JP6322120B2 - Imaging apparatus and endoscope using the same - Google Patents

Description

  The present invention relates to an imaging apparatus in which various cables are electrically connected to an imaging device via a flexible printed circuit board, and an endoscope using the imaging apparatus.

  2. Description of the Related Art In recent years, in an image sensor used for a distal end portion of an electronic endoscope or the like, an increase in the number of pixels and a reduction in size associated with a reduction in pixel size have been promoted. With such downsizing of the image sensor, it is required to efficiently reduce the package size of the image pickup apparatus using the image sensor. As a technique for reducing the size of an imaging apparatus, for example, in Patent Document 1, electronic parts such as capacitors, resistors, and transistors are mounted, and lands for connection with various cables such as a signal cable and a power cable are formed. A technique for disposing a flexible printed circuit board (FPC board) to be arranged on the back side of an imaging element in a state of being bent into a predetermined shape is disclosed.

  By the way, when the number of pixels of the image sensor is increased, the operating frequency for the image sensor is increased, and the signal amount is reduced. Therefore, in an image pickup apparatus using an image pickup device with an increased number of pixels, the video output tends to be affected by disturbances and noise from mounted components, and the signal-to-noise ratio (SN ratio) on the image tends to deteriorate. In addition, when the image pickup device is downsized, it is necessary to arrange wiring for connection with the image pickup device on the FPC board with a narrow line width and high density. Therefore, in an imaging apparatus using a miniaturized imaging device, the wiring in the section from the cable connection land to the imaging device is likely to be affected by noise, and the SN ratio on the image tends to be further deteriorated. .

  Here, the deterioration of the S / N ratio accompanying the increase in the number of pixels of the image sensor as described above can be suppressed, for example, by disposing the capacitor for stabilizing the image sensor drive power supply on the circuit at a position close to the image sensor. It is. Further, the deterioration of the SN ratio accompanying the downsizing of the image sensor as described above can be suppressed by arranging the cable connection land at a position close to the image sensor.

JP 2010-268077 A

  However, if the capacitor for stabilizing the image sensor driving power supply and the cable connection land are both arranged in the vicinity of the image sensor, it is necessary to take measures such as extending the width of the FPC board. There is a risk of increasing the package size.

  The present invention has been made in view of the above circumstances, and provides an imaging apparatus capable of realizing a good signal-to-noise ratio without increasing the package size and an endoscope using the same. Objective.

An image pickup apparatus according to an aspect of the present invention includes an image pickup device, a flexible printed circuit board provided with an element connecting portion that is electrically connected to the image pickup device, and the flexible printed circuit board adjacent to the element connecting portion. A land forming area set in the area, a cable connecting land formed in the land forming area, and an area on the flexible printed circuit board spaced from the element connecting portion, and the flexible printed circuit board is folded back. Accordingly, an overlapping region arranged at a position overlapping with the land forming region, an image sensor driving power supply stabilization capacitor mounted in the overlapping region, and a conductive path in the overlapping direction of the land forming region and the overlapping region And electrically connecting the capacitor for stabilizing the imaging element driving power source to the element connecting portion. When, those having a.
An endoscope according to an aspect of the present invention includes the imaging device according to any one of claims 1 to 7 at a distal end portion provided at a distal end of an insertion portion.

  According to the imaging apparatus of the present invention, it is possible to realize a good signal-to-noise ratio without increasing the package size.

1 is a schematic configuration diagram of an electronic endoscope according to a first embodiment of the present invention. Same as above, sectional view of main part of imaging unit Same as above, side view of imaging device Same as above, perspective view of imaging device Same as above, development of flexible printed circuit board Same as above, sectional view taken along line VI-VI in FIG. The perspective view of an imaging device concerning a 1st modification same as the above. As above, the first embodiment is a development view of the flexible printed circuit board. The perspective view of an imaging device concerning a 2nd modification same as the above. As above, the second embodiment is a development view of the flexible printed circuit board. The perspective view of an imaging device concerning a 3rd modification same as the above. As above, the third embodiment is a development view of the flexible printed circuit board. The perspective view of an imaging device concerning a 4th modification same as the above. Same as above, development of flexible printed circuit board according to the fourth modification The perspective view of an imaging device concerning the 2nd Embodiment of this invention. Same as above, development of flexible printed circuit board The side view of an imaging device concerning the 3rd Embodiment of this invention. Same as above, development of flexible printed circuit board

