JP6415129B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus including a plurality of optical members and an imaging element that receives subject light through the plurality of optical members.

  Conventionally, medical diagnosis using an electronic endoscope has been performed in the medical field. For example, an electronic endoscope called a scope is provided with an insertion portion that is inserted into a patient's body. An imaging device having a plurality of optical members and an imaging element that receives and images subject light through the plurality of optical members is provided in an internal space of the insertion portion distal end that is the distal end portion of the insertion portion. . The plurality of optical members are, for example, an observation optical system, a prism, and a cover glass that protects the imaging surface of the imaging element, and the optical members adjacent to each other are bonded to each other with an adhesive layer.

  In recent years, image sensors used in electronic endoscopes have become highly precise, and the mounting accuracy of image sensors has become stricter than ever. The same applies to each optical member provided in the vicinity of the image sensor, and due to the fact that it is close to the image pickup surface (also referred to as the imaging surface) of the image sensor, there is a small degree of foreign matter, perpendicularity to the optical axis, etc. It becomes a problem. For this reason, when optical members are bonded to each other, it is necessary to ensure the parallelism between the two with high accuracy. However, when optical members are directly bonded to each other with an adhesive layer, the parallelism is caused by variations in the thickness of the adhesive layer. Will not stabilize and will vary. As a result, it is not possible to cope with a further increase in the mounting accuracy of the optical member.

  Patent Documents 1 to 3 disclose an image pickup apparatus in which a light shielding film is provided between optical members adjacent to each other, and the optical members adjacent to each other are bonded with an adhesive layer via the light shielding film. The light shielding films described in Patent Documents 1 to 3 are formed in a frame shape so as to pass subject light received in the effective pixel area of the image sensor. Since the light-shielding film functions as a so-called spacer, variations in parallelism can be suppressed.

  In Patent Document 4, a concave portion having an opening larger in area than the effective pixel area of the image sensor is formed on the bottom surface of the prism so that the bottom surface of the prism and the image sensor are in direct contact with each other without an adhesive. An image pickup apparatus is disclosed in which a prism and an image pickup element are bonded with an adhesive applied to a side surface of a recess. By bonding the optical members using the technique described in Patent Document 4, the variation in parallelism can be suppressed.

  Patent Document 5 discloses a method of manufacturing an image pickup apparatus having a prism and an image pickup element bonded to each other by using a wafer level chip size package (W-CSP) method. Specifically, an image pickup device substrate on which a plurality of image pickup devices are formed and a transparent substrate are bonded with an adhesive layer to produce a bonded substrate, and the bonded transparent substrate is subjected to dicing or the like to each image pickup device. After producing the corresponding prisms, a plurality of image pickup devices are manufactured by dividing the bonding substrate into pieces for each image pickup element. The adhesive layer has an opening that exposes an effective pixel area of each image sensor, and is formed in a frame shape when the bonded substrate is separated. By using the W-CSP method described in Patent Document 5 to manufacture a plurality of optical members bonded together and simultaneously, variations in parallelism can be suppressed.

  Patent Document 6 discloses an imaging apparatus having a structure in which a cover glass and a prism are bonded with an adhesive layer through a light shielding film provided between the prism and the cover glass of the imaging element. The light shielding film is formed in a frame shape like the light shielding films described in Patent Documents 1 to 3. In addition, the light shielding film is formed with a groove for discharging bubbles entrained during bonding. Also in the imaging apparatus of Patent Document 6, the light shielding film functions as a so-called spacer, so that variations in parallelism can be suppressed.

JP 2013-244252 A Japanese Patent No. 3233483 Japanese Patent Laid-Open No. 4-120508 JP 2011-234214 A JP 2012-29049 A Japanese Patent Laid-Open No. 5-190823

  However, in the imaging devices described in Patent Documents 1 to 3, since the light-shielding film that functions as a spacer is formed in a frame shape, the adhesive is applied when an adhesive is applied between optical members to form an adhesive layer. There arises a problem that it is difficult to discharge the contained bubbles and excess adhesive.

  Further, in the imaging device described in Patent Document 4, since it is necessary to form a recess by performing special processing on the prism, the manufacturing cost of the imaging device increases.

  Further, in the method for manufacturing an imaging device described in Patent Document 5, since it is necessary to use the W-CSP method, the manufacturing process becomes large, and in the case of manufacturing a small quantity of various types of imaging devices, the same as in Patent Document 4 above. However, there is a problem that the manufacturing cost increases.

  Further, unlike the light shielding films described in Patent Documents 1 to 3, a groove for discharging bubbles contained in the adhesive and excess adhesive is formed in the light shielding film of the imaging device described in Patent Document 6. However, since the width of the groove is narrow, bubbles and excess adhesive cannot be discharged sufficiently. If the width of the groove is increased, subject light that needs to be blocked by the light shielding film cannot be blocked by the light shielding film. Therefore, in the imaging device described in Patent Document 6, the width of the groove of the light shielding film is not increased. Can not.

  The present invention has been made in view of such circumstances, and an imaging apparatus capable of improving the mounting accuracy of an optical member and discharging the bubbles and excess adhesive contained in the adhesive at low cost. The purpose is to provide.

  An imaging apparatus for achieving an object of the present invention includes a plurality of optical members and an imaging element having a rectangular effective pixel area that receives subject light through the plurality of optical members. In the imaging device in which the first optical member and the second optical member adjacent to each other are bonded with an adhesive layer, the first optical member and the second optical member are provided in a space between the first optical member and the second optical member. Is a spacer that makes the interval between the optical member and the second optical member uniform, and is a light transmission that projects the effective pixel area of the rectangular imaging element in a space through which subject light received by the effective pixel area passes. A spacer having a structure in which at least one side of the region is opened is provided.

  According to the present invention, it is possible to discharge air bubbles and excess adhesive contained in the adhesive from at least one open side of the light transmission region. Further, when manufacturing the imaging device, it is not necessary to perform special processing on an optical member such as a prism or use the W-CSP method, and it is only necessary to provide a spacer. The device can be manufactured. Furthermore, when bonding the first optical member and the second optical member, by providing a spacer between them, it is possible to ensure parallelism with high accuracy simply by pressing one of them against the other. .

