Patent Publication Number: US-2016223776-A1

Title: Lens module

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit of Korean Patent Application No. 10-2015-0016011 filed on Feb. 2, 2015 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. 
     BACKGROUND 
     1. Field 
     The following description relates to a lens module. 
     2. Description of Related Art 
     A lens barrel accommodating lenses is provided in a lens module used for a camera. The lenses are inserted into the lens barrel and are fixed thereto. In a case in which the lenses are closely adhered to each other without gaps, or the lenses and the lens barrel are closely adhered to each other without a gap, the lenses are attached in a state in which air is confined therebetween. 
     It is undesirable for the air confined between the lenses to contract or expand depending on temperature changes within a surrounding environment, since an attachment position of the lenses may be changed by the contraction or expansion of the air confined between the lenses. 
     In addition, it is undesirable for the air confined between the lenses to become liquefied due to a condensation phenomenon, since the performance of the camera module may be deteriorated by condensation between the lenses. Therefore, it is required that the air confined between the lenses be circulated externally. 
     SUMMARY 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     According to one general aspect, a lens module includes: a first lens including a concave part and a first outer horizontal surface extended from an outer side of the concave part; a second lens including a convex part coupled to the concave part and a second outer horizontal surface extended from an outer side of the convex part; and a first ventilation part disposed between the convex part and the concave part such that a space between the first lens and the second lens is connected with an outside environment. 
     The first ventilation part may include a gap formed between the convex part and the concave part. 
     The concave part may include an inclined first conical surface and a first inner horizontal surface extended to an inner side of the first conical surface, and the convex part may include a second conical surface facing the first conical surface and a second inner horizontal surface extended to an inner side of the second conical surface. 
     The first inner horizontal surface and the second inner horizontal surface may be spaced apart from each other. 
     A first portion of the second conical surface may be spaced apart from the first conical surface, and a second portion of the second conical surface may be closely adhered to the first conical surface. 
     The second portion of the second conical surface may include a vertical plane, and the first portion of the second conical surface may include an inclined curved surface. 
     Some portions of the first outer horizontal surface and the second outer horizontal surface may be closely adhered to each other, and other portions of the first outer horizontal surface and the second outer horizontal surface may be spaced apart from each other. 
     At least one of the first outer horizontal surface or the second outer horizontal surface may include a second ventilation part communicating with the first ventilation part. 
     The second ventilation part may be formed by a portion of the first outer horizontal surface having a surface roughness that is greater than a surface roughness of another portion of the first outer horizontal surface, or a portion of the second outer horizontal surface having a surface roughness that is greater than a surface roughness of another portion of the second outer horizontal surface. 
     The second ventilation part may include a groove formed in at least one of the first outer horizontal surface or the second outer horizontal surface. 
     The lens module may further include a lens barrel in which the first lens and the second lens are attached to be laminated. 
     The lens module may further include a third ventilation part in communication with the second ventilation part between a side surface of the second lens and an inner surface of the lens barrel, wherein the side surface of the second lens and the inner surface of the lens barrel are connected to each other. 
     The third ventilation part may be formed by a portion of the side surface of the second lens having a surface roughness that is greater than a surface roughness of another portion of the side surface of the second lens, or a portion of the inner surface of the lens barrel having a surface roughness that is greater than a surface roughness of the another portion of the inner surface of the lens barrel. 
     The third ventilation part may include a groove formed in at least one of the side surface of the second lens or the inner surface of the lens barrel. 
     According to another general aspect, a lens module includes: a lens barrel; a first lens and a second lens attached to be laminated in the lens barrel; and air channels formed between the first lens and the second lens and between the second lens and the lens barrel such that a space between the first lens and the second lens is connected with an outside environment. 
     The first lens may include a concave part and the second lens may include a convex part coupled to the concave part. A portion of the convex part may not be in contact with the concave part, and another portion of the convex part may be in contact with the concave part. A portion of a side surface of the second lens may not be in contact with an inner surface of the lens barrel, and another portion of the side surface of the second lens may be in contact with the inner surface of the lens barrel. 
     The air channels may be formed by roughened surfaces of the first lens or roughened surfaces of the second lens. 
     The air channels may be formed by grooves in the first lens or grooves in the second lens. 
     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 cross-sectional view of a lens module according to an example. 
         FIG. 2  is an enlarged view of part A of  FIG. 1 . 
         FIG. 3  is a perspective view of a second lens provided in the lens module according to an example. 
         FIG. 4  is a view illustrating a modified example of a second ventilation part and a third ventilation part of the lens module. 
         FIG. 5  is a perspective view of a second lens according to the modified example of  FIG. 4 . 
         FIGS. 6 and 7  are views illustrating second lenses including a modified example of a second conical surface of a convex part of the lenses. 
