Patent Publication Number: US-2022221698-A1

Title: Optical system and projection device

Description:
CROSS-REFERENCE T 0  RELATED APPLICATIONS 
     The present application claims the benefit of Chinese Patent Application No. 202110045485.6 filed on Jan. 13, 2021. The disclosure of the aforementioned application is hereby incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     The present application relates to the technical field of optical imaging, in particular to an optical system and a projection device. 
     BACKGROUND 
     With the development of projection technology in recent years, projectors are widely used in household and commercial fields. Generally, ultra-short focus optical systems mostly adopt the structure of refraction and reflection, and multiple optical lenses are used together to correct the aberration of the optical system in the projection device, so as to achieve the effect of projecting super-large pictures with a short distance. Most ultra-short focus optical systems are used in laser TVs and engineering fields, and are well accepted by consumers. However, the traditional ultra-short focus optical systems are very bulky and inconvenient to move. 
     The foregoing content is only used to assist in understanding the technical solution of the present application, and does not mean that the foregoing content is recognized as prior art. 
     SUMMARY 
     The main objective of the present application is to provide an optical system and a projection device, aiming at solving the technical problems that the optical systems of related art are large in volume and inconvenient to move. 
     To achieve the above objective, the present application provides an optical system. The optical system includes a display unit, a first lens group, a second lens group, and a reflector which are sequentially arranged along a light transmission direction;
         the first lens group has a positive focal power;   the second lens group has a negative focal power;   a total of focal powers of the second lens group and the reflector is positive; and   a distance from a side of the first lens group close to the display unit to a side of the second lens group far away from the display unit is T 0 , and a distance from the side of the second lens group far away from the display unit to the reflector is T, T 0 /T is greater than or equal to 0.8 and less than or equal to 1.1.       

     Optionally, the focal power of the first lens group is greater than or equal to 0.1 and less than or equal to 0.2;
         an absolute value of the focal power of the second lens group is greater than or equal to 0.01 and less than or equal to 0.03; and   the total of the focal powers of the second lens group and the reflector is greater than or equal to 0.15 and less than or equal to 0.3.       

     Optionally, the first lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged along the light transmission direction;
         the second lens group includes an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens and a fourteenth lens arranged along the light transmission direction; and   the optical system further includes a diaphragm arranged between the first lens group and the second lens group.       

     Optionally, the first lens, the second lens, the third lens, the fifth lens, the seventh lens, the ninth lens, the tenth lens and the twelfth lens have positive focal powers; and the fourth lens, the sixth lens, the eighth lens, the eleventh lens, the thirteenth lens, and the fourteenth lens have negative focal powers. 
     Optionally, the second lens is a biconvex glass aspherical lens having a positive focal power ϕ2, and 0.05≤|ϕ|≤0.09; and
         the fourteenth lens includes a side close to the display unit and curved toward the display unit, and another side away from the display unit and curved toward the reflector, and the fourteenth lens has a positive focal power ϕ14, and 0.015≤|ϕ14|≤0.025.       

     Optionally, the fourteenth lens is a plastic aspherical lens having a negative focal power ϕ14′, and 0.01≤|14′|≤0.05; and
         the fourteenth lens has an outer diameter D 14 , and D 14 /T 0 ≥0.2.       

     Optionally, the third lens, the fourth lens and the fifth lens are cemented together to form a cemented lens;
         the sixth lens and the seventh lens are cemented together to form another cemented lens; and   the twelfth lens and the thirteenth lens are cemented together to form still another cemented lens.       

     Optionally, a distance between the first lens group and the second lens group is greater than or equal to 5.9 mm and less than or equal to 6.4 mm; and
         a distance between the second lens group and the reflector is greater than or equal to 29.25 mm and less than or equal to 29.75 mm.       