  In the imaging device according to another aspect of the present invention, when the area used for image display in the effective pixel area is an image area, and the area inside the effective pixel area and outside the image area is a difference area, The difference area includes a specific area that is a specific area and has a larger area than the area other than the specific area in the difference area, and the spacer is provided in a corresponding area corresponding to the specific area in the space. ing. Since the specific area in the effective pixel area is not used for image display, even if a spacer exists in the corresponding area corresponding to the specific area, the image display is not affected. As a result, the spacer can be provided in the space without affecting the image display.

  In the imaging apparatus according to another aspect of the present invention, the difference area includes three or more specific areas, and the spacer is provided independently for each corresponding area. Spacers can be provided in the space without affecting the image display.

  In the imaging device according to another aspect of the present invention, the specific region is a region corresponding to the four corner portions of the difference area. Since the area of the four corner portions of the difference area is larger than the area of the other region other than the four corner portions, the spacers can be easily arranged and formed in the corresponding region.

  In the imaging device according to another aspect of the present invention, the spacer has a structure in which at least two sides of the light transmission region are open. Thereby, the bubble contained in an adhesive agent and the excess adhesive agent can be discharged | emitted from at least 2 edge | sides by which the light transmission area | region is open | released.

  In the imaging device according to another aspect of the present invention, the spacer has a structure in which two opposite sides of the light transmission region are opened and the other two sides are closed. Thereby, the bubble contained in an adhesive agent and the excess adhesive agent can be discharged | emitted from two mutually opposing sides of a light transmissive area | region.

  In the imaging apparatus according to another aspect of the present invention, the first optical member is a cover glass that covers an imaging surface on which an effective pixel area of the imaging element is formed, and the second optical member is parallel to the imaging surface. This is a prism that bends a subject light incident from a lens barrel having a simple optical axis and makes it incident on a cover glass. It is possible to improve the mounting accuracy of the cover glass and the prism in the imaging apparatus and to discharge the bubbles and the excess adhesive contained in the adhesive that bonds them together at low cost.

  In the imaging device according to another aspect of the present invention, the effective pixel area is formed on the end of the imaging surface on the lens barrel side, and the prism is an adhesive layer on the end of the cover glass on the lens barrel side. The incident surface on which the subject light is bonded is located closer to the lens barrel side than the end portion of the cover glass on the lens barrel side, and the spacer has at least one side of the light transmission region on the lens barrel side. It has an open structure. As a result, the mounting position of the lens barrel can be shifted to the image pickup element side as compared with the prior art, so that the prism can be made smaller than before. As a result, the imaging device can be reduced in size.

  In the imaging apparatus according to another aspect of the present invention, the first optical member is a cover glass that covers an imaging surface on which an effective pixel area of the imaging element is formed, and the second optical member is an imaging of the cover glass. The filter is provided on the side opposite to the surface facing the element. It is possible to improve the mounting accuracy of the cover glass and the filter in the imaging apparatus and to discharge bubbles and excess adhesive contained in the adhesive that bonds them together at low cost.

  In the imaging device according to another aspect of the present invention, the spacer is provided inside the outer periphery of each of the first optical member and the second optical member in the space, and the adhesive layer includes the outer periphery, the spacer, and the spacer. It is provided inside the outer periphery including between. Thereby, the space in the vicinity of the spacer and the thickness of the adhesive layer can be made uniform.

  In the imaging device according to another aspect of the present invention, the spacer is formed on the surface of the second optical member facing the first optical member by plating or vapor deposition. Thereby, the spacer of arbitrary shapes can be formed.

  The imaging device of the present invention can improve the mounting accuracy of the optical member and discharge bubbles and excess adhesive contained in the adhesive at low cost.

It is an external appearance perspective view of an endoscope apparatus. It is a front view of the insertion part tip part of an electronic endoscope. It is sectional drawing of the flexible tube part of an electronic endoscope. It is sectional drawing of the insertion part front-end | tip part of an electronic endoscope. It is the side view and front view of a cover glass and an image pick-up element. (A) is sectional drawing of the principal part of the imaging device of 1st Embodiment, (B) is sectional drawing which follows the A1-A1 line of (A), (C) is A2-A2 of (A). It is sectional drawing which follows a line. It is explanatory drawing for demonstrating the effect of an imaging device. (A) is sectional drawing of the principal part of the imaging device of 2nd Embodiment, (B) is sectional drawing which follows the A1-A1 line of (A), (C) is A2-A2 of (A). It is sectional drawing which follows a line. It is explanatory drawing for demonstrating the specific effect of the imaging device of 2nd Embodiment. (A) is sectional drawing of the principal part of the imaging device of 3rd Embodiment, (B) is sectional drawing which follows the A1-A1 line of (A). It is explanatory drawing for demonstrating the modification of the imaging device of 3rd Embodiment. (A) is sectional drawing of the principal part of the imaging device of 4th Embodiment, (B) is sectional drawing which follows the A1-A1 line of (A). (A) is sectional drawing of the principal part of the imaging device of 5th Embodiment, (B) is sectional drawing which follows the A1-A1 line of (A). FIG. 14 is an enlarged view of a portion surrounded by a dotted circle Q in FIG. It is explanatory drawing for demonstrating the modification of the imaging device of 5th Embodiment. It is sectional drawing of the imaging device of 6th Embodiment. It is the schematic of a capsule system provided with the imaging device of this invention. It is the schematic of the capsule system of other embodiment. It is explanatory drawing for demonstrating the image pick-up element and board | substrate of other embodiment.

  Hereinafter, an endoscope apparatus according to the present invention will be described with reference to the accompanying drawings.

[Entire configuration of endoscope apparatus]
FIG. 1 is an external perspective view of an endoscope apparatus (also referred to as an endoscope system) 10. The endoscope apparatus 10 includes an electronic endoscope 11, a light source apparatus 12, a processor apparatus 13, a monitor 14, and an air / water supply apparatus 15 as a scope (here, a flexible endoscope) that images an observation site in a patient. Etc.

  The light source device 12 supplies illumination light for illuminating the observation site to the electronic endoscope 11. The processor device 13 generates image data of the observation region based on the imaging signal obtained by the electronic endoscope 11 and outputs the image data to the monitor 14. The monitor 14 displays an observation image of the observation site based on the image data input from the processor device 13. The air / water supply device 15 is built in the light source device 12, and is provided outside the light source device 12 with an air supply pump 15a that generates a delivery pressure of fluid such as air and cleaning water, and a cleaning water tank that stores cleaning water. 15b.