     
    
    
     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 size, proportions, and depiction 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 to one of ordinary skill in the art. 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 to one of ordinary skill in the art, with the exception of operations necessarily occurring in a certain order. Also, descriptions of functions and constructions that are well known to one of ordinary skill 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 so that this disclosure will be thorough and complete, and will convey the full scope of the disclosure to one of ordinary skill in the art. 
       FIG. 1  is a cross-sectional view of a lens module  100  according to an example.  FIG. 2  is an enlarged view of part A of  FIG. 1 .  FIG. 3  is a perspective view of a second lens  30  provided in the lens module  100  according to an example. 
     Referring to  FIGS. 1 through 3 , the lens module  100  includes a lens barrel  10  and lenses  20 ,  30 , and  40  attached to be laminated in the lens barrel  10 . 
     The lens barrel  10  may have a hollow cylindrical shape so that the lenses  20 ,  30 , and  40  photographing a subject are accommodated therein, and the lenses  20 ,  30 , and  40  are attached in the lens barrel  10  along an optical axis X. 
     A required number of the lenses  20 ,  30 , and  40  may be laminated depending on a design of the lens module  100 , and may have optical characteristics such as the same refractive index, different refractive indices, or the like. 
     The lenses  20 ,  30 , and  40  each include an optical part ( 20   a,    30   a,  and  40   a,  respectively) configured to refract incident light reflected from the subject, and a rib ( 20   b,    30   b,  and  40   b , respectively) extended from the optical part to an outer side of the respective lens. 
     Spacers  50  are disposed between the lenses  20 ,  30 , and  40  to maintain gaps between the lenses. The lenses  20 ,  30 , and  40  are disposed to be spaced apart from each other by a predetermined gap by the spacers  50 . The spacers  50  may be provided in a film shape, or may be provided in a shape having a predetermined thickness. 
     The spacers  50  may be coated with a light blocking material or may be attached with a light blocking film while preventing unnecessary incident light from being transmitted through the spacers  50 . In addition, the spacers  50  may be formed of an opaque material. For example, the spacers  50  may be formed of a nonferrous metal such as copper, aluminum, or the like. In this case, there may be advantages in that the spacers  50  may easily be formed and manufacturing costs of the spacers  50  may be reduced. 
     Referring to  FIG. 1 , although the example therein illustrates the first lens  20  disposed to be closest to an object side, the second lens  30  laminated on the first lens  20 , and the third lens  40  laminated on the second lens  30 , the scope of the present disclosure is not limited to this number of lenses. For example, the lens module  100  may include more or less than 3 lenses, depending on resolution to be implemented. 
     Hereinafter, a description will be provided in relation to the first lens  20  and the second lens  30  for convenience of explanation. In the following description, a first surface of each lens  20  and  30  refers to a surface thereof closest to an object side (or an object-side surface) and a second surface of each lens  20  and  30  refers to a surface thereof closest to an image side (or an image-side surface). 
     A second surface of the first lens  20  includes a concave part  24 . For example, the second surface of the first lens  20  includes an inclined first conical surface  21 , and a first inner horizontal surface  22  and a first outer horizontal surface  23  formed at opposite sides of the first conical surface  21 . The first outer horizontal surface  23  is formed in an outer direction (a direction moving away from an optical axis X) from the first conical surface  21 . Conversely, the first inner horizontal surface  22  is formed in an inner direction (a direction moving toward the optical axis X) from the first conical surface  21 . 
     Therefore, the second surface of the first lens  20  includes the concave part  24  formed to be concave by the inclined first conical surface  21  and the first inner horizontal surface  22  extended in the inner direction from the first conical surface  21 . Since the first conical surface  21  has an inclined curve, the concave part  24  has a conical shape. 
     A first surface of the second lens  30  facing the second surface of the first lens  20  includes a convex part  34  protruding to the concave part  24 . For example, the first surface of the second lens  30  includes an inclined second conical surface  31  formed at a position facing the first conical surface  21 , and a second inner horizontal surface  32  and a second outer horizontal surface  33  formed at opposite sides of the second conical surface  31 . The second outer horizontal surface  33  is formed in an outer direction (a direction moving away from the optical axis X) from the second conical surface  31 . Conversely, the second inner horizontal surface  32  may be formed in an inner direction (a direction moving toward the optical axis X) from the second conical surface  31 . 
     Therefore, the first surface of the second lens  30  includes the convex part  34  formed to protrude to the concave part  24  by the inclined second conical surface  31 , and the second inner horizontal surface  32  extended in the inner direction from the second conical surface  31 . Since the second conical surface  31  has an inclined curve, the convex part  34  has a conical shape. 
