the lenses  101  and  102  are disposed adjacent to each other in an optical axis direction. In an example, the lens assembly  1  may include a spacer  300  disposed between the lenses  101  and  102 . The spacer  300  may be configured to maintain a constant space between the two neighboring lenses  101  and  102 . In designing an optical system, the space between the lenses  101  and  102  acts as a major factor affecting image quality. Through the spacer  300 , the lenses  101  and  102  may be spaced apart from each other on opposite sides of the spacer  300  to have a predetermined space therebetween. 
     In an example, the spacer  300  may include an incident hole inside the spacer  300 , and light may pass through the incident hole between the first lens  101  and the second lens  102 . 
     In addition, the spacer  300  may be configured to partially block the light having passed through one lens  101 . For example, the spacer  300  may partially block the light having passed through a periphery of the first lens  101 . By partially blocking the light, the spacer  300  may prevent or minimize a flare phenomenon. 
     In an example, the spacer  300  may be manufactured of a plastic or metal material. For example, the spacer  300  may be manufactured of a polyethylene terephthalate (PET) or metal material having a thickness of about 0.01 mm to 0.1 mm. In another example, the spacer  300  may be manufactured of a plastic material having a thickness of about 0.1 mm to 0.5 mm. 
     Hereinafter, various spacers provided between the lenses  101  and  102  will be described with reference to  FIGS. 2 through 10 . Each of the spacers to be described below may be applied to any optical system in which the two neighboring lenses  101  and  102  are included, and is not limited to that applied to the lens assembly  1  illustrated in  FIG. 1 . 
       FIG. 2  is a plan view of the spacer  300 , according to an embodiment.  FIG. 3  is a plan view of a spacer  300 - 1 , according to another embodiment.  FIG. 4  is a plan view of a spacer  300 - 2 , according to another embodiment.  FIG. 5  is a plan view of a spacer  300 - 3 , according to another embodiment.  FIG. 6  is a perspective view of a spacer  300 - 4 , according to another embodiment. 
     Referring to  FIG. 2 , the spacer  300  may have a ring shape extending along edge portions of lenses (e.g., the lenses  101  and  102  in  FIG. 1 ). The spacer  300  may include a cutout portion  301 . For example, the spacer  300  may have a “C” shape. Two ends  302  and  303  of the spacer  300  may face each other with the cutout portion  301  interposed therebetween. A space between both ends  302  and  303  of the spacer  300  (that is, a width W of the cutout portion  301 ) may be formed to be relatively narrow, so that no negative influence is caused in maintaining the space between the lenses  101  and  102 , which are disposed on an upper surface  304  and a lower surface  305  of the spacer  300 , respectively. For example, the width W of the cutout portion  301  of the spacer  300  may have a smaller value than an overall width of the spacer  300 . 
     In an example, the spacer  300  may be manufactured of a polyethylene terephthalate (PET) or metal material having a thickness of about 0.01 mm to 0.1 mm. In this case, the width W of the cutout portion  301  may have a value between about 0.05 mm and about 0.5 mm. In another example, the spacer  300  may be manufactured of a plastic material having a thickness between about 0.1 mm and about 0.5 mm. In this case, the width W of the cutout portion  301  may have a value between about 0.1 mm and about 0.5 mm. 
     In an embodiment, the spacer  300  may include the upper surface  304 , the lower surface  305 , and a side surface  306  extending from the upper surface  304  to the lower surface  305 . The side surface  306  may include an inner side surface  307  facing the center of the spacer  300  and an outer side surface  308  facing outside the spacer  300 . The inner side surface  307  of the spacer  300  may at least partially surround the incident hole inside the spacer  300 . 
     Referring to  FIG. 2 , the inner side surface  307  and the outer side surface  308  may be connected to each other through the cutout portion  301 . For example, the inner side surface  307  and the outer side surface  308  may be connected to each other through the cutout portion  301  such that a single closed curve is formed. 
     The spacer  300  may be deformed depending on surrounding environmental conditions (e.g., temperature and humidity). When the spacer  300  has an asymmetric shape, the spacer  300  may be deformed to a greater degree according to the change in the surrounding environmental conditions. In this case, the two lenses  101  and  102  disposed on both sides of the spacer  300  may be minutely misaligned, resulting in a negative influence on image quality. 
     As described above, the spacer  300  may include the cutout portion  301 , which may minimize a degree of deformation of the spacer  300 . The cutout portion  301  may minimize or prevent misalignment between the lenses  101  and  102  on both sides of the spacer  300 , and improve the performance of the optical system including the spacer  300 . 
     In an example, the spacer  300  may have a D-cut shape. For example, the spacer  300  may include two straight line portions  310  facing each other in parallel and two curved line portions  309  facing each other. Each of the curved line portions  309  may have an arc shape. For example, the curved line portions  309  may have a shape of a pair of parentheses (i.e., “( )”). Each of the straight line portions  310  may be a portion extending in a straight line shape or in an approximately straight line shape. 