  The electronic endoscope 11 is connected to a flexible insertion portion 16 to be inserted into a patient's body and a proximal end portion of the insertion portion 16, and is used for gripping the electronic endoscope 11 and operating the insertion portion 16. An operation unit 17 and a universal cord 18 that connects the operation unit 17 to the light source device 12 and the processor device 13 are provided.

  As will be described in detail later, the insertion portion distal end portion 16a that is the distal end portion of the insertion portion 16 incorporates an observation optical system, an imaging element, and the like used for illumination of the observation portion and photographing. A bendable bending portion 16b is connected to the rear end of the insertion portion distal end portion 16a. A flexible tube portion 16c having flexibility is connected to the rear end of the curved portion 16b.

  FIG. 2 is a front view of the insertion portion distal end portion 16a. As shown in FIG. 2, an observation window 21, an illumination window 22, a forceps outlet 23, and an ejection nozzle 24 are provided on the distal end cover 20 of the insertion portion distal end portion 16 a. In the back of the observation window 21, the above-described observation optical system, image pickup device, and the like are provided. Two illumination windows 22 are arranged at symmetrical positions with respect to the observation window 21 and irradiate the observation site in the patient's body with illumination light supplied from the light source device 12. The forceps outlet 23 communicates with a forceps inlet 37 (see FIG. 1) of the operation unit 17. The injection nozzle 24 injects air and cleaning water supplied from the air / water supply device 15 toward the observation window 21 to remove dirt attached to the observation window 21.

  FIG. 3 is a cross-sectional view of the flexible tube portion 16c. As shown in FIG. 3, a plurality of built-in objects such as a light guide 28, forceps channel 29, air / water channel 30 and cable 31 are loosely inserted in the flexible tube portion 16c. The light guide 28 guides light from the light source device 12 to the illumination window 22. The forceps channel 29 communicates the forceps outlet 23 and the forceps inlet 37. The air / water supply channel 30 sends the air and washing water supplied from the air / water supply device 15 to the spray nozzle 24. The cable 31 electrically connects the processor device 13 and the image pickup device of the electronic endoscope 11.

  Returning to FIG. 1, the operation unit 17 is provided with an angle knob 35, an operation button 36, a forceps inlet 37, and the like. The angle knob 35 is rotated when adjusting the bending direction and the bending amount of the bending portion 16b. The operation button 36 is used for various operations such as air / water supply and suction. The forceps inlet 37 communicates with the forceps channel 29.

  The universal cord 18 incorporates the light guide 28, the air / water channel 30 and the cable 31 described above. A connector portion 25 a connected to the light source device 12 and the air / water supply device 15 and a connector portion 25 b connected to the processor device 13 are provided at the distal end portion of the universal cord 18. Thereby, illumination light is supplied from the light source device 12 to the light guide 28 via the connector portion 25a, and air and water are supplied from the air / water supply device 15 to the air / water supply channel 30. In addition, an imaging signal obtained by the electronic endoscope 11 is input to the processor device 13 via the connector unit 25b.

  FIG. 4 is a cross-sectional view of the insertion portion distal end portion 16a. As shown in FIG. 4, the insertion portion distal end portion 16 a includes a tubular body 41, a distal end cover 20 that closes the opening on the distal end side of the tubular body 41, and rubber that covers the outer periphery of the distal end cover 20 and the tubular body 41. 42 and various built-in objects built in the internal space of the insertion portion distal end portion 16a.

  The light guide 28 (not shown in FIG. 4), the forceps channel 29, the air / water supply channel 30 (not shown in FIG. 4), the cable 31, and the like are inserted into the internal space of the insertion portion distal end portion 16a. In addition, the imaging device 45 of the present invention is incorporated. In addition, although illustration is abbreviate | omitted, the internal space of the insertion part front-end | tip part 16a is filled with resin, and various built-in things in an internal space are being fixed with this resin.

  A forceps channel 29 is connected to the forceps outlet 23 of the tip cover 20. Although not shown in FIG. 4, an illumination lens is incorporated behind the illumination window 22, and the exit end of the light guide 28 faces the illumination lens. Although not shown in FIG. 4, an air / water supply channel 30 is connected to the injection nozzle 24. One end of each of the light guide 28, the forceps channel 29, and the air / water supply channel 30 is fixed to the tip cover 20, and the other end passes through the inside of the bending portion 16b, the flexible tube portion 16c, the operation portion 17, and the like. The light source device 12, the forceps inlet 37, and the air / water supply device 15 are respectively connected.

[Configuration of Imaging Device of First Embodiment]
An imaging device 45 is disposed in the back of the observation window 21. The imaging device 45 roughly includes an observation optical system (also referred to as an objective optical system) 50, a prism 51, a cover glass 52, an imaging element 53, and a substrate 54. Here, the prism 51 and the cover glass 52 correspond to an embodiment of the plurality of optical members of the present invention. In the present embodiment, the cover glass 52 and the image sensor 53 are formed in a rectangular shape, and the substrate 54 is formed in a rectangular shape, but the shapes are not particularly limited.

  The observation optical system 50 is housed in a lens barrel 50 a fixed to the observation window 21 of the tip cover 20. The observation optical system 50 causes subject light (also referred to as image light) from the observation region that has entered from the observation window 21 to enter the prism 51. Note that the symbol “OA” in the figure is the optical axis of the observation optical system 50 and is parallel to the imaging surface of the imaging element 53.

  The prism 51 corresponds to an embodiment of the second optical member of the present invention, and the subject light incident from the observation optical system 50 is bent 90 ° inside and emitted toward the image sensor 53. Thereby, the subject light at the observation site is imaged on the imaging surface of the imaging element 53 through the cover glass 52. The subject light incident surface of the prism 51 is bonded and fixed to the lens barrel 50a.

  The cover glass 52 corresponds to an embodiment of the first optical member of the present invention. One surface of the cover glass 52 is bonded and fixed to the imaging surface of the imaging element 53 via a spacer 60 (see FIG. 5), and the other surface is bonded and fixed to the subject light emission surface of the prism 51. Thereby, the imaging surface of the imaging element 53 is protected by the cover glass 52, and the imaging element 53 is fixed to the prism 51 via the cover glass 52. The “cover glass” referred to in this specification includes not only glass but also those formed of a transparent resin.

  FIG. 5 is a side view and a front view of the cover glass 52 and the image sensor 53 (the prism 52 is not shown). The image sensor 53 is a complementary metal oxide semiconductor (CMOS) type image sensor or a CCD (charge coupled device) type image sensor. When the image sensor 53 is a CMOS type, a so-called back-illuminated CMOS image sensor may be used.