     The first inner horizontal surface  22  of the first lens  20  and the second inner horizontal surface  32  of the second lens  30  are spaced apart from each other, and the spacer  50  is disposed between the first inner horizontal surface  22  and the second inner horizontal surface  32 . In this case, the spacer  50  is closely adhered to the first inner horizontal surface  22  and is spaced apart from the second inner horizontal surface  32 . Therefore, a predetermined gap is formed between the second inner horizontal surface  32  and the spacer  50 . 
     The first lens  20  and the second lens  30  are attached to be laminated in the lens barrel  10 . For example, the convex part  34  is inserted in and coupled to the concave part  24 , and thus the first lens  20  and the second lens  30  are coupled to each other. As shown in  FIG. 1 , when the first lens  20  and the second lens  30  are coupled to each other, a space S is formed between an optical part of the first lens  20  and an optical part of the second lens  30 . 
     In a case in which the entire surfaces of the first lens  20  and the second lens  30  are coupled to each other such that they are closely adhered, it is difficult to externally discharge air from the space S. Therefore, when the first lens  20  and the second lens  30  are coupled to each other, the air in the space S expands, and thus a coupled position of the second lens  30  may be misaligned. In addition, since it is difficult to externally circulate the air in the space S after attachment of the lenses  20  and  30  has been completed, water vapor condensation may occur in the space S due to changes in temperature and humidity of a surrounding environment. Thus, the lens module according  100  includes a first ventilation part  60  between the convex part  34  and the concave part  24 , and thus the air in the space S is connected with the outside environment through the first ventilation part  60 . 
     The first ventilation part  60  may be a gap formed between the first conical surface  21  of the concave part  24  and the second conical surface  31  of the convex part  34 . The gap serves as an air channel allowing the air in the space S to be connected with the outside. 
     In the lens module  100 , a portion  31   a  of the second conical surface  31  is spaced apart from the first conical surface  21 , and another portion  31   b  ( FIGS. 1 and 3 ) of the second conical surface  31  is closely adhered to the first conical surface  21 . Thus, the air channel is formed in the portion  31   a  at which the first conical surface  21  and the second conical surface  31  are spaced apart from each other, and the air channel is used as the first ventilation part  60 . 
     Referring to  FIG. 2 , the portion  31   a  of the second conical surface  31  may have a cut shape. Therefore, as illustrated in  FIGS. 1 and 3 , the portion  31   a  of the second conical surface  31  may be a plane parallel to the optical axis, and the other portion  31   b  of the second conical surface  31  may be an inclined curved surface. Thus, as illustrated in  FIG. 3 , when being viewed from an optical axis direction, the convex part  34  may be formed to have a D′ shape. 
     Thus, in a case in which the convex part  34  is coupled to the concave part  24 , since the cut portion  31  a of the second conical surface  31  is spaced apart from the first conical surface  21 , the first ventilation part  60  may be formed between the convex part  34  and the concave part  24 . 
     Meanwhile, the first lens  20  includes the first outer horizontal surface  23  extended to an outer side of the concave part  24 , and the second lens  30  includes the second outer horizontal surface  33  closely adhered to the first outer horizontal surface  23 . Some portions of the first outer horizontal surface  23  and the second outer horizontal surface  33  may be closely adhered to each other, while other portions of the first outer horizontal surface  23  and the second outer horizontal surface  33  may be spaced apart from each other. Here, at least one of the first outer horizontal surface  23  or the second outer horizontal surface  33  includes a second ventilation part  70  which communicates with the first ventilation part  60 . 
     The second ventilation part  70  is formed by forming a surface roughness of a portion of at least one of the first outer horizontal surface  23  or the second outer horizontal surface  33  to be rougher than that of other portions of the first outer horizontal surface  23  or the second outer horizontal surface  33 . For example, the surface roughness may be changed by performing caustic etching on a surface of a portion of at least one of the first outer horizontal surface  23  or the second outer horizontal surface  33 . 
     Referring to  FIGS. 2 and 3 , the surface roughness of a portion  33   a  of the second outer horizontal surface  33  is formed to be rougher than that of the other portions of the second outer horizontal surface  33 . Thus, an air channel is formed between the first outer horizontal surface  23  and the second outer horizontal surface  33 , and the air channel serves as the second ventilation part  70 . 
     In the case in which the first lens  20  and the second lens  30  are attached to be laminated in the lens barrel  10 , side surfaces of the first lens  20  and the second lens  30  are in contact with an inner surface of the lens barrel  10 . 
