JP5877231B2 - Imaging module - Google Patents

Description

  The present invention relates to an imaging module having an imaging element and an optical member.

  2. Description of the Related Art Conventionally, various types of electronic imaging devices have appeared, such as digital cameras and digital video cameras, endoscope devices for observing the inside of a subject's organs, and mobile phones with an imaging function. Among these, the endoscope apparatus has a built-in imaging module in which an imaging element is mounted at the distal end portion of a flexible elongated insertion tool. By inserting this insertion tool into a body cavity, a region to be examined is obtained. Can be observed.

  This imaging module incorporates an image sensor such as a CCD or CMOS image sensor, forms an optical image of a subject in a light receiving area of the image sensor by an optical system such as a lens, and subjects the image by photoelectric conversion processing of the image sensor. Image data.

  Here, conventionally, in order to reduce the burden on the subject, the endoscope apparatus has been required to have a thin tip of the insertion tool. In recent years, the objective lens system has been designed so that a sufficient light-receiving area can be secured on the image sensor even when the area of the vertical plane with respect to the optical axis that can be used for the imaging module is reduced by reducing the diameter of the tip of the insertion tool. There has been proposed an imaging module in which a prism is placed on an imaging device arranged substantially parallel to the optical axis (see, for example, Patent Document 1).

JP-A-8-106055

  However, the conventional imaging module is manufactured by a complicated manufacturing process in which a cover glass is attached to a prism, the set is fitted into one end of the cover glass holder, and a lens cover is attached to the other end of the cover glass holder. It was.

  The present invention has been made in view of the above, and an object thereof is to provide an imaging module that can be easily manufactured.

  In order to solve the above-described problems and achieve the object, an imaging module according to the present invention includes a hollow lens holder having both ends opened, and light incident from one end of the lens holder, which is assembled inside the lens holder. A hollow imaging holder having an opening through which light emitted from the lens is incident, and an optical member that is assembled inside the imaging holder and transmits or refracts light incident from one end of the imaging holder And an image sensor on the surface of which a light receiving region that receives light transmitted or refracted by the optical member and photoelectrically converts the light transmitted or refracted by the optical member is formed, and the light emitting side of the lens holder By fitting the end portion and the imaging holder, the center of the optical axis of the lens and the center of the light received in the light receiving region of the imaging element coincide with each other. And butterflies.

  Further, the imaging module according to the present invention is characterized in that the position of the light emitting side end of the lens holder is defined by at least a part of the outer peripheral surface of the imaging holder.

  Further, the imaging module according to the present invention is characterized in that the position of the light emitting side end of the lens holder is defined by at least a part of the peripheral surface of the optical member.

  Further, the imaging module according to the present invention is characterized in that the position of the light emitting side end portion of the lens holder is defined by at least a part of the outer peripheral surface of the optical member.

  Further, the imaging module according to the present invention is characterized in that the position of the light emitting side end portion of the lens holder is defined by at least a part of the inner peripheral surface of the optical member.

  The imaging module according to the present invention is characterized in that marks that define the positions of the holders in the axial direction are respectively attached to the outer peripheral surface of the lens holder and the outer peripheral surface of the imaging holder.

  In the imaging module according to the present invention, the optical member has a light incident surface formed with a protrusion having a size matching the inner peripheral surface or the outer peripheral surface of the light emitting side end of the lens holder, The light emission side end of the holder has an optical axis center of the lens and a center of light received by the light receiving region of the imaging element by fitting an inner peripheral surface or an outer peripheral surface to a peripheral surface of the protrusion of the optical member. And the position in the axial direction is defined by applying the tip to the light incident surface of the optical member.

  Moreover, the imaging module according to the present invention is characterized in that the imaging module is mounted at a distal end portion of an endoscope apparatus inserted into a living body.

  In the imaging module according to the present invention, the center of the optical axis of the lens and the center of the light received in the light receiving region of the imaging device are matched by simply fitting the lens holder and the imaging holder fitted to the lens holder. An imaging module can be manufactured easily.

FIG. 1 is a diagram illustrating a schematic configuration of an endoscope apparatus according to the first embodiment. FIG. 2 is an exploded perspective view of the imaging module mounted on the distal end portion of the endoscope apparatus shown in FIG. FIG. 3 is a cross-sectional view of the imaging module shown in FIG. FIG. 4 is an exploded perspective view of the imaging module according to the second embodiment. FIG. 5 is a cross-sectional view of the imaging module shown in FIG. FIG. 6 is an exploded perspective view of the imaging module according to the third embodiment. FIG. 7 is a cross-sectional view of the imaging module shown in FIG. FIG. 8 is an exploded perspective view of an imaging module according to a modification of the third embodiment. FIG. 9 is a cross-sectional view of the imaging module shown in FIG. FIG. 10 is a cross-sectional view of another example of an imaging module according to a modification of the third embodiment. FIG. 11 is a cross-sectional view of another example of an imaging module according to a modification of the third embodiment. FIG. 12 is a cross-sectional view of another example of an imaging module according to a modification of the third embodiment. FIG. 13 is a cross-sectional view of another example of an imaging module according to a modification of the third embodiment.

  Hereinafter, an imaging module built in a distal end portion of an insertion tool of an endoscope apparatus will be described in detail as an example of an imaging module according to an embodiment of the present invention with reference to the accompanying drawings. Note that the present invention is not limited to these embodiments. In the description of the drawings, the same parts are denoted by the same reference numerals. The drawings are schematic, and it is necessary to note that the relationship between the thickness and width of each member, the ratio of each member, and the like are different from the actual ones. Also in the drawings, there are included portions having different dimensional relationships and ratios.