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 6 relate to a first embodiment of the present invention, FIG. 1 is a schematic configuration diagram of an electronic endoscope, FIG. 2 is a cross-sectional view of a main part of an imaging unit, FIG. 3 is a side view of an imaging apparatus, and FIG. 4 is a perspective view of the image pickup apparatus, FIG. 5 is a development view of the flexible printed circuit board, and FIG. 6 is a cross-sectional view of a principal part taken along line VI-VI in FIG.

  An electronic endoscope (endoscope) 1 shown in FIG. 1 is connected to a long insertion portion 2, an operation portion 3 connected to the base end of the insertion portion 2, and a light source device (not shown). The light guide connector 4 and a video connector 5 connected to a video system center (not shown, camera control unit, also referred to as CCU) are configured. In the electronic endoscope 1, the operation unit 3 and the light guide connector 4 are connected via a flexible cable (also referred to as a universal cord) 6, and the light guide connector 4 and the video connector 5 are flexible. It is connected via a communication cable 7.

  The insertion portion 2 is provided with a distal end portion 11 mainly composed of a metal member such as stainless steel, a bending portion 12 and a rigid tube 13 composed of a metal tube such as stainless steel in order from the distal end side. Yes. This insertion portion 2 is a portion to be inserted into the body, and the distal end portion 11 incorporates an imaging unit 20 (see FIG. 2). In addition, inside the bending portion 12 and the rigid tube 13, an imaging cable bundle 27 (see FIG. 2) that is electrically connected to the imaging unit 20, a light guide bundle (not shown) that transmits illumination light to the distal end portion 11, and the like. Is inserted. In addition, although the electronic endoscope 1 of this embodiment has illustrated the rigid endoscope by which the base end side was comprised with the rigid tube 13 rather than the bending part 12, it is not limited to this, The bending part 12 Alternatively, the endoscope may be a flexible endoscope that is configured by a flexible tube having flexibility on the proximal end side.

  The operation unit 3 includes an angle lever 14 for remotely operating the bending unit 12 and various switches 16 for operating the light source device, the video system center, and the like. The angle lever 14 is a bending operation means that can operate the bending portion 12 of the insertion portion 2 in four directions, up, down, left, and right here. Note that the bending portion 12 is not limited to a configuration that can be bent in four directions, up, down, left, and right, and may be configured to be capable of bending in only two directions, for example, up and down.

  Next, the configuration of the imaging unit 20 built in the distal end portion 11 of the electronic endoscope 1 will be described in detail with reference to FIG.

  As shown in FIG. 2, the imaging unit 20 is provided with an objective optical unit 21, an element frame 22 connected to the base end side of the objective optical unit 21, and a base end side of the element frame 22. The shield frame 23, the heat shrinkable tube 24 sheathed on the shield frame 23, the imaging device 25 held in the element frame 22 and accommodated in the shield frame 23, and the imaging device 25 filled in the shield frame 23 And an insulating sealing resin 26 for sealing.

  The objective optical unit 21 includes, for example, optical members such as a plurality of optical lenses 21a and a diaphragm 21b, and a lens frame 21c that holds the optical lenses 21a and the diaphragm 21b.

  The element frame 22 is configured by a cylindrical member made of stainless steel, for example. The distal end side of the element frame 22 is externally fitted to the proximal end side of the lens frame 21 c, whereby the element frame 22 is continuously provided on the optical axis O of the objective optical unit 21.

  The shield frame 23 is configured by a substantially cylindrical member formed by bending a stainless steel thin plate, for example. The front end side of the shield frame 23 is externally fitted to the element frame 22, and thereby, an accommodation chamber 23 a for accommodating the imaging device 25 is formed behind the element frame 22.

