Patent Publication Number: US-2023155054-A1

Title: Optical module

Description:
TECHNICAL FIELD 
     The present technology relates to an optical module and particularly to an optical module including a light emitting element and a light receiving element. 
     BACKGROUND ART 
     In the related art, an optoelectronic module in which a radiation member (light emitting element) and a detection member (light receiving element) that detects reflected light of light emitted from the radiation member are housed in one housing has been proposed (see Patent Document 1). 
     CITATION LIST 
     Patent Document 
     
         
         Patent Document 1: PCT International Application Publication No. 2015-509184 
       
    
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     However, the light emitting side and the light receiving side are formed in the same housing in the optoelectronic module described in Patent Document 1, it is difficult to independently adjust the positions of the light emitting side and the light receiving side, and there is thus a limit in improving performance. 
     The present technology was made in view of such a circumstance and is for improving performance of an optical module including a light emitting element and a light receiving element. 
     Solutions to Problems 
     An optical module according to an aspect of the present technology includes: a substrate; a light emitting element that is disposed on the substrate; a light receiving element that is disposed on the substrate at a predetermined interval from the light emitting element; a first casing that is disposed on the substrate and surrounds a periphery of the light emitting element; a second casing that is disposed on the substrate and surrounds a periphery of the light receiving element; a light emitting lens that is housed in the first casing and is disposed on an optical axis of the light emitting element; and a light receiving lens that is housed in the second casing and is disposed on an optical axis of the light receiving element, in which a first diameter of one lens out of the light emitting lens and the light receiving lens in a first direction toward an optical axis of the other lens with reference to an optical axis of the one lens is shorter than a second diameter of the one lens in a second direction that is orthogonal to the first direction. 
     According to an aspect of the present technology, emitted light emitted from the light emitting element is emitted via the light emitting lens, and reflected light of the emitted light is incident on the light receiving element via the light receiving lens. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a sectional view schematically illustrating a first embodiment of an optical module to which the present technology is applied. 
         FIG.  2    is a plan view schematically illustrating the first embodiment of the optical module to which the present technology is applied. 
         FIG.  3    is a diagram illustrating an example of an optical path of the optical module. 
         FIG.  4    is a plan view schematically illustrating a first modification example of the first embodiment of the optical module. 
         FIG.  5    is a plan view schematically illustrating a second modification example of the first embodiment of the optical module. 
         FIG.  6    is a plan view schematically illustrating a third modification example of the first embodiment of the optical module. 
         FIG.  7    is a sectional view schematically illustrating a second embodiment of an optical module to which the present technology is applied. 
         FIG.  8    is a sectional view schematically illustrating a third embodiment of an optical module to which the present technology is applied. 
         FIG.  9    is a perspective view schematically illustrating a fourth embodiment of an optical module to which the present technology is applied. 
         FIG.  10    is a sectional view schematically illustrating a fourth embodiment of an optical module to which the present technology is applied. 
         FIG.  11    is a block diagram illustrating an example of a schematic configuration of an in-vivo information acquisition system. 
         FIG.  12    is a block diagram illustrating an example of a schematic configuration of a vehicle control system. 
         FIG.  13    is an explanatory diagram illustrating an example of installation positions of an outside-vehicle information detecting section and an imaging section. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, modes for carrying out of the present technology will be described. The description will be given in the following order.
         1. First Embodiment   2. Modification examples of first embodiment   3. Second Embodiment   4. Third Embodiment   5. Fourth Embodiment   6. Modification examples   7. Application examples   8. Others       

     1. First Embodiment 
     First, a first embodiment of the present technology will be described with reference to  FIGS.  1  to  3   . 
     &lt;Configuration Example of Optical Module  1   a&gt;   
       FIG.  1    is a sectional view schematically illustrating an optical module  1   a  to which the present technology is applied.  FIG.  2    is a plan view schematically illustrating the optical module  1   a  to which the present technology is applied. 
     The optical module  1   a  is a module that emits emitted light and receives reflected light obtained by the emitted light being reflected by an object. The optical module  1   a  is used, for example, in a distance measuring sensor that measures a distance to an object. Hereinafter, a case where the optical module  1   a  is used for a distance measuring sensor will be described. 
     The optical module  1   a  includes a substrate  11 , a light emitting element  12 , a light receiving element  13 , a light emitting module  14   a , and a light receiving module  15   a.    
     The light emitting element  12  and the light receiving element  13  are aligned and disposed at a predetermined interval on the substrate  11 . The light emitting element  12  includes, for example, an element that emits light, such as a semiconductor laser (LD). The light receiving element  13  includes, for example, an element that converts incident light into an electric signal, such as an image sensor or a photodiode. 
     The light emitting module  14   a  is a module including a light emitting optical system that causes emitted light emitted from the light emitting element  12  to be emitted toward an object that is a target of distance measurement (hereinafter, referred to as a target). The light emitting module  14   a  includes a holder  31   a  and a light emitting lens group LTa. 
     The holder  31   a  is a cylindrical casing including resin or metal having a light shielding property and stores the light emitting lens group LTa. The holder  31   a  is disposed on the substrate  11  to surround the periphery of the light emitting element  12  and is bonded and fixed to the substrate  11  with a light shielding member  16  (for example, a resin having a light shielding property). As a result, a space between the lower end of the holder  31   a  and the substrate  11  is light-shielded, and the emitted light emitted from the light emitting element  12  is prevented from leaking to the outside of the light emitting module  14   a  from a portion other than the outermost (closest to the object side) lens LT 1   a  in the light emitting lens group LTa. In particular, the light receiving element  13  is prevented from directly receiving the emitted light emitted from the light emitting element  12 . 
     In addition, the position of the holder  31   a  is adjusted such that the optical axis of each lens in the light emitting lens group LTa coincides with the optical axis of the light emitting element  12 . 