(Embodiment 1)
First, the endoscope apparatus according to the first embodiment will be described. FIG. 1 is a diagram illustrating a schematic configuration of the endoscope apparatus according to the first embodiment. As shown in FIG. 1, an endoscope apparatus 1 according to the first embodiment includes an elongated insertion part 2 and an operation part 3 on the proximal end side of the insertion part 2 and held by an endoscope apparatus operator. And a flexible universal cord 4 extending from the side portion of the operation portion 3. The universal cord 4 includes a light guide cable, an electric cable, and the like.

  The insertion portion 2 includes a distal end portion 5 incorporating an imaging module having an imaging element such as a CCD, a bending portion 6 that is configured by a plurality of bending pieces, and a length provided on the proximal end side of the bending portion 6. And a flexible tube portion 7 having flexibility.

  A connector portion 8 is provided at the end of the universal cord 4 on the extending side. The connector portion 8 has a light guide connector 9 that is detachably connected to the light source device, an electrical signal of a subject image photoelectrically converted by a CCD or the like. Are provided with an electric contact portion 10 for transmitting the air to the signal processing device and the control device, an air supply base 11 for sending air to the nozzle of the tip portion 5, and the like. The light source device includes a halogen lamp or the like, and supplies light from the halogen lamp as illumination light to the endoscope device 1 connected via the light guide connector 9. The signal processing device or the control device is a device that supplies power to the image sensor and receives an electrical signal photoelectrically converted from the image sensor, and displays a display that processes and connects the electrical signal captured by the image sensor An image is displayed on the apparatus, and a drive signal for controlling and driving gain adjustment of the image sensor is output.

  The operation unit 3 includes a bending knob 12 for bending the bending unit 6 in the vertical direction and the horizontal direction, a treatment tool insertion unit 13 for inserting a treatment tool such as a biopsy forceps and a laser probe into the body cavity, a signal processing device or a control device, A plurality of switches 14 for operating peripheral devices such as air supply, water supply, and gas supply means are provided. The endoscope apparatus 1 in which the treatment tool is inserted into the treatment tool insertion port projects the distal treatment portion of the treatment tool through the treatment tool insertion channel provided therein, and collects the affected tissue using, for example, biopsy forceps Perform biopsy.

  Next, the configuration of the imaging module mounted on the distal end portion 5 of the endoscope apparatus 1 will be described. 2 is an exploded perspective view of the imaging module mounted on the distal end portion 5 of the endoscope apparatus 1 shown in FIG. 1, and FIG. 3 is a cross-sectional view of the imaging module shown in FIG. It is sectional drawing at the time of cut | disconnecting in a surface perpendicular | vertical with respect to the light-receiving region surface of the image pick-up element to perform.

  As shown in FIGS. 2 and 3, the imaging module 15 mounted on the distal end portion 5 of the endoscope apparatus 1 shown in FIG. 1 includes an imaging unit having a lens unit 20 having a plurality of objective lenses and an imaging element 33. 30.

  The lens unit 20 includes a hollow cylindrical lens holder 21 formed of a light-shielding material and open at both ends, lenses 22 and 23 that collect light from the outside, and an observation window 24 that transmits light from the outside. Composed.

  The opening size of the lens holder 21 is a size that matches the outer periphery of the lenses 22 and 23 and the observation window 24. As shown in FIGS. 3 (1) and 3 (2), the lenses 22 and 23 and the observation window 24 are provided. Are assembled in the lens holder 21 so that their centers are located on the same axis. At the time of assembling each optical member of the lens holder 21, the light of the lens unit 20 constituted by the outer diameter central axis of the lens holder 21 and the centers of the lenses 22, 23 and the observation window 24, that is, the lenses 22, 23 and the observation window 24. The shape of each optical member and the lens holder 21 is designed so as to coincide with the axis center. The lens holder 21 is made of, for example, corrosion resistant steel, and at least the outer side is shielded from light.

  Light from the outside incident on the inside of the lens holder 21 through the observation window 24 from the opening 21 a at the end of the lens holder 21 is collected by the lenses 22 and 23. The condensed light collected by the lenses 22 and 23 is emitted from the opening 21 b at the other end of the lens holder 21. The thickness of the exit end on the opening 21b side of the lens holder 21 is substantially uniform in the circumferential direction.

  The imaging unit 30 includes a hollow cylindrical imaging holder 31 having both ends opened, an imaging element 33 mounted on a substrate 32, and a prism 34 placed on the imaging element 33. The imaging holder 31 is made of, for example, corrosion resistant steel.

  The imaging element 33 is a bare chip-shaped semiconductor element exemplified by a CCD or CMOS image sensor, and has an imaging function of receiving light from a subject and capturing an image of the subject. As shown in FIG. 3, the image sensor 33 has a light receiving region 33a on the upper surface of the chip substrate for receiving light from the subject and performing photoelectric conversion processing on the received light. When the imaging module 15 is completed, the imaging element 33 is arranged so that the optical axis of the lens unit 20 and the surface of the light receiving region 33a are substantially parallel.

  The light receiving region 33a is realized by using a pixel group arranged in a predetermined shape such as a lattice shape, a microlens formed on the pixel group in order to efficiently collect light. The surface of the light receiving region 33 a is rectangular, and the light receiving region 33 a is formed at a predetermined position on the chip substrate of the image sensor 33. The image sensor 33 includes a drive circuit unit (not shown) in which a drive circuit for executing an imaging operation is formed, and an external connection electrode (not shown).