     Optionally, the display unit includes a DMD chip, the DMD chip is offset from an optical axis for more than 130%, and the DMD chip has a size greater than or equal to 0.23 inches and less than or equal to 0.33 inches. 
     In addition, the present application also provides a projection device including the optical system as described above. 
     The optical system includes a display unit, a first lens group, a second lens group and a reflector which are sequentially arranged along the light transmission direction. The first lens group has a positive focal power. The second lens group has a negative focal power. The total of the focal powers of the second lens group and the reflector is positive, the distance from the side of the first lens group close to the display unit to the side of the second lens group far away from the display unit is T 0 , the distance from the side of the second lens group far away from the display unit to the reflector is T, and T 0 /T is greater than or equal to 0.8 and less than or equal to 1.1. In this solution, an image light beam is emitted from the display unit, partial field curvature and distortion of the image light beam are corrected by the first lens group and the second lens group, and finally, the image light beam is reflected to a projection screen by the reflector to form an image, so that the distance between the display unit and the reflector is less than or equal to 80 mm and the projection ratio is 0.21 while maintaining high resolution, thus making the optical system ultra-small and portable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to more clearly explain the embodiments of the present application or the technical solutions in related art, the drawings required for the description of the embodiments or the related art will be briefly described below. It will be apparent that the drawings described below are only some embodiments of the present application, and other drawings may be obtained from the structure shown in those drawings without any creative effort by those of ordinary skill in the art. 
         FIG. 1  is a schematic structural diagram of an embodiment of an optical system and a projection device provided by the present application. 
         FIG. 2  is a schematic structural diagram of a first lens group in  FIG. 1 . 
         FIG. 3  is a schematic structural diagram of a second lens group in  FIG. 1 . 
         FIG. 4  is a schematic MTF curve diagram of the optical system and the projection device of  FIG. 1 . 
         FIG. 5  is a field curvature diagram and a distortion curve diagram of the optical system and the projection device of  FIG. 1 . 
     
    
    