  The image pickup apparatus 25 includes, for example, an image pickup element 30 made of a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), and the like, and a flexible printed circuit board (FPC board) 35 electrically connected to the image pickup element 30. , And is configured.

  As shown in FIGS. 2 to 4, the image sensor 30 has a substantially rectangular plate shape, and a substantially square light receiving surface 30 a is provided on the front surface of the image sensor 30 so as to be biased to one side. A first cover glass 31 and a second cover glass 32 are stacked and adhered to the light receiving surface 30a. Among these, the second cover glass 32 positioned forward is fitted into the base end side of the element frame 22. (See FIG. 2). Thereby, the image sensor 30 is held at the imaging position of the objective optical unit 21. A plurality of bonding pads 30b are arranged in a line on the other side adjacent to the light receiving surface 30a on the front surface of the imaging element 30.

  For example, as shown in FIG. 6, the FPC board 35 includes a base material 35a formed of polyimide or the like, a wiring pattern 35b formed on both surfaces of the base material 35a, and a resist laminated on the upper layer of the wiring pattern 35b. 35c.

  As shown in FIG. 5, the FPC board 35 of this embodiment has a substantially L shape in plan view, and an element connection in which the resist 35c is removed over the entire area at one end in the longitudinal direction of the FPC board 35. A portion 37 is formed. A plurality of element connection lands 37a are arranged in a line at one end of the element connection portion 37 (hereinafter referred to as the front surface side). The FPC board 35 is connected to the image sensor 30 by electrically connecting the element connection lands 37 a to the bonding pads 30 b on the image sensor 30.

  On the FPC substrate 35, a first substrate region 40 as a land formation region is set in a region on one end side adjacent to the element connection portion 37. In addition, a second substrate region 41 that is connected to the first substrate region 40 through the first bent portion 45 is set on the other end side on the FPC substrate 35. Further, on the side of the other end side on the FPC board 35, a third board area 42 is set so as to be connected to the second board area via the second bent portion 46.

  On the other surface side (hereinafter referred to as the back surface side) of the first substrate region 40, a part of the resist 35c is appropriately removed and a part of the wiring pattern 35b is exposed, thereby connecting a plurality of cables. A land 40a is formed. Here, as shown in FIG. 2, the distal end side of the imaging cable bundle 27 is inserted into the accommodation chamber 23 a from the rear part of the shield frame 23. Various cables 27a such as signal cables and power cables branched from the imaging cable bundle 27 are electrically connected to each cable connection land 40a by soldering or the like.

  A plurality of lands 48 for mounting electronic components (see FIG. 6) are formed on the surface side of the second and third substrate regions 41 and 42 by partly removing the resist 35c. A plurality of electronic components are mounted on the surface side of the second and third substrate regions 41 and 42 by soldering to the electronic component mounting land 48.

  Here, in the second substrate region 41, for example, as an electronic component, for example, a digital IC 50 for generating a drive signal of the image sensor 30 and an IC drive power supply stabilization capacitor for stabilizing the drive power of the digital IC 50 51, a resistor 52, and the like are mounted.

  Further, in the third substrate region 42, as electronic components, for example, an analog IC 53 for amplifying a video signal from the image sensor 30, and an image sensor drive power source stabilization for stabilizing the image sensor 30 drive power source. A capacitor 54, a resistor 55, and the like are mounted. In this case, in the image sensor driving power supply stabilization capacitor 54, for example, only the ground side terminal 54b is soldered to the electronic component mounting land 48, and the power supply side terminal 54a is not soldered. It is mounted on the third substrate region 42.

  In the FPC board 35 on which various electronic components are mounted in this manner, for example, as shown in FIGS. 2 to 4, the first bent portion 45 is bent into a valley fold with reference to the surface side of the FPC board 35. The second bent portion 46 is bent in a mountain fold with reference to the surface side of the FPC board 35. The imaging device 25 causes the second and third substrate regions 41 and 42 to overlap with each other in the projection plane of the first substrate region 40 by bending the first and second bent portions 45 and 46. Are stored in the storage chamber 23a.