     A third ventilation part  80  communicating with the second ventilation part  70  is provided between a side surface  35  of the second lens  30  and the inner surface of the lens barrel  10 . The third ventilation part  80  may be formed by changing surface roughness, similar to the second ventilation part  70 . For example, the third ventilation part  80  may be formed by forming a surface roughness of a portion of at least one of the side surface  35  of the second lens  30  or the inner surface of the lens barrel  10  to be rougher than that of the other portions of the second lens  30  or the lens barrel  10 . Referring to  FIGS. 2 and 3 , the roughness of a portion  35   a  of the side surface  35  is formed to be rougher than that of the other portions of the side surface  35 . 
     Thus, the first ventilation part  60 , the second ventilation part  70  and the third ventilation part  80 , which communicate with each other, are provided between the first lens  20  and the second lens  30 . As a result, the space S between the first lens  20  and the second lens  30  may be in communication with the outside environment. 
     That is, the space S between the first lens  20  and the second lens  30  is connected with the outside environment through the gap between the second inner horizontal surface  32  and the spacer  50 , the first ventilation part  60  formed between the first conical surface  21  and the second conical surface  31 , the second ventilation part  70  formed between the first outer horizontal surface  23  and the second outer horizontal surface  33 , and the third ventilation part  80  formed between the side surface  35  of the second lens  30  and the inner surface of the lens barrel  10 . 
     Thus, when the first lens  20  and the second lens  30  are coupled to each other, since expansion of the air between the first lens  20  and the second lens  30  may be prevented, misalignment of the attached position of the second lens  30  may be prevented. 
     In addition, even after the attachment of the first lens  20  and the second lens  30  is finished, since the space S between the first lens  20  and the second lens  30  is connected with the outside environment, the formation of water vapor condensation between the first lens  20  and the second lens  30  due to changes in temperature and humidity of the surrounding environment may be prevented. 
       FIG. 4  is a view illustrating a modified example of a second lens  30 ′ that, in conjunction with the first lens  20 , forms a second ventilation part  70 ′ and a third ventilation part  80 ′.  FIG. 5  is a perspective view of the second lens  30 ′ according to the modified example of  FIG. 4 . 
     Referring to  FIGS. 4 and 5 , a groove may be formed in at least one of the first outer horizontal surface  23  and the second outer horizontal surface  33 . More specifically, as shown in  FIG. 5 , a groove  36  is formed in the second outer horizontal surface  33  of the second lens  30 ′. An air channel is formed by the groove  36 , and the air channel serves as the second ventilation part  70 ′. 
     In addition, a groove may be formed in at least one of the side surface  35  of the second lens  30 ′ and the inner surface of the lens barrel  10 . More specifically, as shown in  FIG. 5 , a groove  37  is formed in the side surface  35  of the second lens  30 ′. Thus, an air channel is also formed between the side surface  35  of the second lens  30 ′ and the inner surface of the lens barrel  10 , and this air channel serves as the third ventilation part  80 ′. 
     Thus, the example of  FIGS. 4 and 5  lacks the roughened portions  33   a  and  35   a  of the second outer horizontal surface  33  and the side surface  35 , respectively, and instead includes the grooves  36  and  37  to form the second ventilation part  70 ′ and the third ventilation part  80 ′. 
       FIGS. 6 and 7  are views illustrating a modified example of a second conical surface of a convex part  34 ′ of second lenses  30 ″ and  30 ″&#39;, respectively. The lens  30 ″ shown in  FIG. 6  is similar to the lens  30  of  FIGS. 1-3 , with the exception of the convex part  34 ′, while the lens  30 ″ shown in  FIG. 7  is similar to the lens  30 ′ of  FIGS. 4 and 5 , with the exception of the of the convex part  34 ′. 
     Referring to  FIGS. 6 and 7 , a portion  31   a ′ of the second conical surface  31 ′ of the convex part  34 ′ of the second lenses  30 ″ and  30 ″′ may be cut such that one part of the cut portion  31   a ′ is a vertical plane, and another part of cut the portion  31   a ′ is an inclined curved surface. 
     More specifically, the cut portion  31   a ′ includes an inclined surface, having the same gradient as that of the inclined curved surface (portion  31   b,  as shown in  FIGS. 3 and 5 ) of the second conical surface  31 ′, provided between the second inner horizontal surface  32  and the vertical plane of the portion  31   a′.    
     When the convex part  34 ′ of the second lens  30 ″/ 30 ″′ is coupled to the concave part  24  of the first lens  20 , the inclined surface of the cut portion  31   a ′ may prevent an edge portion of the convex part  34 ′ of the second lens  30  from being damaged by contact shock. 
     As set forth above, according to the examples disclosed herein, the lens module allows the space between the lenses to be connected with the outside environment. As a result, an alteration of the attachment position of the lenses or the formation of water vapor condensation due to air between the lenses during an attachment process of the lenses or after the attachment of the lenses may be prevented. 
     While this disclosure includes specific examples, it will be apparent to one of ordinary skill in the art 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.