     The realization of the objective, functional features and advantages of the present application will be further explained with reference to the accompanying drawings and in connection with the embodiments. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The technical solutions of the embodiments of the present application will be described in more detail below with reference to the accompanying drawings. It is obvious that the embodiments to be described are only some rather than all of the embodiments of the present application. All other embodiments obtained by persons skilled in the art based on the embodiments of the present application without creative efforts shall fall within the scope of the present application. 
     It should be noted that if there are directional indications in the embodiment of the present application, the directional indications are only used to explain the relative positional relationship, movement, etc. between the components in a specific posture. If the specific posture changes, the directional indication changes accordingly. 
     In addition, if there are descriptions relating to “first”, “second”, etc. in embodiments of the present application, the descriptions of “first”, “second”, etc. are for descriptive purposes only and cannot be understood as indicating or implying relative importance or impliedly indicating the number of the indicated technical features. Thus, a feature defined as “first”, or “second” may explicitly or implicitly include at least one of the features. In addition, the meaning of “and/or” in the whole text includes three parallel solutions, taking “A and/or B” as an example, “A and/or B” includes only solution A, only solution B, or both solution A and solution B. Further, the technical solutions of the various embodiments can be combined with each other, but must be made based on the realization of those ordinary skilled in the art. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that such a combination of technical solutions does not exist, nor does it fall within the protection scope of the present application. 
     At present, the ultra-short focus projection device on the market mostly adopts the structure of refraction and reflection. In order to correct the aberration of the optical system in the projection device, a plurality of optical lenses are usually required to cooperate with each other in the optical system. In the related art, a refractive lens group in the optical system is usually provided with a plurality of lens groups, and the number of lenses in each lens group is large, resulting in a large volume of the optical system and the optical system being inconvenient to move. 
     In view of this, the present application provides an optical system and a projection device, aiming at solving the technical problems that the optical systems of related art are large in volume and inconvenient to move. Referring to  FIGS. 1 to 5 , an embodiment of the optical system and the projection device provided by the present application is shown. 
     Referring to  FIGS. 1 to 3 , an optical system  100  includes a display unit  1 , a first lens group  2 , a second lens group  3 , and a reflector  4  in sequence along a transmission direction of light. The first lens group  2  has a positive focal power, and the second lens group  3  has a negative focal power. The total of focal powers of the second lens group  3  and the reflector  4  is positive, a distance from a side of the first lens group  2  close to the display unit  1  to a side of the second lens group  3  far away from the display unit  1  is T 0 , a distance from the side of the second lens group  3  far away from the display unit  1  to the reflector  4  is T, and T 0 /T is greater than or equal to 0.8 and less than or equal to 1.1. In this solution, an image light beam is emitted from the display unit  1 , partial field curvature and distortion of the image light beam are corrected by the first lens group  2  and the second lens group  3 , and finally, the image light beam is reflected to a projection screen by the reflector  4  to form an image, so that the distance between the display unit  1  and the reflector  4  is less than or equal to 80 mm and the projection ratio is 0.21 while maintaining high resolution, thereby making the optical system  100  ultra-small and portable. 
     Understandably, the focal power is equal to the difference between the convergence of the beam of the image side and the convergence of the beam of the object side, which represents the ability of an optical element to deflect light. The greater the absolute value of the focal power is, the stronger the ability to bend light will be, and the smaller the absolute value of the focal power is, the weaker the ability to bend light will be. When the focal power is positive, the light is deflected to be convergent. When the power is negative, the light is deflected to be divergent. The focal power can be used to characterize a refractive surface of a lens (i.e., a surface of the lens), a lens or a system formed by multiple lenses (i.e., a lens group). 
     Further, the focal power of the first lens group  2  is greater than or equal to 0.1 and less than or equal to 0.2. The absolute value of the focal power of the second lens group  3  is greater than or equal to 0.01 and less than or equal to 0.03. The total of focal powers of the second lens group  3  and the reflector  4  is greater than or equal to 0.15 and less than or equal to 0.3. The resolution of the optical system  100  is improved by the above-mentioned focal power matching. 
     Further, referring to  FIGS. 2 and 3 , the first lens group  2  includes a first lens  21 , a second lens  22 , a third lens  23 , a fourth lens  24 , a fifth lens  25 , a sixth lens  26 , and a seventh lens  27  arranged along the transmission direction of light. The second lens group  3  includes an eighth lens  31 , a ninth lens  32 , a tenth lens  33 , an eleventh lens  34 , a twelfth lens  35 , a thirteenth lens  36 , and a fourteenth lens  37  arranged along the transmission direction of light. A diaphragm  5  is also arranged between the first lens group  2  and the second lens group  3 . The combination of the first lens  21  to the fourteenth lens  37  causes light rays to be refracted a plurality of times during transmission, thereby achieving the effect of reducing aberration. The diaphragm  5  is mainly used to limit the number of the light rays or the size of the field of view of the optical system  100 , and in particular, the diaphragm  5  is used to limit the number of light rays entering the eighth lens  31  from the seventh lens  27 . 