  The imaging element 33 is mounted on the substrate 32 by connecting the external connection electrode and the external connection electrode of the substrate 32 with a wire 35. At this time, the image sensor 33 is mounted on the substrate 32 with the surface on which the light receiving region 33a is formed as an upper surface. The light receiving region 33a performs photoelectric conversion processing on the received light, and the drive circuit unit generates an image signal of the subject based on the signal subjected to photoelectric conversion processing in the light receiving region 33a, and the generated image signal is connected to the external connection. And output to the substrate 32 through the electrode for use. The image signal output to the substrate 32 is transmitted to the signal processing device and the control device by the wiring cable 37 connected to the substrate 32. Note that a signal control component 36 may be mounted on the substrate 32.

  The prism 34 is placed on the light receiving region 33a of the image sensor 33 and refracts light from the outside. The light refracted by the prism 34 is received by the light receiving region 33 a of the image sensor 33. A concave portion (not shown) for forming an air gap is formed on the bottom surface of the prism 34 immediately above the microlens in the light receiving region 33a. The prism 34 has a prismatic shape in which the light incident surface 34a is a trapezoid. Then, as shown in FIG. 3B, in the prism 34, the light passing through the position indicated by the point C2 on the light incident surface 34a of the prism 34 is refracted by the refractive surface of the prism 34, and then the light receiving region 33a of the image sensor 33. It is mounted on the image sensor 33 so as to reach the center C1. This point C2 corresponds to the center of the reference area that is the area where the light received by the light receiving area 33a is incident on the light incident surface 34a of the prism 34.

  The imaging holder 31 has a hollow shape obtained by hollowing out a prism having a trapezoidal bottom surface from a cylinder. The sizes of the openings 31a and 31b are set so that the openings 32a and 31b can be assembled into the image pickup holder 31 from the openings 31b in a state where the substrate 32, the image pickup device 33, and the prism 34 are mounted. For example, the size of the openings 31a and 31b in the height direction substantially matches the sum of the substrate thickness of the substrate 32, the substrate thickness of the image sensor 33, and the light incident surface height of the prism 34. The size in the width direction of 31 b is larger than the size in the short side direction of the substrate 32. The substrate 32, the imaging element 33, and the prism 34 are assembled in the imaging holder 31 in a mounted state.

  At this time, a part of the outer peripheral surface of the light incident surface 34 a of the prism 34 is fixed to the inner peripheral surface of the imaging holder 31, whereby the substrate 32, the imaging element 33, and the prism 34 are assembled inside the imaging holder 31. Note that when assembling each optical member of the imaging holder 31, each optical member and the imaging are arranged such that the point C <b> 2 that is the center of the reference region of the light incident surface 34 a of the prism 34 is positioned on the outer diameter central axis of the imaging holder 31. The shape of the holder 31 may be designed.

  Here, the inner diameter of the light emitting side end of the lens holder 21 and the outer diameter of the light incident side end of the imaging holder 31 are set to coincide with each other. That is, the inner diameter R21b of the opening 21b of the lens holder 21 and the outer diameter R31a of the opening 31a of the imaging holder 31 are the same diameter.

  For this reason, the light incident side end of the imaging holder 31 is inserted into the lens holder 21 through the opening 21b of the lens holder 21 as indicated by the arrow in FIG. The exit side end and the light incident side end of the imaging holder 31 can be directly fitted as shown in FIG.

  As described above, the outer diameter central axis of the lens holder 21 and the optical axis center of the lens unit 20 coincide with each other, and the center of the reference region of the light incident surface 34a of the prism 34 on the outer diameter central axis of the imaging holder 31 is obtained. When the imaging holder 31 is inserted into the lens holder 21, the center of the optical axis of the lens unit 20 passing through the center C3 of the lens 22 and the reference region of the light incident surface 34a of the prism 34 are located. The center point C2 is located on the same axis L1.

  As described above, the lens holder 21 and the imaging holder 31 are based on the size of each constituent member of the lens unit 20, the size of each constituent member of the imaging holder 31, the optical axis of each optical system, and the like. The optical axis center of the lenses 22 and 23 assembled to the lens holder 21 is fixed to the inside of the imaging holder 31 when the light emission side end of the lens holder 21 and the light incident side end of the imaging holder 31 are fitted. The shape is designed to pass through the point C2, which is the center of the reference region. Further, since a part of the outer peripheral surface of the light incident surface of the prism 34 is fixed to the inner peripheral surface of the imaging holder 31, the inner peripheral surface 21 c of the light emitting side end portion of the lens holder 21 is the optical axis of the lens unit 20. The position is defined by the outer peripheral surface 31c of the imaging holder 31 so that the center and the point C2 that is the center of the reference region of the light incident surface 34a of the prism 34 are located on the same axis L1.

  The prism 34 is mounted on the image sensor so that the light passing through the point C2, which is the center of the reference area of the light incident surface 34a of the prism 34, reaches the center C1 of the light receiving area 33a. For this reason, the condensed light from the lenses 22 and 23 of the lens holder 21 is incident on the light incident surface 34 a of the prism 34 in a state where the center of the optical axis coincides with the center of the light receiving region 33 a of the image sensor 33. Accordingly, when the light emitting side end of the lens holder 21 and the light incident side end of the imaging holder 31 are fitted, the optical axis center of the optical member including the lenses 22 and 23 of the lens unit 20 and the imaging unit 30 The center of the light received by the light receiving region 33a of the image sensor 33 coincides.

  Further, as shown in FIG. 2, a triangular mark M <b> 2 is attached to the collected light emitting side end portion of the outer peripheral surface of the lens holder 21, and the light incident side end of the outer peripheral surface 31 c of the imaging holder 31. A triangle mark M3 is attached to the part. The marks M2 and M3 are attached so that the positions of the holders in the direction of the axis L1 and the circumferential direction of each holder (the circumferential direction around the axis L1) can be defined.