     Then, the emitted light emitted from the light emitting element  12  is emitted from the light emitting module  14   a  toward the target via the light emitting lens group LTa as illustrated by the dotted line in  FIG.  3   . 
     The light receiving module  15   a  is a module that includes a light receiving optical system that receives reflected light obtained by the emitted light being reflected by the target and causes the reflected light to be incident on the light receiving element  13 . The light receiving module  15   a  includes a holder  41   a , a light receiving lens group LRa, and a bandpass filter (BPF)  42   a.    
     The holder  41   a  is a cylindrical casing including a resin or metal having a light shielding property and houses the light receiving lens groups LRa and BPF  42   a . The holder  41   a  is disposed on the substrate  11  to surround the periphery of the light receiving element  13  and is bonded and fixed to the substrate  11  with the light shielding member  16  similarly to the holder  31   a . As a result, a space between the lower end of the holder  41   a  and the substrate  11   a  is light-shielded, and external light is prevented from being incident on the light receiving element  13  from a part other than the outermost (closest to the object side) lens LR 1   a  in the light receiving lens group LRa. 
     Also, the position of the holder  41   a  is adjusted such that the optical axis of each lens in the light receiving lens group LRa coincides with the optical axis of the light receiving element  13 . 
     Then, the reflected light obtained by the emitted light being reflected by the target is transmitted through the light receiving lens group LRa, a predetermined wavelength component is extracted by the BPF  42   a , and the light is then incident on the light receiving surface of the light receiving element  13  as illustrated by the dotted line in  FIG.  3   . 
     Here, the holder  31   a  of the light emitting module  14   a  is independent from the holder  41   a  of the light receiving module  15   a . Therefore, it is possible to independently perform adjustment of the position of the light emitting module  14   a  relative to the light emitting element  12  and adjustment of the position of the light receiving module  15   a  relative to the light receiving element  13 . 
     As a result, it is possible to improve the positioning accuracy of the light emitting optical system relative to the light emitting element  12  and the positioning of the light receiving optical system relative to the light receiving element  13 . In addition, it is possible to independently perform fine adjustment of the positions of the light emitting optical system and the light receiving optical system in accordance with variations and the like of performance of each of the optical elements including the light emitting element  12  and the light receiving element  13 . 
     As a result, it is possible to improve optical performance of the optical module  1   a . For example, it is possible to irradiate the target with more emitted light and to receive more reflected light, the amount of information that the optical module  1   a  can acquire increases, and distance measurement accuracy is improved. 
     Also, an optical axis φT 1   a  of the lens LT 1   a  in the light emitting lens group LTa is biased in the direction of an optical axis (an optical axis φR 1   a  of the lens LR 1   a , for example) of the light receiving module  15   a  from the center of the lens LT 1   a  as illustrated in  FIG.  2   . More specifically, the lens LT 1   a  has a D-cut shape having a linear shape on a side on which the lens LT 1   a  is adjacent to the light receiving module  15   a  (lens LR 1   a ). Therefore, the diameter d 1  of the lens LT 1   a  in a first direction toward the optical axis φR 1   a  of the lens LR 1   a  with reference to the optical axis φT 1   a  of the lens LT 1   a  is shorter than the diameter d 2  of the lens LT 1   a  in a second direction that is orthogonal to the first direction. 
     Note that the diameter d 1  is the shortest diameter (hereinafter, referred to as the shortest lens diameter) among the diameters of the lens LT 1   a  with reference to the optical axis φT 1   a  and is set to be equal to or greater than an effective diameter of the lens LT 1   a . The effective diameter of the lens LT 1   a  is the maximum value among the diameters with reference to the optical axis φT 1   a  of a region in which the emitted light emitted from the light emitting element  12  is assumed to pass through the lens LT 1   a . In other words, substantially all the emitted light emitted from the light emitting element  12  passes through the region within a range of the effective diameter around the optical axis φT 1   a  of the lens LT 1   a  at the center. 
     As described above, even if the lens LT 1   a  is formed into the D-cut shape, optical performance of the light emitting module  14   a  can be assured by setting the shortest lens diameter to be equal to or greater than the effective diameter. 
     Also, although detailed illustration is omitted, the other lenses in the light emitting lens group LTa also have D-cut shapes having straight shapes on the side of the light receiving module  15   a  similarly to the lens LT 1   a . Moreover, the shortest lens diameter of each of the other lenses in the light emitting lens group LTa is also set to be equal or greater than the effective diameter. 
     Note that, since a region through which emitted light passes differs for each lens in the light emitting lens group LTa, the effective diameter of each lens is different. 
     In this manner, it is possible to shorten the distance (hereinafter, referred to as a base line length) between the optical axes of the light emitting module  14   a  and the light receiving module  15   a  even if a structure in which the holder  31   a  of the light emitting module  14   a  and the holder  41   a  of the light receiving module  15   a  are independent from each other is employed. Note that the baseline length is the distance between the optical axis φT 1   a  of the lens LT 1   a  and the optical axis φR 1   a  of the lens LR 1   a  in  FIG.  2   , for example. 
     As a result, it is possible to shorten the interval between the light emitting element  12  and the light receiving element  13  and to reduce the size of the optical module  1   a . Also, it is possible to cause the incidence angle of the reflected light on the light receiving module  15   a  to be close to 0 degrees, for example, by the interval between the light emitting element  12  and the light receiving element  13  being shortened, and as a result, a distance measurement rule is improved. 
     In addition, leakage of the emitted light emitted from the light emitting element  12  from the part other than the lens LT 1   a  to the outside of the light emitting module  14   a  is curbed by light-shielding the periphery of the light emitting element  12  with the holder  31   a  and the light shielding member  16 . Moreover, incidence of external light on the light receiving element  13  from the part other than the lens LR 1   a  is curbed by light-shielding the periphery of the light receiving element  13  with the holder  41   a  and the light shielding member  16 . 