     Specifically, the first lens  21 , the second lens  22 , the third lens  23 , the fifth lens  25 , the seventh lens  27 , the ninth lens  32 , the tenth lens  33 , and the twelfth lens  35  have positive focal powers. The fourth lens  24 , the sixth lens  26 , the eighth lens  31 , the eleventh lens  34 , the thirteenth lens  36 , and the fourteenth lens  37  have negative focal powers. The lenses of the first lens  21  to the fourteenth lens  37  with different focal powers cause the light emitted from the display unit  1  to be refracted differently a plurality of times when passing through the first lens  21  to the fourteenth lens  37 , thereby further enabling the light to be transmitted to the reflector  4  with a small aberration. 
     Further, referring to  FIG. 4 , the second lens  22  is a biconvex glass aspherical lens, and the focal power ϕ2 of the second lens  22  is positive, where 0.05≤|ϕ2|≤0.09. The fourteenth lens  37  is curved toward the display unit  1  on a side close to the display unit  1  and toward the reflector  4  on a side away from the display unit  1 , and has a positive focal power ϕ14, where 0.015≤|ϕ14|≤0.025. When the above conditions are met, the field curvatures and distortions under different projection distances can be corrected, the resolutions under different projection distances can be kept unchanged, and the projection picture of larger than or equal to 40 inches and less than or equal to 100 inches can be realized. 
     Further, referring to  FIG. 5 , the fourteenth lens  37  is a plastic aspherical lens, and the focal power ϕ14′ of the fourteenth lens  37  is negative, where 0.01≤|ϕ14′|≤0.05. The fourteenth lens  37  has an outer diameter D 14 , where D 14 /T 0 ≥0.2. Therefore, when the output brightness is less than 1000 lumens, the optical focus does not drift, and the effect that the picture is still clear and no focusing is needed when the optical system  100  is turned on for a long time is achieved. 
     Further, the third lens  23 , the fourth lens  24  and the fifth lens  25  are cemented together to form a cemented lens, the sixth lens  26  and the seventh lens  27  are cemented together to form another cemented lens, and the twelfth lens  35  and the thirteenth lens  36  are cemented together to form still another cemented lens to eliminate chromatic aberration. It is understandable that the chromatic aberration is formed after the light passing through a lens, which makes the imaging blurred. Therefore, chromatic aberration has become a serious defect in lens imaging. A cemented lens is formed by cementing a plurality of lenses with different materials. When light passes through one of the lenses of the cemented lens and is refracted, chromatic aberration is generated, and when the refracted light continues to pass through another lens, the generated chromatic aberration is just reversed and can counteract the previous chromatic aberration, thereby achieving the purpose of eliminating chromatic aberration. 
     Further, the projection range of the optical system  100  can be ranged from 40 inches to 100 inches, and the second lens group  3  moves to focus so as to adjust the resolution of the picture at different projection distances. The distance between the first lens group  2  and the second lens group  3  during focusing is greater than or equal to 5.9 mm and less than or equal to 6.4 mm. The distance between the second lens group  3  and the reflector  4  is greater than or equal to 29.25 mm and less than or equal to 29.75 mm, thereby realizing high-resolution imaging. 
     Further, the display unit  1  includes a digital micromirror device (DMD) chip  11  which is offset from the optical axis for more than 130%. The size of the DMD chip  11  is greater than or equal to 0.23 inches, and less than or equal to 0.33 inches, so that the image definition is improved while the volume is reduced. Specifically, the display unit  1  further includes an equivalent prism  12  disposed between the DMD chip  11  and the first lens group  2 , which can reduce the aberration caused by refractive transmission of light rays. 
     In the present embodiment, each of the equivalent prism  12  and the lenses of the first lens  21  to the fourteenth lens  37  has a light entry surface and a light exit surface along the light transmission direction. Specifically, in the figures, the light entry surface and the light exit surface of the equivalent prism  12  are indicated by S 1  and S 2  respectively, the light entry surface and the light exit surface of the first lens  21  are indicated by reference numbers S 3  and S 4  respectively, the light entry surface and the light exit surface of the second lens  22  are indicated by reference numbers S 5  and S 6  respectively, the light entry surface of the third lens  23  is indicated by reference number S 7 , the light exit surface of the fifth lens  25  is indicated by reference number S 10 , the light entry surface of the sixth lens  26  is indicated by reference number S 11 , the light exit surface of the seventh lens  27  is indicated by reference number S 13 , the light entry surface and the light exit surface of the eighth lens  31  are indicated by reference numbers S 14  and S 15  respectively, the light entry surface and the light exit surface of the ninth lens  32  are indicated by reference numbers S 16  and S 17  respectively, the light entry surface and the light exit surface of the tenth lens  33  are indicated by reference numbers S 18  and S 19  respectively, the light entry surface and the light exit surface of the eleventh lens  34  are indicated by reference numbers S 21  and S 20  respectively, the light exit surface of the twelfth lens  35  is indicated by reference number S 22 , the light exit surface of the thirteenth lens  36  is indicated by reference number S 25 , and the light entry surface and the light exit surface of the fourteenth lens  37  are indicated by reference numbers S 26  and S 27  respectively. Further, a cementing surface of the third lens  23  and the fourth lens  24  is indicated by reference number S 8 , a cementing surface of the fourth lens  24  and the fifth lens  25  is indicated by reference number S 9 , a cementing surface of the sixth lens  26  and the seventh lens  27  is indicated by reference number S 12 , and a cementing surface of the twelfth lens  35  and the thirteenth lens  36  is indicated by reference number S 23 . 
     Specifically in this embodiment the parameters of the optical system  100  are shown in the following table. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Parameters Of Each Lens Of The Optical System 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 reference 
                   