  At the time of assembly, first, an adhesive is applied to at least one of the inner peripheral surface 21c of the exit side end portion of the lens holder 21 or the outer peripheral surface 31c of the incident side end portion of the imaging holder 31. Next, the imaging holder 31 is fitted into the lens holder 21 so that the vertex of the mark M2 of the lens holder 21 and the vertex of the mark M3 of the imaging holder 31 are coaxial with each other when viewed from above. Then, the imaging holder 31 is inserted into the lens holder 21 until the vertex of the mark M3 of the imaging holder 31 reaches the vertex of the mark M2 of the lens holder 21. Depending on the type of adhesive, an adhesive curing process is further performed.

  As described above, in the imaging module 15 according to the first embodiment, the optical axis center of each optical member that passes through the center C3 of the lens 22 and the point C2 that is the center of the light incident surface 34a of the prism 34 coincide with each other. The end of the condensed light exit side of the lens holder 21 is defined by the outer peripheral surface of the imaging holder 31. In other words, the imaging module 15 condenses the lens holder 21 so that the optical axis center of each optical member passing through the center C3 of the lens 22 and the center of the light received by the light receiving region 33a of the imaging element 33 coincide. The position of the light emitting side end is defined by the outer peripheral surface of the imaging holder 31. For this reason, the optical axis center of the optical member of the lens unit 20 and the imaging can be obtained by a simple manufacturing process in which the collected light emitting side end of the lens holder 21 and the collected light incident side end of the imaging holder 31 are simply fitted together. An imaging module in which the center of the light received by the light receiving region 33a of the imaging element 33 of the unit 30 is matched can be manufactured.

  In the imaging module 15, the condensing light emitting side end of the lens holder 21 and the imaging holder 31 are aligned so that the mark M 2 attached to the outer periphery of the lens holder 21 and the mark M 3 attached to the outer periphery of the imaging holder 31 are aligned. By simply fitting the collected light incident side end portion, the position in the direction of the axis L1 of each holder and the position in the circumferential direction around the axis L1 of each holder can be accurately defined.

  In addition, the imaging module 15 can directly fit the collected light emitting side end of the lens holder 21 and the collected light incident side end of the imaging holder 31 without using any other member. The diameter of the distal end portion of the insertion tool of the apparatus can be reduced, and the loss of light quantity due to the intervention of the members can be reduced, so that a good image can be acquired.

(Embodiment 2)
Next, a second embodiment will be described. In the second embodiment, an imaging module assembled by inserting a lens holder into an imaging holder will be described.

  FIG. 4 is an exploded perspective view of the imaging module according to the second embodiment, and FIG. 5 is a cross-sectional view of the imaging module shown in FIG. 4, and is perpendicular to the surface of the light receiving region of the imaging device that constitutes the imaging module. It is sectional drawing at the time of cut | disconnecting in a smooth surface. As shown in FIGS. 4 and 5, the imaging module 215 according to the second embodiment includes a lens unit 220 and an imaging unit 230 having an imaging element 33.

  The lens unit 220 includes a hollow cylindrical lens holder 221 that is open at both ends, lenses 222 and 223 that collect light from the outside, and an observation window 224 that transmits light from the outside.

  The opening 221a of the lens holder 221 has a circular shape that matches the outer circumference of the lenses 222, 223 and the observation window 224. As shown in FIGS. 5 (1) and 5 (2), the lenses 222, 223 and The observation window 224 is assembled inside the lens holder 221 so that the center of each of the observation windows 224 is positioned coaxially with the outer diameter central axis of the lens holder 221. Light from the outside that enters the lens holder 221 through the observation window 224 from the opening 221a at the end of the lens holder 221 is collected by the lenses 222 and 223, and this condensed light is collected at the other end of the lens holder 221. The light is emitted from the opening 221b. Of the opening 221 b of the lens holder 221, at least a portion (end portion 231 j shown in FIG. 5A) that contacts the outer peripheral surface of the prism 34 has a trapezoidal opening shape that is the same shape as the light incident surface 34 a of the prism 34. ing. The lens holder 221 is made of, for example, corrosion resistant steel, and at least the outer side is shielded from light.

  The imaging unit 230 includes a hollow imaging holder 231 having both ends opened, an imaging element 33 mounted on the substrate 32, and a prism 34 placed on the imaging element 33. The imaging holder 231 is made of, for example, corrosion resistant steel.

  The imaging holder 231 has a shape in which a cylinder protrudes from one side of a prism. The columnar portion of the imaging holder 231 has a substantially hollow cylindrical shape, and the prism portion has a hollow shape obtained by hollowing out a prism having a trapezoidal bottom surface.

  The size of the opening 231b in the prismatic part of the imaging holder 231 is set so that it can be assembled into the imaging holder 231 via the opening 231b in a state where the substrate 32, the imaging device 33, and the prism 34 are mounted. Is done. The substrate 32, the imaging element 33, and the prism 34 are assembled inside the imaging holder 231 by fixing a part of the bottom surface of the substrate 32 to the inner peripheral surface of the imaging holder 231. For example, when the optical members of the imaging holder 231 are assembled, the optical members and the imaging are arranged so that the point C2 that is the center of the reference region of the light incident surface 34a of the prism 34 is positioned on the outer diameter central axis of the imaging holder 231. The shape of the holder 231 is designed. As in the first embodiment, as shown in FIG. 5B, in the prism 34, the light passing through the point C2 on the light incident surface 34a of the prism 34 is the center C1 of the light receiving region 33a of the image sensor 33. It is mounted on the image sensor 33 so as to reach.

  The inner diameter of the circular opening 231 a of the cylindrical portion of the imaging holder 231 to which the condensed light emitted from the lens unit 220 is incident is larger than the outer diameter of the lens holder 221. For this reason, as shown by the arrow in FIG. 5A, the light emitting side end of the lens holder 221 is fitted into the imaging holder 231 through the opening 231 b of the cylindrical portion of the imaging holder 231. The light emission side end of 221 and the light incidence side end of the imaging holder 231 can be directly fitted as shown in FIG.