     As a result, the light receiving element  13  can receive more reflected light of the emitted light emitted from the light emitting element  12 . In addition, receiving light other than the reflected light by the light receiving element  13  is curbed. As a result, it is possible to improve performance of the optical module  1   a.    
     2. Modification Examples of First Embodiment 
     Next, modification examples of the first embodiment will be described with reference to  FIGS.  4  to  6   . In each modification example, the shape of an optical element of at least one optical system out of the light emitting optical system and the light receiving optical system is different from that in the first embodiment. 
     First Modification Example 
     First, a first modification example will be described with reference to  FIG.  4   . The first modification example is different from the first embodiment in that the optical element of the light receiving optical system has a D-cut shape. 
       FIG.  4    is a plan view schematically illustrating an optical module  1   b . Note that the same reference signs are applied to the parts corresponding to those of the optical module  1   a  in  FIG.  2    in the drawing, and description thereof will be appropriately omitted. Also, illustration of the substrate  11  is omitted in  FIG.  4   . 
     The optical module  1   b  is different from the optical module  1   a  in that the optical module  1   b  includes a light receiving module  15   b  instead of the light receiving module  15   a.    
     The light receiving module  15   b  is different from the light receiving module  15   a  in that the light receiving module  15   b  includes a holder  41   b , a light receiving lens group LRb, and a BPF  42   b  instead of the holder  41   a , the light receiving lens group LRa, and the BPF  42   a . Note that illustration of the BPF  42   b  is omitted. 
     In this example, each lens in the light receiving lens group LRb has a D-cut shape having a linear shape on a side on which the lens is adjacent to the light emitting module  14   a  (light emitting lens group LTa) similarly to each lens in the light emitting lens group LTa. 
     Moreover, the shortest lens diameter of each lens in the light receiving lens group LRb is set to be equal to or greater than its effective diameter. 
     Furthermore, the holder  41   b  has a shape that is different from that of the holder  41   a  in accordance with a difference in shapes of optical elements to be housed. 
     In this manner, it is possible to further shorten the baseline length and to further reduce the size of the optical module  1   b  by forming the optical element of the light receiving optical system into a D-cut shape as well. In addition, it is possible to cause the incidence angle of the reflected light on the light receiving module  15   b  to be closer to 0 degrees, and as a result, distance measurement accuracy is improved. 
     Second Modification Example 
     Next, a second modification example will be described with reference to  FIG.  5   . The second modification example is different from the first embodiment in that the optical element of the light emitting optical system has an I-cut shape. 
       FIG.  5    is a plan view schematically illustrating an optical module  1   c . Note that the same reference signs are applied to the parts corresponding to those of the optical module  1   a  in  FIG.  2    in the drawing, and description thereof will be appropriately omitted. Also, illustration of the substrate  11  is omitted in  FIG.  5   . 
     The optical module  1   c  is different from the optical module  1   a  in that the optical module  1   c  includes a light emitting module  14   b  instead of the light emitting module  14   a.    
     The light emitting module  14   b  is different from the light emitting module  14   a  in that the light emitting module  14   b  includes a holder  31   b  and a light emitting lens group LTb instead of the holder  31   a  and the light emitting lens group LTa. 
     In this example, each lens in the light emitting lens group LTb has an I-cut shape. In other words, each lens in the light emitting lens group LTb has a linear shape not only on the side on which the lens is adjacent to the light receiving module  15   a  (light receiving lens group LRa) but also on the side opposite thereto. 
     Moreover, the shortest lens diameter of each lens in the light emitting lens group LTb is set to be equal to or greater than its effective diameter. 
     Furthermore, the holder  31   b  has a shape that is different from that of the holder  31   a  in accordance with a difference in shapes of optical elements to be housed. 
     In this manner, it is possible to further reduce the size of the light emitting module  14   b  and to further reduce the size of the optical module  1   c  by forming the optical element of the light emitting optical system into an I-cut shape. 
     Third Modification Example 
     Next, a third modification example will be described with reference to  FIG.  6   . The third modification example is different from the first embodiment in the shapes of the optical elements of the light receiving optical system and the light emitting optical system. 
       FIG.  6    is a plan view schematically illustrating an optical module  1   d . Note that the same reference signs are applied to the parts corresponding to those of the optical module  1   a  in  FIG.  2    in the drawing, and description thereof will be appropriately omitted. Also, illustration of the substrate  11  is omitted in  FIG.  6   . 
     The optical module  1   d  is different from the optical module  1   a  in that the optical module  1   d  includes a light emitting module  14   c  and a light receiving module  15   c  instead of the light emitting module  14   a  and the light receiving module  15   a.    
     The light emitting module  14   c  is different from the light emitting module  14   a  in that the light emitting module  14   c  includes a holder  31   c  and a light emitting lens group LTc instead of the holder  31   a  and the light emitting lens group LTa. 
     The light receiving module  15   c  is different from the light receiving module  15   a  in that the light receiving module  15   c  includes a holder  41   c , a light receiving lens group LRc, and a BPF  42   c  instead of the holder  41   a , the light receiving lens group LRa, and the BPF  42   a . Note that illustration of the BPF  42   c  is omitted. 
     In this example, the outer periphery of each of the lenses in the light emitting lens group LTc and the light receiving lens group LRc has a rectangular shape. 
     Also, a lens section LT 1 Ac that has a D-cut shape having a linear shape on the side of the light receiving module  15   c  similarly to the lens LT 1   a  in  FIG.  2    and substantially functions as a lens is formed at the outermost (closest to the object side) lens LT 1   c  in the light emitting lens group LTc. Furthermore, the diameter d 11  of the lens LT 1   a  in a first direction toward an optical axis φR 1   c  of the outermost (closest to the object side) lens LR 1   c  in the light receiving lens group LRc with reference to an optical axis φT 1   c  of the lens LT 1   a  is shorter than the diameter d 12  of the lens LT 1   c  in a second direction that is orthogonal to the first direction. Also, the diameter d 11  is set to be equal to or greater than the effective diameter of the lens LT 1   a.    