  In addition, since the second and third substrate regions 41 and 42 are arranged so as to overlap the first substrate region 40, the imaging element driving power source stabilization capacitor 54 is disposed in the vicinity of the element connection portion 37. Yes. Here, for example, as shown in FIG. 5, a capacitor connection land 49 is formed on the surface side of the element connection portion 37 by a wiring pattern 35b. The capacitor connection land 49 is electrically connected to a cable connection land 47 to which a power supply cable 27 a to the FPC board 35 is connected and a power supply element connection land 37 a to the image sensor 30. Yes. Further, as shown in FIGS. 3 and 4, a cable 56 serving as a conductive portion extending to form a conductive path in the overlapping direction of the first to third substrate regions 40 to 42 is provided on the capacitor connection land 49. The terminal 54a on the power supply side of the image sensor driving power stabilization capacitor 54 is electrically connected. As a result, the power supply side terminal 54a of the imaging element drive power stabilization capacitor 54 does not go through the first to third substrate regions 40 to 42, and the predetermined cable connection land 47 and element connection land. 37a is electrically connected. Therefore, a stable drive power source that is less affected by noise or the like is supplied to the image sensor 30.

  According to such an embodiment, the first board area 40 (land formation area) is set in the area on the FPC board 35 adjacent to the element connection portion 37 that is electrically connected to the image pickup element 30 to connect the cable. A third substrate region 42 (superimposed) is formed on the FPC substrate 35, which is formed on the FPC substrate 35, and is formed on the FPC substrate 35 by folding the FPC substrate 35. The image sensor driving power source stabilization capacitor 54 is mounted in the region), and the image sensor driving power source stabilization capacitor 54 is connected to the cable 56 that forms a conductive path in the overlapping direction of the first to third substrate regions 40 to 42. By electrically connecting to the element connection portion 37 via the, a good signal-to-noise ratio can be realized without increasing the package size.

  In other words, the third substrate region 42 on which the image sensor driving power supply stabilization capacitor 54 is mounted is superimposed on the first substrate region 40 on which the cable connection land 47 is formed, whereby the image sensor 30. Without increasing the width of the FPC board 35 with respect to the width of the FPC board 35, the cable connection land 47 and the image sensor driving power supply stabilization capacitor 54 are physically close to the image sensor 30 (element connection portion 37). Can be arranged. The imaging element driving power supply stabilizing capacitor 54 (terminal 54a) is connected to the element connecting portion 37 (for capacitor connection) via a cable 56 that forms a conductive path in the overlapping direction of the first to third substrate regions 40 to 42. By electrically connecting with the land 49), not only the cable connection land 47 but also the terminal 54a on the power supply side of the image sensor driving power stabilization capacitor 54, the second and third substrate regions 41, It is possible to connect to the image sensor 30 (element connection unit 37) at a position close to the circuit without passing through 42 or the like. Therefore, the package size is increased, for example, the request for suppressing the deterioration of the SN ratio accompanying the increase in the number of pixels of the image pickup device 30 and the request for suppressing the deterioration of the SN ratio accompanying the downsizing of the image pickup device 30. Can be compatible.

  In this case, the imaging element drive power supply stabilization capacitor 54 is mounted at a position farthest from the element connection portion 37 when the FPC board 35 is unfolded, and accordingly, other components such as a digital IC 50 and an analog IC 53 are provided. These electronic components can be arranged as close to the element connecting portion 37 as possible, and the influence of noise on these electronic components can also be reduced.

  Here, in the above-described embodiment, an example of the configuration in which the capacitor connection land 49 is formed in the element connection portion 37 has been described. For example, as shown in FIGS. It is also possible to form a connection land 49 and to electrically connect the imaging element drive power supply stabilization capacitor 54 to the element connection portion 37 through a part of the first substrate region 40.

  In the above-described embodiment, an example of the configuration in which the cable 56 is directly connected to the imaging element driving power supply stabilization capacitor 54 has been described. For example, as illustrated in FIGS. It is also possible to form a land 57 in the substrate region 42 and connect the cable 56 to the terminal 54 a on the power supply side of the capacitor 54 for stabilizing the image sensor driving power supply via the land 57.