  A plurality of pixels configured by a plurality of photoelectric conversion elements (photodiodes) PD arranged two-dimensionally are formed on the imaging surface of the imaging element 53. The image sensor 53 receives subject light incident through the cover glass 52, converts it into an electrical image signal, and outputs it.

  Further, in the central portion (including the substantially central portion) of the image pickup surface of the image pickup device 53, a rectangular (including substantially rectangular) effective pixel in which a pixel signal is used as a signal actually captured on the image pickup surface. Area 61 is formed. Within this effective pixel area 61 and inside the imaging area 63, a rectangular (including a substantially rectangular) image area 64 is included. The imaging area 63 is an area of subject light (optical image) that is imaged on the imaging surface of the imaging element 53 through the observation optical system 50, the prism 51, and the like. In the present embodiment, the imaging area 63 has a circular shape (other shapes are possible). is there. The image area 64 is an area used for image display in the effective pixel area 61, and is an area obtained by removing a portion used for image processing and the like from the effective pixel area 61 and a margin of several pixels. Accordingly, the pixels in the difference area 67 that is inside the effective pixel area 61 and outside the image area 64 are not used for image display. The shape of the image area 64 is not limited to a rectangular shape, and may take various shapes such as a polygonal shape such as a hexagonal shape and an octagonal shape, or a circular shape.

  In addition, a wire bond pad 68 for electrical connection with the substrate 54 is formed in a region outside the effective pixel area 61 on the imaging surface of the imaging element 53.

  The substrate 54 is a rigid substrate or an FPC (Flexible printed circuits) substrate fixed to one end of the image sensor 53. A wire bond pad 70 that is electrically connected to the wire bond pad 68 of the image sensor 53 is formed on the substrate 54 via the bond wire 69. Thereby, the image pick-up element 53 and the board | substrate 54 are electrically connected via the bond wire 69 grade | etc.,.

  On the substrate 54, the peripheral circuit 71 is fixed or electrically connected. The peripheral circuit 71 controls driving of the image sensor 53. The peripheral circuit 71 is electrically connected to a cable distal end 31 a that is the distal end of the cable 31. Thereby, the imaging signal output from the imaging element 53 is output to the cable 31 via the peripheral circuit 71. When the image pickup device 53 is a CCD type, the image pickup signal output from the image pickup device 53 is converted into an image pickup signal or buffered by the peripheral circuit 71 and then output to the cable 31.

  6A is a cross-sectional view of the main parts (the prism 51, the cover glass 52, and the image sensor 53) of the imaging device 45 according to the first embodiment of the present invention, and FIG. 6B is a diagram of FIG. FIG. 6C is a cross-sectional view taken along line A2-A2 of FIG. 6A. In FIG. 6 and subsequent figures, the illustration of the spacer 60, the wire bond pad 68, the bond wire 69, and the like is omitted as appropriate in order to prevent the drawing from becoming complicated.

  As shown in FIGS. 6A to 6C, the prism 51 and the cover glass 52 adjacent to each other are bonded by a transparent adhesive layer 80 (not shown in FIG. 6B). At this time, in the space 83 between the prism 51 and the cover glass 52, four columnar spacers 85 that make the interval between the prism 51 and the cover glass 52 uniform are provided. The shape of the spacer 85 is not limited to a cylindrical shape, and may take various shapes such as a columnar shape such as a quadrangular prism shape and a spherical shape.

  Here, since the four corner portions (also referred to as diagonal portions) of the image area 64 on the image pickup surface of the image pickup device 53 have a substantially R shape, the difference area 67 (indicated by the shaded line in FIG. 6C). ) Of the four corners is larger than the area of other regions other than the four corners. For this reason, when the four corner portions of the difference area 67 are defined as the specific area 90, the specific area 90 has a larger area than the area other than the specific area in the difference area 67. The specific area 90 is not limited to the four corners in the difference area 67, and may be any area that has a relatively larger area in the difference area than other areas other than the specific area. This is a region that changes according to the shape.

  The spacers 85 are provided independently for each of the four corresponding regions 95 in the space 83 corresponding to each specific region 90. As a result, the spacer 85 projects the effective pixel area 61 of the rectangular (including substantially rectangular) imaging element 53 in the space 83 through which the subject light received by the effective pixel area 61 passes. It has a structure with four sides open. Note that the light transmission region 84 in this embodiment is a region having the same shape as the effective pixel area 61 represented by a dotted line in FIG.

  As the spacer 85 having such a structure, for example, a spacer 85 previously formed as the spacer 85 may be arranged for each corresponding region 95, or the emitting surface of the prism 51 is formed by plating (Cr or the like) or vapor deposition. May be. Since the corresponding area 95 is located on the specific area 90 that is not used for image display, even if the spacer 85 exists in the corresponding area 95, the image display is not affected. Since the specific area 90 corresponding to the four corners of the difference area 67 has a larger area than the other areas, it is possible to easily arrange and form the spacers 85 in the corresponding area 95.

[Effect of the present invention]
FIG. 7 is an explanatory diagram for explaining the effect of the imaging device 45. As shown in FIG. 7, the spacer 85 is provided for each corresponding region 95 corresponding to each specific region 90 having a large area in the difference area 67 so that the spacer 85 opens four sides of the light transmission region 84. Have. As a result, when the adhesive layer 80 is formed with an adhesive (indicated by dots in the figure) made of a transparent ultraviolet curable resin or a thermosetting resin, the light transmission region 84 is opened as indicated by the arrows in the figure. The bubbles contained in the adhesive and the excess adhesive can be discharged from the four sides. Rather than forming a groove in the light-shielding film as described in Patent Document 6 above, at least one side of the light transmission region 84 is open, so that the ability to discharge bubbles and excess adhesive is sufficiently enhanced. Can do.

  In addition, it is not necessary to manufacture the imaging device 45 by performing special processing on the prism as described in Patent Document 4 or using the W-CSP method as described in Patent Document 5. Since only the spacer 85 is required, the imaging device 45 can be manufactured at low cost.