     Furthermore, although illustration is omitted, the outer peripheries of the other lenses in the light emitting lens group LTc have rectangular shapes similarly to the lens LT 1   c , and also, lens portions with D-cut shapes having linear shapes on the side of the light receiving module  15   c  are formed. Furthermore, each of the shortest lens diameters of the other lenses in the light emitting lens group LTc is also set to be equal or greater than the effective diameter. 
     A circular lens section LR 1 Ac that substantially functions as a lens is formed at the lens LR 1   c . The optical axis φR 1   c  of the lens LR 1   c  coincides with the center of the lens LR 1   c.    
     Also, the outer peripheries of the other lenses in the light receiving lens group LRc also have rectangular shapes similarly to the lens LR 1   c  and the optical axis coincides with the center, although illustration is omitted. 
     Furthermore, the holder  31   c  has a shape that is different from that of the holder  31   a  in accordance with a difference in shapes of optical elements to be housed. The holder  41   c  has a shape that is different from the shape of the holder  41   a  due to a difference in shapes of optical elements to be housed. 
     In this manner, it is possible to shorten the baseline length of the optical module  1   d  even if a structure in which the holder  31   c  of the light emitting module  14   c  is independent from the holder  41   c  of the light receiving module  15   d  is employed similarly to the optical module  1   a.    
     3. Second Embodiment 
     Next, a second embodiment of the present technology will be described with reference to  FIG.  7   . 
       FIG.  7    is a sectional view schematically illustrating an optical module  101  to which the present technology is applied. Note that the same reference signs are applied to the parts corresponding to those of the optical module  1   a  in  FIG.  1    in the drawing, and the description thereof will be appropriately omitted. 
     The optical module  101  is different from the optical module  1   a  in that the optical module  101  includes a substrate  111  and a substrate  112  instead of the substrate  11 . In other words, the optical module  101  has substrates split on the light emitting side and the light receiving side. 
     Specifically, the light emitting element  12  and the light emitting module  14   a  are provided on the substrate  111 . The holder  31   a  of the light emitting module  14   a  is disposed on the substrate  111  to cover the periphery of the light emitting element  12  and is bonded and fixed to the substrate  111  with a light shielding member  113  (for example, a resin having a light shielding property). 
     The light receiving element  13  and the light receiving module  15   a  are provided on the substrate  112 . The holder  41   a  of the light receiving module  15   a  is disposed on the substrate  112  to cover the periphery of the light receiving element  13  and is bonded and fixed to the substrate  112  with a light shielding member  114  (for example, a resin having a light shielding property). 
     In this manner, it is possible to enable the light emitting side and the light receiving side to be separated while maintaining the baseline length to be short. As a result, it is possible to easily change the combination of the module on the light emitting side and the module on the light receiving side, for example. 
     4. Third Embodiment 
     Next, a third embodiment of the present technology will be described with reference to  FIG.  8   . 
       FIG.  8    is a sectional view schematically illustrating an optical module  201  to which the present technology is applied. Note that the same reference signs are applied to the parts corresponding to those of the optical module  1   a  in  FIG.  1    in the drawing, and the description thereof will be appropriately omitted. 
     The optical module  201  is different from the optical module  1   a  in that the optical module  201  includes a substrate  211 , a light emitting module  14   d , and a light receiving module  15   d  instead of the substrate  11 , the light emitting module  14   a , and the light receiving module  15   a.    
     The light emitting module  14   d  includes a light emitting optical system with a similar configuration and is different in that the light emitting module  14   d  includes a holder  31   d  instead of the holder  31   a , as compared with the light emitting module  14   a . The light receiving module  15   d  includes a light receiving optical system with a similar configuration and is different in that the light receiving module  15   d  includes a holder  41   d  instead of the holder  41   a , as compared with the light receiving module  15   a.    
     The holder  31   d  is different from the holder  31   a  in that the lower end extends and is inserted into the substrate  211  as illustrated by the part surrounded by the dotted-line circle in the drawing. As a result, the holder  31   d  is fixed to the substrate  211 , and the periphery of the light emitting element  12  is light-shielded without using the light shielding member  16 . 
     The holder  41   d  is different from the holder  41   a  in that the lower end extends and is inserted into the substrate  211  as illustrated by the part surrounded by the dotted-line circle in the drawing. Therefore, the periphery of the light receiving element  13  is light-shielded without using the light shielding member  16 . 
     5. Fourth Embodiment 
     Next, a fourth embodiment of the present technology will be described with reference to  FIGS.  9  and  10   . 
       FIG.  9    is a sectional view schematically illustrating an optical module  301  to which the present technology is applied.  FIG.  10    is a perspective view schematically illustrating the optical module  301  to which the present technology is applied. Note that the same reference signs are applied to the parts corresponding to those of the optical module  1   a  in  FIG.  2    in the drawing, and description thereof will be appropriately omitted. 
     The optical module  301  is different from the optical module  1   a  in that the optical module  301  includes a light emitting module  14   e  and a light receiving module  15   e  instead of the light emitting module  14   a  and the light receiving module  15   a.    
     The light emitting module  14   e  includes a light emitting optical system with a similar configuration and is different in that the light emitting module  14   e  includes a holder  31   e  instead of the holder  31   a , as compared with the light emitting module  14   a . The light receiving module  15   e  includes a light receiving optical system with a similar configuration and is different in that the light receiving module  15   e  includes a holder  41   e  instead of the holder  41   a , as compared with the light receiving module  15   a.    
     The outer periphery of the holder  31   e  has a rectangular shape, a housing section  31 Ae for housing the light emitting optical system is formed, and also, a rectangular opening portion  31 Be into which the holder  41   a  is inserted is formed beside the housing section  31 Ae. The holder  31   e  is fixed to the substrate  11  with a light shielding member that is similar to the light shielding member  16  in  FIG.  1    after the position is adjusted in accordance with the position of the light emitting element  12  (not illustrated) on the substrate  11 . 