  Further, in order to avoid the extension of the cable 56 in the width direction of the FPC board 35, for example, as shown in FIGS. 11 and 12, interference with the cable 56 is avoided in the second board area 41 on the FPC board 35. It is also possible to form a notch 41a for this purpose, or as shown in FIGS. 13 and 14, a through hole for avoiding interference with the cable 56 in the second board region 41 on the FPC board 35. It is also possible to form 41b.

  Next, FIGS. 15 and 16 relate to a second embodiment of the present invention, FIG. 15 is a perspective view of an imaging apparatus, and FIG. 16 is a development view of a flexible printed circuit board. Note that this embodiment is mainly different from the first embodiment described above in that a part of the flexible printed circuit board is used as the conductive portion instead of the cable 56. In addition, about the structure similar to the above-mentioned 1st Embodiment, a same sign is attached | subjected and description is abbreviate | omitted.

  As shown in FIGS. 15 and 16, a capacitor connection land 49 is formed in the first substrate region 40 by removing a part of the resist 35c.

  On the other hand, a conductive circuit portion 60 extends from the third substrate region 42. The conductive circuit section 60 has, for example, an elongated band shape, and is electrically connected to the power supply side terminal 54 a of the imaging element drive power supply stabilization capacitor 54 in the third substrate region 42.

  The conductive circuit portion 60 is electrically connected to the capacitor connection land 49 at one end side by soldering or the like, thereby forming a conductive path in the overlapping direction of the first to third substrate regions 40 to 42. It functions as a conductive part.

  According to such an embodiment, since the conductive path can be formed without using a cable or the like, in addition to the effect of the first embodiment described above, there is an effect that the structure can be further simplified.

  Next, FIGS. 17 and 18 relate to a third embodiment of the present invention, FIG. 17 is a side view of an imaging apparatus, and FIG. 18 is a development view of a flexible printed circuit board. Note that the present embodiment is mainly different from the first embodiment described above in the arrangement of the imaging element drive power supply stabilization capacitor 54 and the like. In addition, about the structure similar to the above-mentioned 1st Embodiment, a same sign is attached | subjected and description is abbreviate | omitted.

  Here, in the imaging device 25 of the present embodiment, the digital IC and the accompanying IC driving power supply stabilization capacitor and the like are omitted, and a driving signal for the imaging device 30 is generated on the FPC board 35. Without being directly input via the cable 27a.

  As shown in FIGS. 17 and 18, the second substrate region 41 connected to the first substrate region 40 via the first bent portion 45 is provided on the other end side on the FPC substrate 35 of the present embodiment. Is set.

  In the second substrate region 41, as electronic components, for example, an analog IC 53 for amplifying a video signal from the image sensor 30, and an image sensor drive power supply stabilization capacitor for stabilizing the drive power of the image sensor 30 54, a resistor 55, and the like are mounted. In this case, for example, only the ground side terminal 54b is soldered to the electronic component mounting land 48 and the power supply side terminal is not soldered. It is mounted on the second substrate area 41.

  In the FPC board 35 on which various electronic components are mounted in this way, the first bent portion 45 is bent in a valley fold with respect to the surface side of the FPC board 35. Then, due to the bending of the first bending portion 45, the imaging device 25 causes the accommodation chamber in a state where the second substrate region 41 is superimposed on the projection surface of the first substrate region 40 as a superimposed region. 23a.

  In addition, since the second substrate region 41 is disposed so as to overlap the first substrate region 40, the imaging element drive power supply stabilization capacitor 54 is sandwiched between the first and second substrate regions 40, 41. In the state, it is disposed in the vicinity of the element connecting portion 37. Here, for example, as shown in FIG. 18, the capacitor connection land 49 is provided on the front surface side of the first substrate region 40 at a position corresponding to the terminal on the power supply side of the capacitor 54 for stabilizing the imaging element driving power source. Is formed. A terminal 54 a on the power supply side of the capacitor 54 for stabilizing the image sensor driving power supply is electrically connected to the capacitor connection land 49 via the solder portion 61. That is, in the present embodiment, the solder part 61 functions as a conductive part that forms a conductive path.