     Referring to  FIG. 2 , in an example, both the inner side surface  307  and the outer side surface  308  of the spacer  300  may have a D-cut shape. A first inner side surface  307   a  and a first outer side surface  308   a  may define one curved line portion  309   a  of the D-cut shape, and a second inner side surface  307   b  and a second outer side surface  308   b  may define the other curved line portion  309   b  of the D-cut shape. Also, a third inner side surface  307   c  and a third outer side surface  308   c  may define one straight line portion  310   a  of the D-cut shape, and a fourth inner side surface  307   d  and a fourth outer side surface  308   d  may define the other straight line portion  310   b  of the D-cut shape. 
     In an example, at least one of the inner side surface  307  and the outer side surface  308  of the spacer  300  may have a D-cut shape. 
     Referring to  FIG. 3 , a spacer  300 - 1 , according to an embodiment, may include an inner side surface  307 - 1  and an outer side surface  308 - 1  both having a circular shape. Referring to  FIG. 4 , a spacer  300 - 2 , according to an embodiment, may include an inner side surface  307 - 1  having a circular shape and the outer side surface  308  having a D-cut shape. Referring to  FIG. 5 , a spacer  300 - 3 , according to an embodiment, may include the inner side surface  307  having a D-cut shape and the outer side surface  308 - 1  having a circular shape. 
     In an example, the cutout portion  301  may be formed in one of the curved line portions (e.g., the curved line portion  309  in  FIG. 1 , and the curved-line portions in  FIGS. 2 to 5 ). That is, referring to  FIG. 2 , the cutout portion  301  may be provided by cutting out the curved line portion  309   a  or  309   b  of the D-cut shape. For example, referring to  FIG. 2 , the first inner side surface  307   a  and the first outer side surface  308   a  may define one curved line portion  309   a  of the D-cut shape, and the cutout portion  301  may connect a center portion of the first inner side surface  307   a  and a center portion of the first outer side surface  308   a  to each other. 
     However, the position of the cutout portion  301  is not limited to that in the embodiments illustrated in  FIGS. 2 through 5 . For example, the cutout portion  301  illustrated in  FIG. 2  may be formed by cutting out a portion surrounded by the third inner side surface  307   c  and the third outer side surface  308   c.    
     In an example, the width of the cutout portion  301  may be determined so that both ends  302  and  303  of the cutout portion  301  do not contact each other even when the spacer  300  is thermally expanded. For example, the width of the cutout portion  301  may be in the range of 0.05 mm to 0.5 mm. 
     Referring to  FIG. 6 , in an embodiment, a cutout portion  301 - 4  of a spacer  300 - 4  may vary in a thickness direction. For example, referring to  FIG. 6 , the upper surface  304  and a lower surface  305 - 4  of the spacer  300 - 4  may have different shapes, and the width W 1  of the cutout portion  301 - 4  at the upper surface  304  may be different than a width W 2  of the cutout portion  301 - 4  at the lower surface  305  (W 1 ≠W 2 ). For example, a width of the cutout portion  301 - 4  may progressively change from the width W 1  to the width W 2  between the upper surface  304  and the lower surface  305 . 
       FIG. 7  is a plan view of a spacer  300 - 5 , according to another embodiment.  FIG. 8  is a plan view of a spacer  300 - 6 , according to another embodiment.  FIG. 9  is a plan view of a spacer  300 - 7 , according to another embodiment.  FIG. 10  is a plan view of a spacer  300 - 8 , according to another embodiment. 
     Referring to  FIG. 7 , in an embodiment, an inner side surface  307 - 5  of the spacer  300 - 5  may be formed as an entirely curved surface. For example, each of a first inner side surface  307   a - 5 , a second inner side surface  307   b - 5 , a third inner side surface  307   c - 5 , and a fourth inner side surface  307   d - 5  may have an arc shape. For example, the first inner side surface  307   a - 5 , the second inner side surface  307   b - 5 , the third inner side surface  307   c - 5 , and the fourth inner side surface  307   d - 5  may have a first radius R 1 , a second radius R 2 , a third radius R 3 , and a fourth radius R 4 , respectively. 
     In an example, the inner side surface  307 - 5  may have a concave shape when viewed from the center of the spacer  300 - 5 . In an example, the center of curvature of the inner side surface  307 - 5  of the spacer  300 - 5  may be located in a direction that the inner side surface  307 - 5  faces. For example, the center of curvature of the first inner side surface  307   a - 5  may be located in direction −Y with respect to the first inner side surface  307   a - 5 . The center of curvature of the second inner side surface  307   b - 5  may be located in direction +Y with respect to the second inner side surface  307   b - 5 . The center of curvature of the third inner side surface  307   c - 5  may be located in direction +X with respect to the third inner side surface  307   c - 5 . The center of curvature of the fourth inner side surface  307   d - 5  may be located in direction −X with respect to the fourth inner side surface  307   d - 5 . 