     A housing section  41 Ae that houses the light receiving optical system is formed in the holder  41   e . Also, the holder  41   e  is inserted into the opening portion  31 Be of the holder  31   e . As a result, the relative positions of the light emitting optical system inside the holder  31   e  and the light receiving optical system inside the holder  41   e  are substantially similar to those in the optical module  1   a.    
     Also, the inner periphery of the opening portion  31 Be is lightly larger than the outer periphery of the holder  41   e . Therefore, a clearance is formed between the outer periphery of the holder  41   e  and the inner periphery of the opening portion  31 Be when the holder  41   e  is inserted into the opening portion  31 Be, and the position of the holder  41   e  in the horizontal direction can be adjusted. Then, the holder  41   e  is bonded and fixed to the inside of the opening portion  31 Be by the clearance between the opening portion  31 Be and the holder  41   e  being filled with a light shielding member  311  (for example, a resin having a light shielding property) after the position is adjusted in accordance with the position of the light receiving element  13 . 
     In this manner, it is possible to independently adjust the positions of the holder  31   e  and the holder  41   e  in the optical module  301  as well. 
     Note that the fixation may be achieved by inserting the holder  31   e  into the substrate  11  as in the optical module  201  in  FIG.  8   , for example. 
     6. Modification Examples 
     Hereinafter, modification examples of the embodiments of the present technology described above will be described. 
     The present technology can also be applied to an optical module used for applications other than the distance measuring sensor as long as the optical module includes a light receiving element and a light emitting element. 
     For example, the configurations of the optical elements in the light emitting optical system and the light receiving optical system, for example, the number and the combination of lenses, the combination of optical elements other than lenses, and the like can be changed as needed. 
     For example, the modification examples illustrated in  FIGS.  4  to  6    can be combined as much as possible. 
     For example, the shape of one optical element out of the light emitting optical system and the light receiving optical system can be a D-cut shape, and the shape of the other optical element can be an I-cut shape. For example, the shapes of the optical elements of both the light emitting optical system and the light receiving optical system can be I-cut shapes. For example, the lens section in the light receiving optical system in the optical module  1   d  in  FIG.  6    may also be formed into a D-cut shape similarly to the light emitting optical system. 
     For example, only the holder  41   a  may be fixed to the substrate  11  with the light shielding member  16  in the optical module  1   a  in  FIG.  1   . 
     For example, only the holder  41   a  may be fixed to the substrate  11  with the light shielding member in the optical module  101  in  FIG.  7   . 
     For example, the substrates may be split for the light emitting optical system and the light receiving optical system in the optical module  201  in  FIG.  8    similarly to the optical module  101  in  FIG.  7   . 
     For example, a casing of the light emitting optical system may be inserted into an opening portion of a casing of the light receiving optical system in the optical module  301  in  FIGS.  9  and  10   . 
     Also, the wavelength of the emitted light is not particularly limited in the present technology. 
     7. Application Examples 
     The technology according to the present disclosure (present technology) can be applied to various products. 
     &lt;Examples of Application to In-Vivo Information Acquisition System&gt; 
     For example, the technology according to the present disclosure may be applied to an endoscopic surgical system. 
       FIG.  11    is a block diagram illustrating an example of a schematic configuration of an in-vivo information acquisition system of a patient using a capsule type endoscope, to which the technology according to an embodiment of the present disclosure (present technology) can be applied. 
     The in-vivo information acquisition system  10001  includes a capsule type endoscope  10100  and an external controlling apparatus  10200 . 
     The capsule type endoscope  10100  is swallowed by a patient at the time of inspection. The capsule type endoscope  10100  has an image pickup function and a wireless communication function and successively picks up an image of the inside of an organ such as the stomach or an intestine (hereinafter referred to as in-vivo image) at predetermined intervals while it moves inside of the organ by peristaltic motion for a period of time until it is naturally discharged from the patient. Then, the capsule type endoscope  10100  successively transmits information of the in-vivo image to the external controlling apparatus  10200  outside the body by wireless transmission. 
     The external controlling apparatus  10200  integrally controls operation of the in-vivo information acquisition system  10001 . Further, the external controlling apparatus  10200  receives information of an in-vivo image transmitted thereto from the capsule type endoscope  10100  and generates image data for displaying the in-vivo image on a display apparatus (not depicted) on the basis of the received information of the in-vivo image. 
     In the in-vivo information acquisition system  10001 , an in-vivo image imaged a state of the inside of the body of a patient can be acquired at any time in this manner for a period of time until the capsule type endoscope  10100  is discharged after it is swallowed. 
     A configuration and functions of the capsule type endoscope  10100  and the external controlling apparatus  10200  are described in more detail below. 
     The capsule type endoscope  10100  includes a housing  10101  of the capsule type, in which a light source unit  10111 , an image pickup unit  10112 , an image processing unit  10113 , a wireless communication unit  10114 , a power feeding unit  10115 , a power supply unit  10116  and a control unit  10117  are accommodated. 
     The light source unit  10111  includes a light source such as, for example, a light emitting diode (LED) and irradiates light on an image pickup field-of-view of the image pickup unit  10112 . 
     The image pickup unit  10112  includes an image pickup element and an optical system including a plurality of lenses provided at a preceding stage to the image pickup element. Reflected light (hereinafter referred to as observation light) of light irradiated on a body tissue which is an observation target is condensed by the optical system and introduced into the image pickup element. In the image pickup unit  10112 , the incident observation light is photoelectrically converted by the image pickup element, by which an image signal corresponding to the observation light is generated. The image signal generated by the image pickup unit  10112  is provided to the image processing unit  10113 . 
     The image processing unit  10113  includes a processor such as a central processing unit (CPU) or a graphics processing unit (GPU) and performs various signal processes for an image signal generated by the image pickup unit  10112 . The image processing unit  10113  provides the image signal for which the signal processes have been performed thereby as RAW data to the wireless communication unit  10114 . 