  Further, when the prism 51 and the cover glass 52 are bonded with the adhesive layer 80, the spacers 85 are provided in the four corresponding regions 95 in the space 83, so that even when the parallelism does not appear in this bonding, the prism 85 is provided. Parallelism can be ensured with high accuracy by simply pressing 51 to the cover glass 52 at an angle free. As a result, the thickness of the adhesive layer 80 is made uniform, and the mounting accuracy of the prism 51 and the cover glass 52 in the imaging device 45 can be increased. In addition, from the viewpoint of ensuring parallelism, the spacers 85 are provided independently in corresponding areas corresponding to three or more specific areas, respectively.

  As described above, the imaging device 45 according to the first embodiment of the present invention includes the spacer 85 configured as described above, thereby improving the mounting accuracy of optical members such as the prism 51 and the cover glass 52 and being included in the adhesive. It is possible to discharge bubbles and excess adhesive at a low cost.

[Imaging Device of Second Embodiment]
Next, an imaging device 45A according to the second embodiment of the present invention will be described with reference to FIGS. 8A to 8C. 8A is a cross-sectional view of the main parts (the prism 51, the cover glass 52A, and the image sensor 53A) of the image pickup apparatus 45A, and FIG. 8B is a cross-sectional view taken along the line A1-A1 of FIG. FIG. 8C is a cross-sectional view taken along the line A2-A2 of FIG.

  In the imaging device 45 of the first embodiment, the effective pixel area 61 is formed at the center of the imaging surface of the imaging element 53, but the center of the effective pixel area 61A of the imaging device 45A is shifted from the center of the imaging surface. It is formed in the position. The imaging device 45A has basically the same configuration as the imaging device 45 of the first embodiment except that the imaging device 45A has a cover glass 52A, an imaging element 53A, and a spacer 85A that are different from the first embodiment. Therefore, the same reference numerals are given to the same functions and configurations as those in the first embodiment, and the description thereof is omitted.

  The cover glass 52A and the image sensor 53A are formed in a rectangular shape that extends long in a direction parallel to the optical axis OA. A rectangular effective pixel area 61A is formed on the imaging surface of the imaging element 53A. The effective pixel area 61A is formed on the end E1 on the lens barrel 50a side of the imaging surface.

  An image area 64A having basically the same shape as the image area 64 of the first embodiment is formed in the effective pixel area 61A and in the imaging area 63 (see FIG. 5). The image area 64A is formed at a position whose center is shifted from the center of the effective pixel area 61A toward the lens barrel 50a.

  The difference area 67A is an area inside the effective pixel area 61A and outside the image area 64A. In the difference area 67A, the area corresponding to the corner on the lens barrel 50a side and the area corresponding to the end opposite to the lens barrel 50a are specific areas where the area is wider than other areas. 90A.

  The prism 51 is bonded to the end E2 of the cover glass 52A on the lens barrel 50a side with an adhesive layer 80. The subject light incident surface 51a of the prism 51 is located further on the lens barrel 50a side than the end E2 of the cover glass 52A.

  The spacer 85A is provided independently for each of the three corresponding regions 95A in the space 83A between the prism 51 and the cover glass 52A and in the space 83A corresponding to each specific region 90A. As a result, the spacer 85A has a structure in which the four sides of the light transmission region 84A in which the effective pixel area 61A of the rectangular imaging element 53A is projected in the space 83A through which the subject light received by the effective pixel area 61A passes are opened. Have. Thereby, also in the imaging device 45A of the second embodiment, the same effects as those described in the first embodiment can be obtained.

  Here, the spacer 85A has a structure in which the four sides of the light transmission region 84A are opened. However, the spacer 85A may have a structure in which at least one side of the light transmission region 84A on the lens barrel 50a side is opened. The reason for opening this one side is that the position of the prism 51 is adjusted when the prism 51 is bonded onto the cover glass 52A. Therefore, if the spacer 85A is provided near the edge of the end portion E2, the prism 51 This is because the spacer 85A may fall from the cover glass 52A when the position is adjusted.

  FIGS. 9A and 9B are explanatory diagrams for explaining the unique effects of the imaging device 45A of the second embodiment. When the effective pixel area 61 is located at the center of the imaging surface as in the comparative imaging device 45P shown in FIG. 9A, the lens barrel 50a needs to be disposed on the cover glass 52A. As a result, in order to avoid the interference between the lens barrel 50a and the cover glass 52 and to ensure the clearance between them, the prism 51P is enlarged more than necessary, and the imaging device 45P is also enlarged.

  In contrast to such a comparative example, in the imaging device 45A of the present invention, the effective pixel area 61A is formed on the end E1 of the imaging surface, and the incident surface 51a of the prism 51 is a lens mirror than the end E2 of the cover glass 52A. The prism 51 is bonded onto the end E2 of the cover glass 52A so as to be positioned on the cylinder 50a side. Thereby, the mounting position of the lens barrel 50a can be shifted to the image sensor 53A side by Δh compared to the comparative example, so that the prism 51 can be made smaller than the comparative example. As a result, the imaging device 45A can be made smaller than before.

[Imaging Device of Third Embodiment]
Next, an image pickup apparatus 45B according to a third embodiment of the present invention will be described with reference to FIGS. 10A is a cross-sectional view of a main part of the imaging device 45B, and FIG. 10B is a cross-sectional view taken along line A1-A1 of FIG. 10A.

  In the first embodiment, the spacer 85 has a structure in which the four sides of the light transmission region 84 are opened. However, the imaging device 45B has a spacer 85B having a structure different from that of the first and second embodiments (FIG. 10 ( B) is indicated by a shaded line. Since the imaging device 45B has basically the same configuration as the imaging device 45 of the first embodiment except for the spacer 85B, the same reference numerals are used for the same functions and configurations as the first embodiment. The description is omitted.

  Two spacers 85B are formed on the emission surface, which is the surface facing the cover glass 52 of the prism 51, by plating (Cr or the like) or vapor deposition so as to sandwich the light transmission region 84 in the space 83. Specifically, the spacer 85B is formed on each of two sides orthogonal to the optical axis OA in the outer periphery of the emission surface (hereinafter simply referred to as the outer periphery of the emission surface), and has a shape extending long along these two sides. have. Thus, the spacer 85B has a structure in which two opposite sides of the light transmission region 84 are opened and the other two sides are closed.

  Since the spacer 85B has a structure in which two sides of the light transmission region 84 are open, when the adhesive layer 80 is formed, the bubbles or excess adhesive contained in the adhesive from the two open sides of the light transmission region 84 are formed. The agent can be discharged. Since the imaging device 45B has basically the same configuration as the imaging device 45 of the first embodiment except that the structure of the spacer 85B is different, the same effects as those described in the first embodiment can be obtained. It is done.