  Here, when the lens holder 221 and the imaging holder 231 are fitted to the light emitting side end of the lens holder 221 and the light incident side end of the imaging holder 231, the optical axis of the lens unit 220 passing through the center C32 of the lens 222. The shape is designed so that the center passes through the point C2 of the light incident surface 34a of the prism 34 fixed inside the imaging holder 231. Further, the opening shape of the end portion 231j of the opening 221b of the lens holder 221 and the shape of the light incident surface 34a of the prism 34 assembled to the imaging holder 231 are formed to be the same shape. By directly fitting the inner peripheral surface 221c to the outer peripheral surface 34c of the prism 34, the position of the lens holder 221 in the vertical direction in the drawing of FIG. That is, when the light emitting side end of the lens holder 221 and the light incident side end of the imaging holder 231 are fitted, the center of the optical axis of the lens unit 220 passing through the center C32 of the lens 222 and the light incident surface 34a of the prism 34. The inner peripheral surface 221c of the light emitting side end portion of the lens holder 221 is directly positioned by the outer peripheral surface 34c of the prism 34 so that the point C2 is located on the same axis L2. Since the prism 34 is mounted on the image sensor 33 so that the light passing through the point C2 of the light incident surface 34a reaches the center C1 of the light receiving region 33a, the optical axis center of the optical member of the lens unit 220 and the imaging The center of the light received by the light receiving region 33a of the image sensor 33 of the unit 230 coincides with the center. Note that a part of the outer peripheral surface of the light emitting side end of the lens holder 221 is also defined by a part of the inner peripheral surface of the imaging holder 231.

  As in the first embodiment, as shown in FIG. 4, the condensed light exit side end outer peripheral surface of the lens holder 221 and the light incident side end outer peripheral surface of the imaging holder 231 are arranged in the direction of the axis L2 and each A triangular mark M22 and a triangular mark M32 for defining the position of each holder in the circumferential direction of the holder (circumferential direction about the axis L2) are respectively attached.

  At the time of assembly, first, an adhesive is applied to the inner peripheral surface 221c of the emission side end of the lens holder 221. Next, the lens holder 221 is fitted into the imaging holder 231 so that the vertex of the mark M22 of the lens holder 221 and the vertex of the mark M32 of the imaging holder 231 are coaxial when viewed from above. Then, the imaging holder 231 is inserted into the lens holder 221 until the vertex of the mark M22 of the lens holder 221 reaches the vertex of the mark M32 of the imaging holder 231. Depending on the type of adhesive, an adhesive curing process is further performed.

  As described above, even when the position of the light emitting side end of the lens holder 221 is defined by the outer peripheral surface 34c of the prism 34, imaging is performed with the condensed light emitting side end of the lens holder 221 so that the mark M22 and the mark M32 are aligned. The optical axis center of the optical member of the lens unit 220 and the center of the light received by the light receiving region 33a of the image pickup device 33 of the image pickup unit 230 are matched by simply fitting the collected light incident side end of the holder 231 together. Further, the position of each holder in the axis L2 direction and the circumferential direction around the axis L2 can be accurately defined.

(Embodiment 3)
Next, Embodiment 3 will be described. In the third embodiment, a case will be described in which the position of the condensed light emission side end portion of the lens holder is defined by a cylindrical projection formed on the light incident surface of the prism.

  FIG. 6 is an exploded perspective view of the imaging module according to the third embodiment, and FIG. 7 is a cross-sectional view of the imaging module shown in FIG. 6, which is perpendicular to the light receiving region surface of the imaging device that constitutes the imaging module. It is sectional drawing at the time of cut | disconnecting in a smooth surface. As shown in FIGS. 6 and 7, the imaging module 315 according to the third embodiment includes a lens unit 320 and an imaging unit 330 having an imaging element 33.

  The lens unit 320 includes a hollow cylindrical lens holder 321 having both ends opened, lenses 222 and 223 that collect external light, and an observation window 224 that transmits external light. The opening size of the lens holder 321 is a size that matches the outer periphery of the lenses 222 and 223 and the observation window 224. As shown in FIGS. 7 (1) and 7 (2), the lenses 222 and 223 and the observation window 224 are arranged. Are assembled in the lens holder 321 so that their centers are located coaxially with the outer diameter central axis of the lens holder 321. Light from the outside that enters the lens holder 321 through the observation window 224 from the opening 321a at the end of the lens holder 321 is condensed by the lenses 222 and 223, and this condensed light is collected at the other end of the lens holder 321. The light is emitted from the opening 321b. The lens holder 321 is made of, for example, corrosion resistant steel, and at least the outer side is shielded from light.

  The imaging unit 330 includes a hollow imaging holder 331 that is open at both ends, an imaging element 33 that is mounted on the substrate 32, and a prism 334 that is placed on the imaging element 33. The imaging holder 331 is made of, for example, corrosion resistant steel.

  The prism 334 has a shape in which a cylindrical protrusion 334e is formed on a light incident surface 334a that is one side surface of a triangular prism. The outer diameter of the protrusion 334e is set to coincide with the inner diameter of the collected light exit end on the opening 321b side of the lens holder 321.

  Similar to the imaging holder 231, the imaging holder 331 has a shape in which a cylinder protrudes from one side surface of a prism, the column part has a substantially hollow cylindrical shape, and the prism part has a hollow hollowed out a prism having a trapezoidal bottom surface. Has a shape.