     The wireless communication unit  10114  performs a predetermined process such as a modulation process for the image signal for which the signal processes have been performed by the image processing unit  10113  and transmits the resulting image signal to the external controlling apparatus  10200  through an antenna  10114 A. Further, the wireless communication unit  10114  receives a control signal relating to driving control of the capsule type endoscope  10100  from the external controlling apparatus  10200  through the antenna  10114 A. The wireless communication unit  10114  provides the control signal received from the external controlling apparatus  10200  to the control unit  10117 . 
     The power feeding unit  10115  includes an antenna coil for power reception, a power regeneration circuit for regenerating electric power from current generated in the antenna coil, a voltage booster circuit and so forth. The power feeding unit  10115  generates electric power using the principle of non-contact charging. 
     The power supply unit  10116  includes a secondary battery and stores electric power generated by the power feeding unit  10115 . In  FIG.  11   , in order to avoid complicated illustration, an arrow mark indicative of a supply destination of electric power from the power supply unit  10116  and so forth are omitted. However, electric power stored in the power supply unit  10116  is supplied to and can be used to drive the light source unit  10111 , the image pickup unit  10112 , the image processing unit  10113 , the wireless communication unit  10114 , and the control unit  10117 . 
     The control unit  10117  includes a processor such as a CPU and suitably controls driving of the light source unit  10111 , the image pickup unit  10112 , the image processing unit  10113 , the wireless communication unit  10114  and the power feeding unit  10115  in accordance with a control signal transmitted thereto from the external controlling apparatus  10200 . 
     The external controlling apparatus  10200  includes a processor such as a CPU or a GPU, a microcomputer, a control board or the like in which a processor and a storage element such as a memory are mixedly incorporated. The external controlling apparatus  10200  transmits a control signal to the control unit  10117  of the capsule type endoscope  10100  through an antenna  10200 A to control operation of the capsule type endoscope  10100 . In the capsule type endoscope  10100 , an irradiation condition of light upon an observation target of the light source unit  10111  can be changed, for example, in accordance with a control signal from the external controlling apparatus  10200 . Further, an image pickup condition (for example, a frame rate, an exposure value or the like of the image pickup unit  10112 ) can be changed in accordance with a control signal from the external controlling apparatus  10200 . Further, the substance of processing by the image processing unit  10113  or a condition for transmitting an image signal from the wireless communication unit  10114  (for example, a transmission interval, a transmission image number or the like) may be changed in accordance with a control signal from the external controlling apparatus  10200 . 
     Further, the external controlling apparatus  10200  performs various image processes for an image signal transmitted thereto from the capsule type endoscope  10100  to generate image data for displaying a picked up in-vivo image on the display apparatus. As the image processes, various signal processes can be performed such as, for example, a development process (demosaic process), an image quality improving process (bandwidth enhancement process, a super-resolution process, a noise reduction (NR) process and/or image stabilization process) and/or an enlargement process (electronic zooming process). The external controlling apparatus  10200  controls driving of the display apparatus to cause the display apparatus to display a picked up in-vivo image on the basis of generated image data. Alternatively, the external controlling apparatus  10200  may also control a recording apparatus (not depicted) to record generated image data or control a printing apparatus (not depicted) to output generated image data by printing. 
     An example of the in-vivo information acquisition system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the image pickup unit  10112  among the configurations described above. Specifically, the present invention can be applied to a distance measuring sensor used for focus control of the image pickup unit  10112 , for example. As a result, it is possible to further reduce the size of the capsule type endoscope  10100 , for example. 
     &lt;Examples of Application to Mobile Body&gt; 
     For example, the technology according to the present disclosure may be realized as a device mounted on any type of mobile body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility, an airplane, a drone, a ship, or a robot. 
       FIG.  12    is a block diagram illustrating a schematic configuration example of a vehicle control system as an example of a mobile body control system to which the technology according to the present disclosure can be applied. 
     The vehicle control system  12000  includes a plurality of electronic control units connected to each other via a communication network  12001 . In the example depicted in  FIG.  12   , the vehicle control system  12000  includes a driving system control unit  12010 , a body system control unit  12020 , an outside-vehicle information detecting unit  12030 , an in-vehicle information detecting unit  12040 , and an integrated control unit  12050 . In addition, a microcomputer  12051 , a sound/image output section  12052 , and a vehicle-mounted network interface (I/F)  12053  are illustrated as a functional configuration of the integrated control unit  12050 . 
     The driving system control unit  12010  controls the operation of devices related to the driving system of the vehicle in accordance with various kinds of programs. For example, the driving system control unit  12010  functions as a control device for a driving force generating device for generating the driving force of the vehicle, such as an internal combustion engine, a driving motor, or the like, a driving force transmitting mechanism for transmitting the driving force to wheels, a steering mechanism for adjusting the steering angle of the vehicle, a braking device for generating the braking force of the vehicle, and the like. 
     The body system control unit  12020  controls the operation of various kinds of devices provided to a vehicle body in accordance with various kinds of programs. For example, the body system control unit  12020  functions as a control device for a keyless entry system, a smart key system, a power window device, or various kinds of lamps such as a headlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or the like. In this case, radio waves transmitted from a mobile device as an alternative to a key or signals of various kinds of switches can be input to the body system control unit  12020 . The body system control unit  12020  receives these input radio waves or signals, and controls a door lock device, the power window device, the lamps, or the like of the vehicle. 
     The outside-vehicle information detecting unit  12030  detects information about the outside of the vehicle including the vehicle control system  12000 . For example, the outside-vehicle information detecting unit  12030  is connected with an imaging section  12031 . The outside-vehicle information detecting unit  12030  makes the imaging section  12031  image an image of the outside of the vehicle, and receives the imaged image. On the basis of the received image, the outside-vehicle information detecting unit  12030  may perform processing of detecting an object such as a human, a vehicle, an obstacle, a sign, a character on a road surface, or the like, or processing of detecting a distance thereto. 