     In an example, the radii of curvature (hereinafter, referred to as “radii”) of the inner side surfaces  307   a - 5 ,  307   b - 5 ,  307   c - 5 , and  307   d - 5  may be the same or different. In an example, the inner side surfaces  307   a - 5  and  307   b - 5  or  307   c - 5  and  307   d - 5  facing each other may have the same radius. For example, the first radius R 1  may be the same as the second radius R 2 , and the third radius R 3  may be the same as the fourth radius R 4 . In another example, the inner side surfaces facing each other may have different radii. For example, the first radius R 1  may be the same as the second radius R 2 , but the third radius R 3  may be different from the fourth radius R 4 . 
     In an example, the spacer  300 - 5  may have a D-cut shape. In The outer side surface  308 - 5  of the spacer  300  may include the two straight line portions  310   a  and  310   b  facing each other in parallel and two curved line portions  309   a - 5  and  309   b  facing each other. In an example, the radius of the inner side surface (e.g., the third inner side surface  307   c - 5  or the fourth inner side surface  307   d - 5 ) corresponding to the straight line portion  310   a  or  310   b  may be greater than that of the inner side surface (e.g., the first inner side surface  307   a - 5  or the second inner side surface  307   b - 5 ) corresponding to the curved line portion  309   a  or  309   b.  For example, the first inner side surface  307   a  and the second inner side surface  307   b  may correspond to the curved line portions  309   a - 5  and  309   b  of the D-cut shape and have the first radius R 1  and the second radius R 2 , respectively. Also, the third inner side surface  307   c - 5  and the fourth inner side surface  307   d - 5  may correspond to the straight line portions  310   a  and  310   b  of the D-cut shape and have the third radius R 3  and the fourth radius R 4 , respectively. In this case, the third radius R 3  and the fourth radius R 4  may be greater than the first radius R 1  or the second radius R 2 . That is, the third inner side surface  307 - 5   c  and the fourth inner side surface  307   d - 5  may have curved surfaces flatter than those of the first inner side surface  307   a - 5  or the second inner side surface  307   b - 5 . In this case, the following Conditional Expression (1) may be satisfied between the first inner side surface  307   a - 5  (or the second inner side surface  307   b ) and the third inner side surface  307   c - 5  (or the fourth inner side surface  307   d - 5 ) neighboring to each other. 
       0.12&lt; R 1(or  R 2)/ R 3(or  R 4)&lt;0.50   Conditional Expression (1)
 
     The spacer  300 - 5  may include the concave inner side surface  307 - 5  to prevent or minimize a flare phenomenon caused by light reflected from the inner side surface  307 - 5  of the spacer  300 - 5 . In addition, an optical system including the spacer  300 - 5  with the concave inner side surface  307 - 5  may have a sufficient opening area to achieve a higher f-number (fno), as compared with that when an inner side surface of a spacer is flat or convex. 
     Referring to  FIG. 8 , in an embodiment, the spacer  300 - 6  may include a corrugated portion  311  at least partially formed on an inner side surface  307 - 6 . In the illustrated embodiment, inner side surfaces  307   a - 6 ,  307   b - 6 ,  307   c - 6 , and  307   d - 6  may include corrugated portions  311   a,    311   b,    311   c  and  311   d,  respectively. 
     In the embodiment of  FIG. 7 , a distance between the first inner side surface  307   a - 5  and the center of curvature of the first inner side surface  307   a - 5  is constant as the first radius R 1 . In contrast, referring to  FIG. 8 , when measuring a distance between the first inner side surface  307   a - 6  and the center of curvature thereof in a circumferential direction, the distance may repeatedly increase and decrease within a predetermined range based on the first radius R 1  because of the first corrugated portion  311   a.  In an example, a distance between the corrugated portion  311  and the center of curvature of the inner side surface  307 - 6  on which the corrugated portion  311  is located may repeatedly increase and decrease locally along the inner side surface  307 - 6 . In an example, the corrugated portion  311  may be defined by alternately arranging a plurality of valleys and a plurality of ridges. In this case, the distance between the inner side surface  307 - 6  and the center of curvature thereof may be greatest at the valleys and smallest at the ridges. 
     In the embodiment illustrated in  FIG. 8 , the corrugated portion  311  is present entirely on the inner side surface  307 - 6  of the spacer  300 - 6 . However, in another embodiment, the corrugated portion  311  may be included only partially on the inner side surface  307 - 6 . For example, the third inner side surface  307   c - 6  and the fourth inner side surface  307   d - 6  may include a third corrugated portion  311   c  and a fourth corrugated portion  311   d,  respectively, and the corrugated portions  311   a  and  311   b  may be omitted on the first inner side surface  307   a - 6  and the second inner side surface  307   b - 6 . 