  According to such an embodiment, since the conductive path can be formed without using a cable or the like, in addition to the effect of the first embodiment described above, there is an effect that the structure can be further simplified.

  In addition, this invention is not limited to each embodiment described above, A various deformation | transformation and change are possible, and they are also in the technical scope of this invention. For example, in the above-described embodiment, an example of an imaging device used for an electronic endoscope has been described. However, the present invention is not limited to this, and for example, a mobile phone or a personal digital assistant (PDA: Personal Digital Terminal) Needless to say, the present invention can be applied to Assistants). Of course, the configurations of the above-described embodiments and modifications may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope 2 ... Insertion part 3 ... Operation part 4 ... Light guide connector 5 ... Video connector 7 ... Communication cable 11 ... Tip part 12 ... Bending part 13 ... Rigid tube 14 ... Angle lever 16 ... Various switches 20 ... Imaging Unit 21 ... Objective optical unit 21a ... Optical lens 21b ... Aperture 21c ... Lens frame 22 ... Element frame 23 ... Shield frame 23a ... Housing chamber 24 ... Heat-shrinkable tube 25 ... Imaging device 26 ... Sealing resin 27 ... Imaging cable bundle 27a ... Cable 30 ... Imaging element 30a ... Light-receiving surface 30b ... Bonding pad 31 ... First cover glass 32 ... Second cover glass 35 ... Flexible printed circuit board 35a ... Substrate 35b ... Wiring pattern 35c ... Resist 37 ... Element connection part 37a ... for device connection Command 40 ... first substrate region (land formation region)
40a: Cable connection land 41: Second substrate area (overlapping area)
41a ... Notch 41b ... Through-hole 42 ... 3rd board | substrate area | region (superimposition area | region)
45 ... 1st bent part 46 ... 2nd bent part 47 ... Land for cable connection 48 ... Land for mounting electronic components 49 ... Land for capacitor connection 50 ... Digital IC
51 ... IC drive power supply stabilization capacitor 52 ... Resistor 53 ... Analog IC
54 ... Capacitor for stabilizing the imaging device driving power supply 54a ... Terminal on the power supply side 54b ... Terminal on the ground side 55 ... Resistance 56 ... Cable (conductive part)
57 ... land 60 ... conductive circuit part (conductive part)
61 ... Solder part (conductive part)

Claims (8)

An image sensor;
A flexible printed circuit board provided with an element connecting portion electrically connected to the imaging element;
A land forming region set in a region on the flexible printed circuit board adjacent to the element connecting portion;
A cable connecting land formed in the land forming region;
An overlapping region that is set in an area on the flexible printed circuit board that is spaced apart from the element connecting portion, and is disposed at a position that overlaps the land forming area by folding the flexible printed circuit board;
A capacitor for stabilizing the imaging device driving power source mounted in the overlapping region;
A conductive portion that forms a conductive path in the overlapping direction of the land forming region and the overlapping region, and electrically connects the imaging element driving power supply stabilizing capacitor to the element connecting portion;
An imaging apparatus comprising:   The imaging apparatus according to claim 1, wherein the capacitor for stabilizing the imaging element driving power supply is mounted at a position farthest from the element connection portion when the flexible printed circuit board is deployed.   The imaging device according to claim 1, wherein the conductive portion is a cable extending in a direction in which the war record land formation region and the overlap region overlap.   The imaging apparatus according to claim 3, wherein the flexible printed circuit board has a cutout portion for avoiding interference with the cable.   The imaging apparatus according to claim 3, wherein the flexible printed circuit board has a through hole for avoiding interference with the cable.   The imaging apparatus according to claim 1, wherein the conductive portion is configured by a part of the flexible printed circuit board.   The imaging element drive power supply stabilization capacitor is mounted on the overlap region so as to be positioned between the land formation region and the overlap region when the overlap region is overlapped on the land formation region. The imaging apparatus according to claim 1, wherein the imaging apparatus is characterized.   An endoscope comprising the imaging device according to any one of claims 1 to 7 incorporated in a distal end portion provided at a distal end of the insertion portion.

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