     The imaging section  12031  is an optical sensor that receives light, and which outputs an electric signal corresponding to a received light amount of the light. The imaging section  12031  can output the electric signal as an image, or can output the electric signal as information about a measured distance. In addition, the light received by the imaging section  12031  may be visible light, or may be invisible light such as infrared rays or the like. 
     The in-vehicle information detecting unit  12040  detects information about the inside of the vehicle. The in-vehicle information detecting unit  12040  is, for example, connected with a driver state detecting section  12041  that detects the state of a driver. The driver state detecting section  12041 , for example, includes a camera that images the driver. On the basis of detection information input from the driver state detecting section  12041 , the in-vehicle information detecting unit  12040  may calculate a degree of fatigue of the driver or a degree of concentration of the driver, or may determine whether the driver is dozing. 
     The microcomputer  12051  can calculate a control target value for the driving force generating device, the steering mechanism, or the braking device on the basis of the information about the inside or outside of the vehicle which information is obtained by the outside-vehicle information detecting unit  12030  or the in-vehicle information detecting unit  12040 , and output a control command to the driving system control unit  12010 . For example, the microcomputer  12051  can perform cooperative control intended to implement functions of an advanced driver assistance system (ADAS) which functions include collision avoidance or shock mitigation for the vehicle, following driving based on a following distance, vehicle speed maintaining driving, a warning of collision of the vehicle, a warning of deviation of the vehicle from a lane, or the like. 
     In addition, the microcomputer  12051  can perform cooperative control intended for automated driving, which makes the vehicle to travel automatedly without depending on the operation of the driver, or the like, by controlling the driving force generating device, the steering mechanism, the braking device, or the like on the basis of the information about the outside or inside of the vehicle which information is obtained by the outside-vehicle information detecting unit  12030  or the in-vehicle information detecting unit  12040 . 
     In addition, the microcomputer  12051  can output a control command to the body system control unit  12020  on the basis of the information about the outside of the vehicle which is obtained by the outside-vehicle information detecting unit  12030 . For example, the microcomputer  12051  can perform cooperative control intended to prevent a glare by controlling the headlamp so as to change from a high beam to a low beam, for example, in accordance with the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detecting unit  12030 . 
     The sound/image output section  12052  transmits an output signal of at least one of a sound and an image to an output device capable of visually or auditorily notifying information to an occupant of the vehicle or the outside of the vehicle. In the example of  FIG.  12   , an audio speaker  12061 , a display section  12062 , and an instrument panel  12063  are illustrated as the output device. The display section  12062  may, for example, include at least one of an on-board display and a head-up display. 
       FIG.  13    is a diagram illustrating an example of the installation position of the imaging section  12031 . 
     In  FIG.  13   , the imaging section  12031  includes imaging sections  12101 ,  12102 ,  12103 ,  12104 , and  12105 . 
     The imaging sections  12101 ,  12102 ,  12103 ,  12104 , and  12105  are, for example, disposed at positions on a front nose, sideview mirrors, a rear bumper, and a back door of the vehicle  12100  as well as a position on an upper portion of a windshield within the interior of the vehicle. The imaging section  12101  provided to the front nose and the imaging section  12105  provided to the upper portion of the windshield within the interior of the vehicle obtain mainly an image of the front of the vehicle  12100 . The imaging sections  12102  and  12103  provided to the sideview mirrors obtain mainly an image of the sides of the vehicle  12100 . The imaging section  12104  provided to the rear bumper or the back door obtains mainly an image of the rear of the vehicle  12100 . The imaging section  12105  provided to the upper portion of the windshield within the interior of the vehicle is used mainly to detect a preceding vehicle, a pedestrian, an obstacle, a signal, a traffic sign, a lane, or the like. 
     Note that  FIG.  13    illustrates an example of image capturing ranges of the imaging sections  12101  to  12104 . An imaging range  12111  represents the imaging range of the imaging section  12101  provided to the front nose. Imaging ranges  12112  and  12113  respectively represent the imaging ranges of the imaging sections  12102  and  12103  provided to the sideview mirrors. An imaging range  12114  represents the imaging range of the imaging section  12104  provided to the rear bumper or the back door. A bird&#39;s-eye image of the vehicle  12100  as viewed from above is obtained by superimposing image data imaged by the imaging sections  12101  to  12104 , for example. 
     At least one of the imaging sections  12101  to  12104  may have a function of obtaining distance information. For example, at least one of the imaging sections  12101  to  12104  may be a stereo camera constituted of a plurality of imaging elements, or may be an imaging element having pixels for phase difference detection. 
     For example, the microcomputer  12051  can determine a distance to each three-dimensional object within the imaging ranges  12111  to  12114  and a temporal change in the distance (relative speed with respect to the vehicle  12100 ) on the basis of the distance information obtained from the imaging sections  12101  to  12104 , and thereby extract, as a preceding vehicle, a nearest three-dimensional object in particular that is present on a traveling path of the vehicle  12100  and which travels in substantially the same direction as the vehicle  12100  at a predetermined speed (for example, equal to or more than 0 km/hour). Further, the microcomputer  12051  can set a following distance to be maintained in front of a preceding vehicle in advance, and perform automatic brake control (including following stop control), automatic acceleration control (including following start control), or the like. It is thus possible to perform cooperative control intended for automated driving that makes the vehicle travel automatedly without depending on the operation of the driver or the like. 