  FIG. 11 is an explanatory diagram for describing a modification of the imaging device 45B of the third embodiment. In the imaging device 45B of the third embodiment, the spacers 85B are formed on the two sides perpendicular to the optical axis OA in the outer periphery of the exit surface of the prism 51. However, as shown in FIG. Among them, the spacer 85B1 may be formed on two sides parallel to the optical axis OA. Since the configuration other than the spacer 85B1 is basically the same as that of the imaging device 45B of the third embodiment, a detailed description thereof will be omitted.

  The spacer 85B1 has basically the same structure as the spacer 85B except that the formation position is different from that of the spacer 85B of the third embodiment. For this reason, the effect similar to the effect of 3rd Embodiment is acquired.

[Imaging Device of Fourth Embodiment]
Next, an imaging device 45C according to the fourth embodiment of the present invention will be described with reference to FIGS. 12A is a cross-sectional view of a main part of the imaging device 45C, and FIG. 12B is a cross-sectional view taken along line A1-A1 of FIG.

  The imaging device 45C corresponds to a modified example of the imaging device 45A of the second embodiment shown in FIG. 8, and the second embodiment except that a spacer 85C is provided instead of the spacer 85A of the second embodiment. The configuration is basically the same as that of the imaging device 45A of the embodiment. For this reason, the same reference numerals are given to the same functions and configurations as those of the second embodiment, and the description thereof is omitted.

  Three spacers 85C are formed around the light transmission region 84A in the space 83A by plating (Cr or the like) or vapor deposition on the emission surface of the prism 51. Specifically, the spacer 85B is formed on each of the other three sides except for one side on the lens barrel 50a side in the outer periphery of the emission surface of the prism 51, and each has a shape that extends long. Yes. Thereby, the spacer 85C has a structure in which one side of the light transmission region 84 on the lens barrel 50a side is opened and the other three sides are closed.

  Thus, since the spacer 85C has a structure in which one side of the light transmission region 84 is opened, when forming the adhesive layer 80, bubbles or excess contained in the adhesive from one side where the light transmission region 84 is opened. Minute adhesive can be discharged.

  In the imaging device 45C, the spacer 85C has a structure that opens one side of the light transmission region 84A on the lens barrel 50a side, that is, the spacer 85C is formed at a position near the edge of the end E2. Not. Thereby, when the position adjustment at the time of adhesion | attachment of the prism 51 is performed, it is prevented that the spacer 85C falls from the cover glass 52A. Note that the imaging device 45C of the fourth embodiment has basically the same configuration as the imaging device 45A of the second embodiment except that the structure of the spacer 85C is different, and thus the imaging device described in the second embodiment. The same effect as that of 45A can be obtained.

[Image pickup apparatus of fifth embodiment]
Next, an imaging device 45D according to a fifth embodiment of the present invention will be described with reference to FIGS. 13A, 13B, and 14. FIG. 13A is a cross-sectional view of a main part of the imaging device 45D, and FIG. 13B is a cross-sectional view taken along line A1-A1 of FIG. FIG. 14 is an enlarged view of a portion surrounded by a dotted circle Q in FIG.

  In the imaging device 45B of the third embodiment shown in FIG. 10 above, the spacer 85B is formed on the edge of the outer periphery of the exit surface of the prism 51. For this reason, there is a possibility that the thickness of the space 83 and the adhesive layer 80 in the vicinity of the spacer 85B becomes non-uniform because the adhesive layer 80 contacts only one side of the spacer 85B. Therefore, the imaging device 45D is provided with a spacer 85D different from the spacer 85 of the third embodiment.

  Since the imaging device 45D has basically the same configuration as the imaging device 45B of the third embodiment except for the spacer 85D, the same reference numerals are used for the same functions and configurations as the third embodiment. The description is omitted.

  Similarly to the spacer 85B of the third embodiment, two spacers 85D are formed on the emission surface of the prism 51 by plating (Cr or the like) or vapor deposition so as to sandwich the light transmission region 84 in the space 83. Yes. However, the spacer 85D is formed at a position inside the two sides perpendicular to the optical axis OA on the outer periphery of the emission surface of the prism 51, and has a shape extending long along these two sides. Since the spacer 85D has a structure in which the two opposite sides of the light transmission region 84 are opened and the other two sides are closed, when the adhesive layer 80 is formed, the spacer 85D is separated from the two sides where the light transmission region 84 is opened. Air bubbles and excess adhesive contained in the adhesive can be discharged.

  In addition, by forming the spacer 85D at a position inside the two sides of the outer periphery of the emission surface of the prism 51, the adhesive layer 80 can be formed inside the outer periphery of each of the prism 51 and the cover glass 52, more specifically, each outer periphery. And the spacer 85D. As a result, since the adhesive layer 80 is provided on both sides of the spacer 85D, the thickness of the space 83 and the adhesive layer 80 in the vicinity of the spacer 85D can be made uniform.

  Note that the imaging device 45D of the fifth embodiment has basically the same configuration as the imaging device 45B of the third embodiment except that the structure of the spacer 85D is different. Therefore, the effects described in the third embodiment are the same. Similar effects can be obtained.

  FIG. 15 is an explanatory diagram for describing a modification of the imaging device 45D of the fifth embodiment. In the imaging device 45D of the fifth embodiment, the spacer 85D is formed on the inner side of two sides orthogonal to the optical axis OA in the outer periphery of the emission surface of the prism 51. As shown in FIG. The spacer 85D1 may be formed on the inner side of the outer periphery of two sides parallel to the optical axis OA.

  The spacer 85D1 has basically the same structure as the spacer 85D, except that the formation position is different from the spacer 85D of the fifth embodiment. For this reason, the effect similar to the effect demonstrated in 5th Embodiment is acquired.

[Image pickup apparatus of sixth embodiment]
Next, an imaging device 45E according to the sixth embodiment of the present invention will be described with reference to FIG. FIG. 16 is a cross-sectional view of the imaging device 45E. In the imaging device 45 of the first embodiment, the imaging element 53 is arranged so that its imaging surface is parallel to the optical axis OA of the observation optical system 50, and the subject light from the observation optical system 50 is transmitted by the prism 51. A so-called horizontal structure is adopted that is bent by 90 ° and incident on the imaging surface. On the other hand, the imaging device 45E employs a so-called vertical structure in which the imaging element 53 is arranged so that the imaging surface thereof is perpendicular to the optical axis OA of the observation optical system 50. Note that the same functions and configurations as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The imaging device 45E is roughly divided into an observation optical system 50 and a lens barrel 50a, a filter 98, a cover glass 52, an imaging element 53, a substrate 54E, a first peripheral circuit 100, and a second peripheral circuit 101. It is equipped with.