  The size of the opening 331b in the prismatic portion of the imaging holder 331 is set so that it can be assembled inside the imaging holder 331 via the opening 331b in a state where the substrate 32, the imaging device 33, and the prism 334 are mounted. Is done. The substrate 32, the imaging element 33, and the prism 334 are assembled inside the imaging holder 331 by fixing a part of the bottom surface of the substrate 32 to the inner peripheral surface of the imaging holder 331. For example, when the optical members of the imaging holder 331 are assembled, the shapes of the optical members and the imaging holder 331 are designed so that the point C23 of the prism 334 is positioned on the outer diameter central axis of the imaging holder 331. This point C23 corresponds to the center of the reference region, which is the region where the light received by the light receiving region 33a of the image sensor 33 is incident, of the surface 334f of the protrusion 334e of the light incident surface 334a. As in the first embodiment, the prism 334 is configured so that the light passing through the point C23 of the prism 334 reaches the center C1 of the light receiving region 33a of the image sensor 33, as shown in FIG. It is mounted on the image sensor 33.

  The inner diameter of the circular opening 331 a of the cylindrical portion of the imaging holder 331 to which the condensed light emitted from the lens unit 320 is incident is larger than the outer diameter of the lens holder 321. For this reason, as shown by the arrow in FIG. 7A, the light emitting side end of the lens holder 321 is fitted into the imaging holder 331 via the opening 331 a of the columnar portion of the imaging holder 331, whereby the lens holder The light emitting side end of 321 and the light incident side end of the imaging holder 331 can be directly fitted as shown in FIG.

  Here, when the lens holder 321 and the imaging holder 331 are fitted to the light emitting side end of the lens holder 321 and the light incident side end of the imaging holder 331, the optical axis of the lens unit 320 passing through the center C32 of the lens 222. The shape is designed so that the center passes through the point C23 of the prism 334 fixed inside the imaging holder 321. Further, the inner diameter 321 c of the lens holder 321 is formed so that the inner diameter of the opening 321 b of the lens holder 321 coincides with the outer diameter of the protrusion 324 e of the light incident surface 334 a of the prism 334. The position of the lens holder 321 in the vertical direction in the drawing of FIG. 7B is defined by directly fitting on the outer peripheral surface 334c of the portion 324e. When the light emitting side end of the lens holder 321 and the light incident side end of the imaging holder 331 are fitted, the center of the optical axis of the lens unit 320 passing through the center C32 of the lens 222 and the point C23 of the prism 334 are the same. The inner peripheral surface 321c at the light emitting side end of the lens holder 321 is directly positioned by the outer peripheral surface 334c of the projection 334e of the prism 334 so as to be positioned on the axis L3. Since the prism 334 is mounted on the image sensor 33 so that the light passing through the point C23 reaches the center C1 of the light receiving region 33a, the light emission side end of the lens holder 321 and the light incident on the image holder 331 are provided. At the time of fitting with the side end portion, the optical axis center of the optical member of the lens unit 320 and the center of the light received by the light receiving region 33a of the imaging element 33 of the imaging unit 330 coincide with each other. A part of the outer peripheral surface of the light emitting side end of the lens holder 321 is also defined by a part of the inner peripheral surface of the imaging holder 331.

  The end of the condensed light exit side of the lens holder 321 is positioned in the direction of the axis L3 by the tip 321f being applied to the light incident surface 334a of the prism 334. Further, as in the first embodiment, as shown in FIG. 6, the condensed light exit side end outer peripheral surface of the lens holder 321 and the light incident side end outer peripheral surface of the imaging holder 331 are arranged in the direction of the axis L3 and A triangular mark M23 and a triangular mark M33 for defining the position of each holder in the circumferential direction of the holder (circumferential direction about the axis L3) are respectively attached.

  At the time of assembly, first, an adhesive is applied to the inner peripheral surface 321c of the emission side end of the lens holder 321. Next, the lens holder 321 is fitted into the imaging holder 331 so that the vertex of the mark M23 of the lens holder 321 and the vertex of the mark M33 of the imaging holder 331 are coaxial with each other when viewed from above. Then, the imaging holder 331 is inserted into the lens holder 321 until the tip 321f of the end of the condensed light exit side of the lens holder 321 contacts the light incident surface 334a of the prism 334. Depending on the type of adhesive, an adhesive curing process is further performed.

  Thus, even when the light emitting side end of the lens holder 321 is positioned on the outer peripheral surface 334c of the projection 334e of the prism 334, the condensed light emitting side of the lens holder 321 is aligned so that the mark M23 and the mark M33 are aligned. The lens holder 321 is held until the end portion 321f of the lens holder 321 is brought into contact with the light incident surface 334a of the prism 334 by fitting the end portion with the collected light incident side end portion of the imaging holder 331. Just by inserting it into the imaging holder 331, the optical axis center of the optical member of the lens unit 320 and the center of the light received by the light receiving region 33a of the imaging device 33 of the imaging unit 330 are made to coincide with each other. The position in the circumferential direction around L3 can be accurately and easily defined.

(Modification of Embodiment 3)
Next, a modification of the third embodiment will be described. In the modification of the third embodiment, a case will be described in which the position of the condensing light emitting side end portion of the lens holder is defined by a frame-shaped protrusion formed on the light incident surface of the prism.

  8 is an exploded perspective view of an imaging module according to a modification of the third embodiment. FIG. 9 is a cross-sectional view of the imaging module shown in FIG. It is sectional drawing at the time of cut | disconnecting with respect to a perpendicular | vertical surface. As shown in FIGS. 8 and 9, the imaging module 3151 according to the third embodiment includes a lens unit 320 and an imaging unit 3301 having an imaging element 33.

  The imaging unit 3301 includes a hollow imaging holder 3311 having both ends opened, an imaging element 33 mounted on the substrate 32, and a prism 3341 placed on the imaging element 33. The imaging holder 3311 is made of, for example, corrosion resistant steel.