     For example, the microcomputer  12051  can classify three-dimensional object data on three-dimensional objects into three-dimensional object data of a two-wheeled vehicle, a standard-sized vehicle, a large-sized vehicle, a pedestrian, a utility pole, and other three-dimensional objects on the basis of the distance information obtained from the imaging sections  12101  to  12104 , extract the classified three-dimensional object data, and use the extracted three-dimensional object data for automatic avoidance of an obstacle. For example, the microcomputer  12051  identifies obstacles around the vehicle  12100  as obstacles that the driver of the vehicle  12100  can recognize visually and obstacles that are difficult for the driver of the vehicle  12100  to recognize visually. Then, the microcomputer  12051  determines a collision risk indicating a risk of collision with each obstacle. In a situation in which the collision risk is equal to or higher than a set value and there is thus a possibility of collision, the microcomputer  12051  outputs a warning to the driver via the audio speaker  12061  or the display section  12062 , and performs forced deceleration or avoidance steering via the driving system control unit  12010 . The microcomputer  12051  can thereby assist in driving to avoid collision. 
     At least one of the imaging sections  12101  to  12104  may be an infrared camera that detects infrared rays. The microcomputer  12051  can, for example, recognize a pedestrian by determining whether or not there is a pedestrian in imaged images of the imaging sections  12101  to  12104 . Such recognition of a pedestrian is, for example, performed by a procedure of extracting characteristic points in the imaged images of the imaging sections  12101  to  12104  as infrared cameras and a procedure of determining whether or not it is the pedestrian by performing pattern matching processing on a series of characteristic points representing the contour of the object. When the microcomputer  12051  determines that there is a pedestrian in the imaged images of the imaging sections  12101  to  12104 , and thus recognizes the pedestrian, the sound/image output section  12052  controls the display section  12062  so that a square contour line for emphasis is displayed so as to be superimposed on the recognized pedestrian. The sound/image output section  12052  may also control the display section  12062  so that an icon or the like representing the pedestrian is displayed at a desired position. 
     An example of the vehicle control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to a distance measuring sensor, an object sensor, and the like provided in a sensor section (not illustrated) that can be connected to the outside-vehicle information detecting unit  12030  among the configurations described above. As a result, it is possible to further reduce the size of the sensor section, for example. 
     8. Others 
     The embodiments of the present technology are not limited to the aforementioned embodiments, and various modifications can be made without departing from the gist of the present technology. 
     &lt;Combination Examples of Configuration&gt; 
     The present technology can also have the following configurations. 
     (1) An optical module including: 
     a substrate; 
     a light emitting element that is disposed on the substrate; 
     a light receiving element that is disposed on the substrate at a predetermined interval from the light emitting element; 
     a first casing that is disposed on the substrate and surrounds a periphery of the light emitting element; 
     a second casing that is disposed on the substrate and surrounds a periphery of the light receiving element; 
     a light emitting lens that is housed in the first casing and is disposed on an optical axis of the light emitting element; and 
     a light receiving lens that is housed in the second casing and is disposed on an optical axis of the light receiving element, 
     in which a first diameter of one lens out of the light emitting lens and the light receiving lens in a first direction toward an optical axis of another lens with reference to an optical axis of the one lens is shorter than a second diameter of the one lens in a second direction that is orthogonal to the first direction. 
     (2) 
     The optical module according to (1) described above, 
     in which the first casing is fixed to the substrate with a member having a light shielding property. 
     (3) 
     The optical module according (2) described above, 
     in which the first casing is further fixed to the substrate with a member having a light shielding property. 
     (4) 
     The optical module according to (1) described above, 
     in which the first casing is inserted into the substrate. 
     (5) 
     The optical module according to (4) described above, 
     in which the second casing is further inserted into the substrate. 
     (6) 
     The optical module according to any one of (1) to (5) described above, 
     in which the substrate on which the light emitting element and the first casing are disposed and the substrate on which the light receiving element and the second casing are disposed are different from each other. 
     (7) 
     The optical module according to any one of (1) to (5) described above, 
     in which an opening portion of one casing out of the first casing and the second casing allows another casing to be inserted thereinto with a clearance between an outer periphery of the another casing and an inner periphery of the opening portion. 
     (8) 
     The optical module according to (7) described above, 
     in which the another casing is fixed to the opening portion with a member having a light shielding property, with which the clearance is filled. 
     (9) 
     The optical module according to any one of (1) to (8) described above, 
     in which the optical axis of the one lens is biased in the first direction from a center of the one lens. 
     (10) 
     The optical module according to (9) described above, 
     in which the one lens has a D-cut shape that has a linear shape on a side on which the one lens is adjacent to the another lens. 
     (11) 
     The optical module according to (9) described above, 
     in which an outer periphery of the one lens has a rectangular shape. 
     (12) 
     The optical module according to any one of (1) to (8) described above, 
     in which the one lens has an I-cut shape that has linear shapes on a side on which the one lens is adjacent to the another lens and a side opposite to the side on which the one lens is adjacent to the another lens. 
     (13) 
     The optical module according to any one of (1) to (12) described above, 
     in which a diameter of the another lens in a third direction toward the optical axis of the one lens with reference to the optical axis of the another lens is shorter than a diameter of the another lens in a fourth direction that is orthogonal to the third direction. 
     (14) 
     The optical module according to any one of (1) to (13) described above, 
     in which the first diameter is equal to or greater than an effective diameter of the one lens. 
     Note that the effects described in the present specification are illustrated just as examples and are not limited thereto and there may be other effects. 
     REFERENCE SIGNS LIST 
     
         
           1   a  to  1   d  Optical module 
           11  Substrate 
           12  Light emitting element 
           13  Light receiving element 
           14   a  to  14   e  Light emitting module 
           15   a  to  15   e  Light receiving module 
           16  Light shielding member 
           31   a  to  31   e  Holder 
           41   a  to  41   e  Holder 
           42   a  to  42   c  Bandpass filter 
           101  Optical module 
           111 ,  112  Substrate 
           113 ,  114  Light shielding member 
           201  Optical module 
           211  Substrate 
           301  Optical module 
         LTa to LTc Light emitting lens group 
         LT 1   a , LT 1   c  Lens 
         LRa to LRc Light receiving lens group 
         LR 1   a , LR 1   c  Lens