                 Radius 
                 Thickness/ 
                 Optical 
               
               
                 Surface 
                 number 
                 Type 
                 R/mm 
                 mm 
                 material 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 IMA 
                   
                 Image plane 
                 Infinity 
                 0 
                   
               
               
                 The light entry surface 
                 S1 
                 Standard 
                 Infinity 
                 −8 
                 H-LAF50B 
               
               
                 of the equivalent prism 
                   
                   
                   
                   
                   
               
               
                 The light exit surface  
                 S2 
                 Standard 
                 Infinity 
                 −3.75 
                   
               
               
                 of the equivalent prism 
                   
                   
                   
                   
                   
               
               
                 The light entry surface 
                 S3 
                 Standard 
                 11.07011 
                 −2.57 
                   
               
               
                 of the first lens 
                   
                   
                   
                   
                   
               
               
                 The light exit surface  
                 S4 
                 Standard 
                 −453.171 
                 −2.44 
                 FC5 
               
               
                 of the first lens 
                   
                   
                   
                   
                   
               
               
                 The light entry surface  
                 S5 
                 Aspheric 
                 7.483362 
                 −0.1 
                   
               
               
                 of the second lens 
                   
                   
                   
                   
                   
               
               
                 The light exit surface 
                 S6 
                 Aspheric 
                 −106.812 
                 −2.87 
                 M-FCD1 
               
               
                 of the second lens 
                   
                   
                   
                   
                   
               
               
                 The light entry surface 
                 S7 
                 Standard  
                 5.717516 
                 −0.1 
                   
               
               
                 of the third lens 
                   
                   
                   
                   
                   
               
               
                 M1 
                 S8 
                 Standard  
                 Infinity 
                 −2.27 
                 FCD1 
               
               
                 M2 
                 S9 
                 Standard  
                 3.394409 
                 −0.54 
                 H-ZF52A 
               
               
                 The light exit surface 
                 S10 
                 Standard  
                 Infinity 
                 −1.90 
                 FCD1 
               
               
                 of the fifth lens 
                   
                   
                   
                   
                   
               
               
                 The light entry surface 
                 S11 
                 Standard  
                 −12.821 
                 −0.16 
                   
               
               
                 of the sixth lens 
                   
                   
                   
                   
                   
               
               
                 M3 
                 S12 
                 Standard  
                 3.567711 
                 −1.25 
                 H-ZLAF50B 
               
               
                 The light exit surface  
                 S13 
                 Standard  
                 −13.491 
                 −1.25 
                 H-ZF52 
               
               
                 of the seventh lens 
                   
                   
                   
                   
                   
               
               
                 STO 
                   
                 Diaphragm 
                 Infinity 
                 −0.35 
                   
               
               
                 The light entry surface  
                 S14 
                 Standard  
                 −23.746 
                 −5.8 
                   
               
               
                 of the eighth lens 
                   
                   
                   
                   
                   
               
               
                 The light exit surface  
                 S15 
                 Standard  
                 23.74601 
                 −0.54 
                 FCD1 
               
               
                 of the eighth lens 
                   
                   
                   
                   
                   
               
               
                 The light entry surface 
                 S16 
                 Standard  
                 75.04273 
                 −2.81 
                   
               
               
                 of the ninth lens 
                   
                   
                   
                   
                   
               
               
                 The light exit surface  
                 S17 
                 Standard  
                 −14.282 
                 −1.79 
                 H-ZF10 
               
               
                 of the ninth lens 
                   
                   
                   
                   
                   
               
               
                 The light entry surface 
                 S18 
                 Standard  
                 14.00674 
                 −1.83 
                   
               
               
                 of the tenth lens  
                   
                   
                   
                   
                   
               
               
                 The light exit surface 
                 S19 
                 Standard  
                 Infinity 
                 −2.13 
                 H-F1 
               
               
                 of the tenth lens  
                   
                   
                   
                   
                   
               
               
                 The light entry surface 
                 S20 
                 Standard  
                 −12.4141 
                 −1.36 
                   
               
               
                 of the eleventh lens  
                   
                   
                   
                   
                   
               
               
                 The light exit surface  
                 S21 
                 Standard  
                 −167.595 
                 −0.795 
                 H-ZF52A 
               
               
                 of the eleventh lens  
                   
                   
                   
                   
                   
               
               
                 The light entry surface 
                 S22 
                 Standard  
                 14.95415 
                 −0.1 
                   
               
               
                 of the twelfth lens  
                   
                   
                   
                   
                   
               
               
                 M4 
                 S23 
                 Standard  
                 −80.4815 
                 −2.90 
                 H-QK3L 
               
               
                 The light exit surface 
                 S24 
                 Standard  
                 50.16436 
                 −1.09 
                 TAFD25 
               
               
                 of the thirteenth lens  
                   
                   
                   
                   
                   
               
               
                 The light entry surface 
                 S25 
                 Aspheric 
                 −29.7553 
                 −1.77 
                   
               
               
                 of the fourteenth lens 
                   
                   
                   
                   
                   
               
               