  The prism 3341 has a prismatic shape in which the light incident surface 3341a has a trapezoidal shape, and the light incident surface 3341a has an inner diameter that matches the outer diameter of the collected light emitting side end on the opening 321b side of the lens holder 321. A frame-shaped protrusion 3241e is formed. When viewed from the light incident direction side, the prism 3341 has a circle on the light incident surface of the prism 3341 having a diameter that matches the outer diameter of the end of the condensed light exit side on the opening 321b side of the lens holder 321. It appears that a shaped opening is formed.

  Similar to the imaging holder 231, the imaging holder 3311 has a shape in which a cylinder protrudes from one side surface of a prism, the column part has a substantially hollow cylindrical shape, and the prism part has a hollow hollowed out a prism having a trapezoidal bottom surface. Has a shape.

  The size of the opening 3311b in the prism portion of the imaging holder 3311 is set so that it can be assembled inside the imaging holder 3311 through the opening 3311b in a state where the substrate 32, the imaging device 33, and the prism 3341 are mounted. Is done. The substrate 32, the image sensor 33, and the prism 3341 are fixed to the inner peripheral surface of the imaging holder 3311 by fixing a part of the bottom surface of the substrate 32 and a part of the outer peripheral surface of the prism 3341 to the light incident surface 3341 a. Can be assembled. For example, when the optical members of the imaging holder 3311 are assembled, the shapes of the optical members and the imaging holder 3311 are designed so that the point C231 of the light incident surface 3341a of the prism 3341 is positioned on the outer diameter central axis of the imaging holder 3311. Has been. This point C231 corresponds to the center of a reference area, which is an area where light received by the light receiving area 33a of the image sensor 33 is incident, of the light incident surface 3341a. As in the first embodiment, as shown in FIG. 9B, in the prism 3341, the light passing through the center C231 of the light incident surface 3341a of the prism 3341 is the center C1 of the light receiving region 33a of the image sensor 33. It is mounted on the image sensor 33 so as to reach.

  The inner diameter of the opening 3311 a of the cylindrical portion of the imaging holder 3311 on which the condensed light emitted from the lens unit 320 is incident is larger than the outer diameter of the lens holder 321. For this reason, as shown by the arrow in FIG. 9 (1), the light emitting side end of the lens holder 321 is fitted into the imaging holder 3311 through the opening 3311a of the cylindrical portion of the imaging holder 3311, whereby the lens holder The light emitting side end of 321 and the light incident side end of the imaging holder 3311 can be directly fitted as shown in FIG.

  When the lens holder 321 and the imaging holder 3311 are fitted to the light emitting side end of the lens holder 321 and the light incident side end of the imaging holder 3311, the optical axis center of the lens unit 320 passing through the center C32 of the lens 222 is The shape is designed so as to pass through the point C231 of the prism 3341 fixed inside the imaging holder 3311. Further, the outer diameter of the opening 321 b of the lens holder 321 and the inner diameter of the protrusion 3341 e of the light incident surface 3341 a of the prism 3341 are formed so that the outer peripheral surface 321 g of the lens holder 321 is the protrusion of the prism 3341. By directly fitting on the inner peripheral surface 3341f of the portion 3341e, the position of the lens holder 321 in the vertical direction in FIG. 9B is defined. When the light emitting side end of the lens holder 321 and the light incident side end of the imaging holder 3311 are fitted, the center of the optical axis of the lens unit 320 passing through the center C32 of the lens 222 and the point C231 of the prism 3341 are the same. The outer peripheral surface 321g of the light emitting side end of the lens holder 321 is directly positioned by the inner peripheral surface 3341f of the protrusion 3341e of the prism 3341 so as to be positioned on the axis L4. Since the prism 3341 is mounted on the imaging element 33 so that the light passing through the point C231 reaches the center C1 of the light receiving region 33a, the light emitting side end of the lens holder 321 and the light incident side end of the imaging holder 3311 are mounted. At the time of fitting with the optical unit, the center of the optical axis of the optical member of the lens unit 320 and the center of the light received by the light receiving region 33a of the imaging element 33 of the imaging unit 3301 coincide.

  Then, the position of the lens holder 321 in the direction of the axis L4 is defined by the end 321f of the lens holder 321 being brought into contact with the light incident surface 3341a of the prism 3341. As in the first embodiment, as shown in FIG. 8, the condensed light exit side end outer peripheral surface of the lens holder 321 and the light incident side end outer peripheral surface of the imaging holder 3311 are arranged on the axis L4 of each holder. A triangular mark M231 and a triangular mark M331 are provided for defining the position of each holder in the circumferential direction centered on.

  At the time of assembly, first, an adhesive is applied to the outer peripheral surface 321g of the exit side end of the lens holder 321. Next, the lens holder 321 is fitted into the imaging holder 3311 so that the vertex of the mark M231 of the lens holder 321 and the vertex of the mark M331 of the imaging holder 3311 are coaxial when viewed from above. Then, the imaging holder 3311 is inserted into the lens holder 321 until the tip 321f of the end of the condensed light exit side of the lens holder 321 contacts the light incident surface 3341a of the prism 3341. Depending on the type of adhesive, an adhesive curing process is further performed.

  As described above, when the position of the light emitting side end of the lens holder 321 is defined by the inner peripheral surface 3341f of the protrusion 3341e of the prism 3341, the condensing light emitting side end of the lens holder 321 is the same as the imaging module 315. The imaging module 3151 can be manufactured simply and accurately by simply inserting the lens holder 321 into the imaging holder 3311 until the tip 321f of the lens 311 comes into contact with the light incident surface 3341a of the prism 3341.