     In an embodiment, the corrugated portion  311  may have an arc shape. Referring to  FIG. 8 , valley portions (or ridge portions) of the corrugated portions  311   a  and  311   b  constituting the first inner side surface  307   a - 6  and the second inner side surface  307   b - 6  may have a fifth radius R 5  and a sixth radius R 6 , respectively. Also, valley portions (or ridge portions) of the corrugated portions  311   c  and  311   d  constituting the third inner side surface  307   c - 6  and the fourth inner side surface  307   d - 6  may have a seventh radius R 7  and an eighth radius R 8 , respectively. 
     In an embodiment, the corrugated portions  311   a  and  311   b  or  311   c  and  311   d  formed on the inner side surfaces  307   a - 6  and  307   b - 6  or  307   c - 6  and  307   d - 6  facing each other may have the same radius. For example, the fifth radius R 5  and the sixth radius R 6  may conform to each other, and the seventh radius R 7  and the eighth radius R 8  may conform to each other. 
     In an embodiment, each of the valley portions and the ridge portions of the corrugated portion  311  may have a radius smaller than the radius of the inner side surface  307 - 6  on which the corrugated portion  311  is located. In an embodiment, the inner side surfaces  307   a - 6 ,  307   b - 6 ,  307   c - 6 , and  307   d - 6  may be configured to satisfy the following Conditional Expression (2) and/or the following Conditional Expression (3). For example, the first radius R 1  (or the second radius R 2 ) and the fifth radius R 5  (or the sixth radius R 6 ) may satisfy the following Conditional Expression (2), and the third radius R 3  (or the fourth radius R 4 ) and the seventh radius R 7  (or the eighth radius R 8 ) may satisfy the following Conditional Expression (3). 
       50&lt; R 1(or  R 2)/ R 5(or  R 6)&lt;400, where  R 1&lt; R 3   Conditional Expression (2)
 
       10&lt; R 3(or  R 4)/ R 7(or  R 8)&lt;70, where  R 1&lt; R 3   Conditional Expression (3)
 
     Referring to  FIGS. 9 and 10 , the spacers  300 - 7  and  300 - 8 , which are similar to the spacers  300 - 5  and  300 - 6 , respectively, illustrated in  FIG. 7  and  FIG. 8 , may further include a cutout portion  301 . The cutout portion  301  of  FIGS. 9 and 10  may be configured to be identical or similar to those described in  FIGS. 2 through 6 . 
     Referring to  FIG. 9 , in an embodiment, all of a first inner side surface  307   a - 5  to the fourth inner side surface  307   d - 5  constituting an inner side surface  307 - 7 of the spacer  300  may have concavely curved surfaces when viewed from the center of the spacer  300 - 7 , and a portion of a first inner side surface  307   a - 5  may be connected to an outer side surface  308 - 7  through the cutout portion  301 . 
     Referring to  FIG. 10 , in an embodiment, all of a first inner side surface  307   a - 8  to the fourth inner side surface  307   d - 6  constituting an inner side surface  307 - 8  of the spacer  300 - 8  may have concavely curved surfaces when viewed from the center of the spacer  300 - 8 , the inner side surface  307 - 8  may at least partially include a corrugated portion  311 - 8 , and a portion of the first inner side surface  307   a - 8  may be connected to the outer side surface  308 - 7  through the cutout portion  301 . 
     The corrugated portion  311 - 8  included in the spacer  300 - 8  may prevent or minimize a flare phenomenon caused by light reflected from the inner side surface  307 - 8  of the spacer  300 - 8 . 
     Embodiments of the disclosure herein are not limited to those illustrated in  FIGS. 2 through 10 . Although not explicitly described in this disclosure, an embodiment including some or all of the features of the spacers  300  to  300 - 8  described herein may also fall within the scope of the disclosure. For example, if the embodiment of  FIG. 4  and the embodiment of  FIG. 8 , in which the circular inner side surface  307 - 1  and the corrugated portion  311  are included as their features respectively, are combined together, the spacer may include a circular inner side surface and a corrugated portion provided on the inner side surface. 
     As set forth above, according to embodiments disclosed herein, a spacer and a lens assembly including the spacer may be capable of stably maintaining a space between neighboring lenses and preventing a deterioration in image quality. 
     While this disclosure includes specific examples, it will be apparent after an understanding of the disclosure of this application that various changes in form and details may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered in a descriptive sense only, and not for purposes of limitation. Descriptions of features or aspects in each example are to be considered as being applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques are performed in a different order, and/or if components in a described system, architecture, device, or circuit are combined in a different manner, and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.