  The filter 98 corresponds to an optical member of the present invention, more specifically, one mode of the second optical member of the present invention. For example, an infrared cut filter or a laser cut filter is used. One surface of the filter 98 is bonded and fixed to the lens barrel 50 a, and the other surface is bonded and fixed to the cover glass 52. Thereby, the subject light is imaged on the imaging surface of the imaging element 53 through the observation optical system 50, the filter 98 and the cover glass 52.

  The substrate 54E is fixed to the surface opposite to the imaging surface of the image sensor 53. On the substrate 54E, connection portions such as bumps or lands that are electrically connected to through wiring portions (not shown) provided in the image sensor 53 are formed. Thereby, the image pick-up element 53 and the board | substrate 54E are electrically connected through a penetration wiring part and a connection part.

  The first peripheral circuit 100 and the second peripheral circuit 101 are fixed to the surface of the substrate 54E opposite to the surface on which the imaging element 53 is fixed. The first peripheral circuit 100 controls driving of the image sensor 53. The second peripheral circuit 101 is fixed in a state in which it is electrically connected to the surface opposite to the surface facing the substrate 54E of the first peripheral circuit 100. The second peripheral circuit 101 is connected to the cable 31 via the cable connection unit 104. As a result, the image signal output from the image sensor 53 is output to the cable 31 via the first and second peripheral circuits 100 and 101 and the like. The functions of the first peripheral circuit 100 and the second peripheral circuit 101 are not particularly limited.

  In the imaging device 45E according to the sixth embodiment, the filter 98 and the cover glass 52 are bonded to each other with the adhesive layer 80. In the space 83 </ b> E between the filter 98 and the cover glass 52, a spacer 85 that makes the distance between the prism 51 and the cover glass 52 uniform is provided. As in the first embodiment, the spacer 85 is a light transmission region that projects the effective pixel area 61 of the rectangular imaging element 53 in a space 83E through which subject light received by the effective pixel area 61 of the imaging element 53 passes. The four sides are open.

  As described above, the imaging device 45E according to the sixth embodiment is basically configured in the same manner as the imaging device 45 according to the first embodiment except that the filter 98 is bonded to the cover glass 52 instead of the prism 51 according to the first embodiment. Since these are the same, the same effects as those described in the first embodiment can be obtained.

  Instead of providing the spacer 85 in the space 83E, the spacer 85B of the third embodiment may be provided.

[Example of application of imaging device to capsule system]
Examples of the electronic endoscope on which the imaging apparatus having the above configuration is mounted include a flexible endoscope, a rigid endoscope, an industrial endoscope, a capsule system (also referred to as a capsule endoscope), and the like. Hereinafter, a capsule system will be described as an example and will be described in detail with reference to the drawings.

  As shown in FIG. 17, the capsule system 501 includes an illumination system 512 and a camera including an optical system 514 and an image sensor 516. The image captured by the image sensor 516 is processed by the image processor 518. The image processor 518 is implemented by software executed by a digital signal processor (DSP) or a central processing unit (CPU), by hardware, or by a combination of both software and hardware. be able to. The processed image is compressed by an image compression subsystem 519 (in some embodiments, implemented in software executed by the DSP of the image processor 518). The compressed data is stored in the archive memory system 520. The capsule system 501 includes a battery power source 521 and an output port 526. The capsule system 501 can advance through the digestive tract (GI tract) 500 by peristalsis.

  The illumination system 512 can also be configured with LEDs. In FIG. 17, the LEDs are arranged close to the camera opening, but other arrangements are possible. A light source may be provided, for example, behind the opening. Other light sources such as laser diodes may be used. Alternatively, a white light source or a combination of two or more narrow wavelength band light sources may be used. It is also possible to use a white LED with a phosphorescent material that is excited by the light of the LED to emit long wavelength light. The white LED may include a blue LED or a purple LED. The predetermined portion of the capsule housing for allowing light to pass is made from a biologically compatible glass or polymer.

  The optical system 514 allows the image sensor 516 to read an image of the wall of the lumen of the GI tube 500 or the like, and includes a plurality of refractive lens elements, diffractive lens elements, or reflective lens elements. good.

  The image sensor 516 converts the received light intensity into a corresponding electrical signal and can be provided by a charge coupled device (CCD) or complementary metal oxide semiconductor (CMOS) type device. The image sensor 516 may be monochromatic, or may include a color filter array that can capture a color image (eg, using RGB or CYM representations).

  The image sensor 516 corresponds to an embodiment of the imaging device of the present invention, and is configured to include basically the same one as the imaging device of each of the above embodiments. Also in this image sensor 516, since the spacer has a structure in which at least one side of the light transmission region is opened, the same effects as those described in the above embodiments can be obtained.

  The analog signal from the image sensor 516 is preferably converted to digital form so that it can be processed in digital form. Such a conversion is performed using an analog-to-digital (A / D) converter provided in the sensor (in this embodiment) or in another part of the capsule housing 510. An A / D unit can also be provided between the image sensor 516 and other parts of the system. The LEDs of the illumination system 512 are synchronized with the operation of the image sensor 516. One of the functions of the control module (not shown) of the capsule system 501 is to control the LED during an image capture operation.

  FIG. 18 illustrates a swallowable capsule system 502 according to one embodiment of the present invention. The capsule system 502 can be configured substantially similar to the capsule system 501 of FIG. 17 except that the archive memory system 520 and the output port 526 are not required. The capsule system 502 also includes a communication protocol encoder 1320 and a transmitter 1326 used for wireless transmission. Of the elements of the capsule system 501 and the capsule system 502, substantially the same elements are given the same reference numerals. Therefore, their structure and function will not be described again here. The control module 522 performs overall control of the entire capsule system 502. The communication protocol encoder 1320 is implemented by software executed by a DSP or CPU, hardware, or a combination of software and hardware. The transmitter 1326 includes an antenna system for transmitting the captured digital image.

[Others]
The spacers of the imaging devices of the above embodiments are not limited to those described in the above embodiments, and the shape, arrangement, size, and the like are as long as they have a structure in which at least one side of the light transmission region is open. You may change suitably. In particular, when the spacer is formed by plating or vapor deposition, the spacer can have any shape.