                 The light exit surface  
                 S26 
                 Aspheric 
                 28.25564 
                 −1.81 
                 E48R 
               
               
                 of the fourteenth lens  
                   
                   
                   
                   
                   
               
               
                 Reflector 
                 S27 
                 Aspheric 
                 −13.472 
                 −29.50 
                 MIRROR 
               
               
                 OBJ 
                   
                 Object plane 
                 Infinity 
                 275 
                   
               
               
                   
               
            
           
         
       
     
     The shapes of the aspheric surfaces of the reflector  4 , the second lens  22 , and the fourteenth lens  37  satisfy the following equation: 
         Z=cy   2 /{1+√{square root over (1−(1+ k ) c   2   y   2 )}}+ a   1   y   2   +a   2   y   4   +a   3   y   6   +a   4   y   8   +a   5   y   10   +a   6   i   12   +a   7   y   14   ,+a   8   y   16 ,
 
     where c is a curvature corresponding to the radius; y is a radial coordinate (the unit of the radial coordinate is the same as the unit of the lens length); k is a conic coefficient, when k is less than −1, the curve of the surface shape of the lens is hyperbola, when k is equal to −1, the curve of the surface shape of the lens is parabola, when k is between −1 and 0, the curve of the surface shape of the lens is ellipse, when k is equal to 0, the curve of the surface shape of the lens is circular, and when k is greater than 0, the curve of the surface shape of the lens is oblate; a1 to a8 represent coefficients corresponding to radial coordinates. 
     In this embodiment, the even order coefficients of each aspheric surface are shown in the following table. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Coefficients Of Reflector And The Aspheric Lenses Including 
               
               
                 The Second Lens and The Fourteenth Lens 
               
            
           
           
               
               
               
               
               
               
            
               
                 reference 
                   
                   
                   
                   
                   
               
               
                 number 
                 S6 
                 S7 
                 S25 
                 S26 
                 S27 
               
               
                   
               
               
                 K 
                 −0.004199897 
                 −109.2158 
                 −1.674944 
                  2.713719 
                 −2.477442 
               
               
                 A1 
                  0 
                   0 
                  0 
                  0 
                  0 
               
               
                 A2 
                 −2.0487294 
                   0.00044232136 
                  6.0197028 
                 −0.00050027906 
                 −5.7342322 
               
               
                   
                 E−005 
                   
                 E−005 
                   
                 E−005 
               
               
                 A3 
                 −7.6341053 
                  −1.8082764 
                 −1.8936162 
                  4.5976099  
                  1.6145479 
               
               
                   
                 E−006 
                 E−005 
                 E−006 
                 E−006 
                 E−007 
               
               
                 A4 
                  9.6321341 
                   2.9705106 
                  1.337263 
                 −5.3309026  
                 −4.2100693 
               
               
                   
                 E−007 
                 E−006 
                 E−007 
                 E−008 
                 E−010 
               
               
                 A5 
                 −5.8305605 
                  −2.8559975 
                 −5.435665 
                  3.0688044 
                 −8.7602982 
               
               
                   
                 E−008 
                 E−007 
                 E−009 
                 E−010 
                 E−013 
               
               
                 A6 
                 −5.8305605 
                   1.4890765 
                 −2.0923673 
                 −2.0923673 
                  1.133532 
               
               
                   
                 E−008 
                 E−008 
                 E−015 
                 E−015 
                 E−014 
               
               
                 A7 
                  1.8345504 
                  −3.8937673 
                 −9.8291941 
                  1.6861226 
                 −3.5950126 
               
               
                   
                 E−009 
                 E−010 
                 E−013 
                 E−015 
                 E−010 
               
               
                 A8 
                  2.3048197 
                   4.9982209 
                  2.8249201 
                 −3.6334168 
                  4.9505331 
               
               
                   
                 E−013 
                 E−012 
                 E−015 
                 E−018 
                 E−020 
               
               
                   
               
            
           
         
       
     
     E-001 represents 10 −1 , E-002 represents 10 −2  . . . , E-010 represents 10 −10 , and so on, and E-N represents 10 −N . 
     The above is only an alternative embodiment of the present application, and is not to limit the scope of the present application. Any equivalent structural transformation made by using the contents of the present specification and drawings, or any direct/indirect application in other related technical fields, under the inventive concept of the present application, is included in the scope of the present application.