  In addition, like the prism 3342 shown in FIG. 10, a circle having an outer diameter that further matches the inner diameter of the end portion of the condensing light emission side on the opening 321 b side of the lens holder 321 further on the inner peripheral side of the protrusion 3341 e. A columnar protrusion 3342e is formed, and the outer peripheral surface 321g and the inner peripheral surface 321c of the light emitting side end of the lens holder 321 are defined by the inner peripheral surface of the protrusion 3341e and the outer peripheral surface of the protrusion 3342e of the prism 3342. May be. In this case, as shown by an arrow in FIG. 10A, the light emission side end of the lens holder 321 is fitted into the light incident side end of the imaging holder 3311, and the tip 321 f of the condensed light emission side end of the lens holder 321. However, the image pickup module 3152 shown in FIG. 10 (2) can be simply and accurately inserted by simply inserting the lens holder 321 into the image pickup holder 3311 until it touches the bottom of the groove 3342h between the protrusion 3341e and the protrusion 3342e of the prism 3342. Can be manufactured.

  Further, like the imaging module 3153 in FIG. 11, the light incident surface 34 a of the prism 34 assembled to the imaging holder 3313 of the imaging unit 3303 is connected to the tip 321 f of the condensed light emission side end of the lens holder 321 of the lens unit 320. The imaging module size may be further reduced by directly adhering to the substrate. Further, as in the imaging module 3154 of FIG. 12, a hollow cylindrical projection 3344i having the same shape as the lens holder 321 is integrally formed on the light incident surface 3344a of the prism 3344, and the projection 3344i is formed inside the projection 3344i. Lenses 222 and 223 and an observation window 224 may be incorporated.

  In the first to third embodiments, the prisms 34, 334, 3341, 3342, and 3344 have been described as examples of the optical member placed on the image sensor 33. However, the present invention is not limited to this. For example, as in the imaging module 415 illustrated in FIG. 13, a plate glass 434 that transmits the condensed light emitted from the lens holder 21 to the imaging element 433 may be used.

  In this case, when the imaging module 415 is completed, the substrate 432 on which the imaging element 433 is mounted is assembled inside the imaging holder 431 of the imaging unit 430 so that the optical axis of the lens unit 20 and the surface of the light receiving region 433a are orthogonal to each other. The plate glass 434 is mounted on the image sensor 433 so that the center C2 ′ of the light incident surface 434a of the plate glass 434 and the center C1 ′ of the light receiving region 433a of the image sensor 433 are located on the same axis. Is done. The center C2 ′ corresponds to the center of the reference region, which is a region where light received by the light receiving region 433a is incident, of the light incident surface 434a of the plate glass 434. The plate-like glass 434 has a substantially cylindrical shape, and the outer diameter of the plate-like glass 434 coincides with the inner diameter of the light emitting side end of the lens holder 21. For this reason, when the inner peripheral surface of the lens holder 21 is fitted into the outer peripheral surface 434j of the plate glass 434, the optical axis center of the lens unit 20 passing through the center C3 of the lens 22 and the center C2 ′ of the plate glass 434 The lens holder 21 is positioned so that the center C1 ′ of the light receiving region 433a of the image sensor 433 is positioned on the same axis.

  In the first to third embodiments, the imaging module mounted on the distal end portion of the insertion tool of the endoscope apparatus has been described as an example. Of course, the imaging module includes an imaging function including a digital camera and a digital video camera. The present invention can be applied to various types of electronic imaging devices such as mobile phones.

DESCRIPTION OF SYMBOLS 1 Endoscope apparatus 2 Insertion part 3 Operation part 4 Universal code 5 Tip part 6 Bending part 7 Flexible pipe part 8 Connector part 9 Light guide connector 10 Electrical contact part 11 Air supply mouthpiece 12 Bending knob 13 Treatment tool insertion part 14 Switch 15, 215, 315, 3151, 3152, 3153, 3154, 415 Imaging module 20, 220, 320 Lens unit 21, 221, 321 Lens holder 22, 23, 222, 223 Lens 24, 224 Observation window 30, 230, 330, 3301, 3303 Imaging unit 31, 231, 331, 3311, 3313, 431 Imaging holder 32, 432 Substrate 33, 433 Imaging element 33a, 433a Light receiving area 34, 334, 3341, 3342, 3344 Prism 34a Light incident surface 35 Wire 36 Parts 37 Line cable 434 plate-shaped glass

Claims (3)

A hollow lens holder open at both ends;
A lens assembled inside the lens holder and collecting light incident from one end of the lens holder;
A hollow imaging holder having an opening through which light emitted from the lens is incident;
An optical member that is assembled inside the imaging holder and transmits or refracts light incident from one end of the imaging holder, and has a size that matches a light incident surface with an inner peripheral surface of a light emitting side end of the lens holder. An optical member on which a protrusion is formed;
An imaging element that is assembled inside the imaging holder and has a light receiving region formed on the surface thereof that receives and transmits light transmitted or refracted by the optical member;
With
The opening shape of the light emitting side end of the lens holder is the same as the shape of the light incident surface of the protrusion, and the light emitting side end of the lens holder has an inner peripheral surface of the protrusion. Hamama is, part of the outer peripheral surface of the light exit side end of the lens holder, by whose position is defined by contact with a portion of the inner peripheral surface of the image holder, and optical axis center of the lens An imaging module, wherein the center of the light received in the light receiving region of the imaging element coincides with the tip of the optical element being abutted against the light incident surface of the optical member, thereby defining an axial position. The imaging module according to claim 1 , wherein marks that define the positions of the holders in the axial direction are respectively attached to the outer peripheral surface of the lens holder and the outer peripheral surface of the imaging holder. The imaging module according to claim 1 or 2 , wherein the imaging module is mounted at a distal end portion of an endoscope apparatus inserted into a living body.

Images