  In the imaging devices according to the third to fifth embodiments, the spacer is formed on the exit surface of the prism by plating or vapor deposition. However, the spacer may be formed on the surface of the cover glass facing the prism. . Further, instead of forming the spacer by plating or vapor deposition, a previously formed spacer may be disposed between the prism and the cover glass.

  In each of the above-described embodiments, the cover glass, the prism, and the filter have been described as examples of the plurality of optical members (first optical member, second optical member) of the present invention. The present invention can also be applied when various optical members are bonded together with an adhesive layer.

  In the first embodiment and the like, the substrate 54 is bonded and fixed to one end of the image sensor 53, and the image sensor 53 and the substrate 54 are electrically connected via a bond wire 69 or the like. As shown, the substrate 54Q may be fixed on the outer periphery of the imaging surface of the imaging element 53. In this case, bumps and lands (not shown) that are electrically connected to the connection portion 200 provided on the substrate 54Q are formed on the outer peripheral portion of the imaging surface. Thereby, the image pick-up element 53 and the board | substrate 54Q are electrically connected via the connection part 200 grade | etc.,. In addition, the code | symbol 202 in a figure is the frame-shaped reinforcement resin formed so that the outer periphery of the cover glass 52 might be enclosed on an imaging surface.

  In each of the above embodiments, the electronic endoscope having the imaging device of the present invention has been described. However, the imaging device of the present invention can be provided in various devices and systems such as a digital camera.

  It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Endoscope apparatus, 11 ... Electronic endoscope, 16 ... Insertion part, 16a ... Tip part of insertion part, 45 ... Imaging apparatus, 45A-45E ... Imaging apparatus, 50 ... Observation optical system, 51 ... Prism, 52 ... Cover glass 53... Image sensor 61. Effective pixel area 64. Image area 67. Difference area 80. Adhesive layer 84 Light transmission region 85 Spacer 85 A to 85 D Spacer 90 90 Specific region 95 ... corresponding area, 98 ... filter

Claims (14)

A plurality of optical members; and an imaging element having a rectangular effective pixel area that receives subject light through the plurality of optical members; and a first optical member adjacent to each other among the plurality of optical members; In the imaging device in which the second optical member is bonded with an adhesive layer,
In the space between the first optical member and the second optical member, the adhesive layer is at least in a region through which the subject light received by the effective pixel area of the rectangular imaging element passes. Formed,
A spacer that is provided in a space between the first optical member and the second optical member, and that makes the interval between the first optical member and the second optical member uniform, the effective pixel provided in the space in which the object light received by the area through a spacer having a structure which is open at least a portion of one side of the rectangular light transmitting region defined by projecting the effective pixel area of the imaging element,
The imaging device in which the part of the one side is formed wider than a part of the one side different from the part. When the area used for image display in the effective pixel area is an image area, and the area inside the effective pixel area and the outside of the image area is a difference area, the difference area includes a specific area. And a specific region having an area larger than the region other than the specific region in the difference area is included,
The imaging device according to claim 1, wherein the spacer is provided in a corresponding area corresponding to the specific area in the space. The difference area includes three or more specific areas,
The imaging device according to claim 2, wherein the spacer is provided independently for each corresponding region.   The imaging device according to claim 3, wherein the specific area is an area corresponding to four corners of the difference area. A plurality of optical members; and an imaging element having a rectangular effective pixel area that receives subject light through the plurality of optical members; and a first optical member adjacent to each other among the plurality of optical members; In the imaging device in which the second optical member is bonded with an adhesive layer,
In the space between the first optical member and the second optical member, the adhesive layer is at least in a region through which the subject light received by the effective pixel area of the rectangular imaging element passes. Formed,
A spacer that is provided in a space between the first optical member and the second optical member, and that makes the interval between the first optical member and the second optical member uniform, the effective pixel in the space in which the object light received by the area passes, imaging apparatus including a spacer having the structure fully open at least one side of the rectangular light transmitting region defined by projecting the effective pixel area of the imaging element.   The imaging device according to claim 5, wherein the spacer has a structure in which two sides of the light transmission region are completely opened.   The imaging device according to claim 6, wherein the spacer has a structure in which two opposite sides of the light transmission region are completely opened and the other two sides are closed.   The first optical member is a cover glass that covers an imaging surface on which the effective pixel area of the imaging element is formed, and the second optical member is a lens mirror having an optical axis parallel to the imaging surface. 5. The imaging device according to claim 1, wherein the imaging device is a prism that bends the subject light incident from the cylinder by 90 ° and causes the light to be incident on the cover glass. The effective pixel area is formed on an end of the imaging surface on the lens barrel side,
The prism is bonded to the end portion of the cover glass on the lens barrel side by the adhesive layer, and the incident surface on which the subject light is incident is more than the end portion of the cover glass on the lens barrel side. Located on the lens barrel side,
The imaging device according to claim 8, wherein the spacer has a structure that opens at least a part of one side of the light transmission region on the lens barrel side.   The first optical member is a cover glass that covers an imaging surface on which the effective pixel area of the imaging element is formed, and the second optical member is a lens mirror having an optical axis parallel to the imaging surface. The imaging apparatus according to claim 5, wherein the imaging apparatus is a prism that bends the subject light incident from the cylinder by 90 ° and causes the light to enter the cover glass. The effective pixel area is formed on an end of the imaging surface on the lens barrel side,
The prism is bonded to the end portion of the cover glass on the lens barrel side by the adhesive layer, and the incident surface on which the subject light is incident is more than the end portion of the cover glass on the lens barrel side. Located on the lens barrel side,
The imaging device according to claim 10, wherein the spacer has a structure that completely opens at least one side of the light transmission region on the lens barrel side.   The first optical member is a cover glass that covers an imaging surface on which the effective pixel area of the imaging element is formed, and the second optical member is a surface that faces the imaging element of the cover glass. The imaging apparatus according to claim 1, wherein is a filter provided on the opposite surface side. The spacer is provided inside the outer periphery of each of the first optical member and the second optical member in the space,
The imaging device according to claim 1, wherein the adhesive layer is provided inside the outer periphery including between the outer periphery and the spacer.   The imaging device according to any one of claims 1 to 13, wherein the spacer is formed by plating or vapor deposition on a surface of the second optical member that faces the first optical member.

Images