JP2010069217A - Imaging apparatus for electronic endoscope and electronic endoscope - Google Patents

Abstract

An image quality deterioration of an endoscope image due to driving heat of an electronic component is efficiently and reliably prevented.
An imaging apparatus built in an electronic endoscope includes a lens barrel that holds an objective optical system, a solid-state imaging device, and a signal processing circuit. The signal processing circuit 49 is disposed at a position facing the peripheral surface of the lens barrel 37. The lens barrel 37 and the signal processing circuit 49 are connected to each other by a heat radiation / connection circuit board 44 and a heat conductive adhesive 54. The heat dissipation / connection circuit board 44 includes a mounting portion 45 on which the solid-state imaging device 38 is flip-chip mounted, and a heat dissipation portion 46 that connects the lens barrel 37 and the signal processing circuit 49. The driving heat of the signal processing circuit 49 travels through the heat radiating portion 46 and the heat conductive adhesive 54 of the heat radiation / connection circuit board 44 to quickly warm the lens barrel 37 and consequently the objective optical system 36. The heat radiation cooling of the signal processing circuit 49 and the prevention of condensation of the objective optical system 36 and the like can be achieved at the same time.
[Selection] Figure 4

Description

  The present invention relates to an imaging apparatus for an electronic endoscope and an electronic endoscope.

  Electronic endoscopes used in the medical field and the industrial field incorporate a well-known imaging device. The imaging apparatus includes a solid-state imaging device such as a CCD image sensor and an objective optical system for capturing image light of an observation site in the subject that is incident from an observation window provided at the distal end of the insertion portion of the electronic endoscope. Have. A cover glass is disposed on the surface of the light-receiving portion of the solid-state imaging device with a gap (air gap) for arranging color filters and microlenses.

  The distal end of the insertion part of the medical electronic endoscope has a temperature (˜37 ° C.) that is the same as that in the body cavity that is the subject. On the other hand, the temperature in the insertion portion sometimes becomes 40 ° C. or higher and higher than the body temperature due to driving heat of electronic components such as a solid-state imaging device and a signal processing circuit. Since the performance of electronic components has temperature dependence, there has been a problem of performance degradation due to this driving heat, and consequently, image quality degradation of the endoscope image.

  In addition, when the observation window becomes dirty, cleaning water or air may be sprayed on the distal end of the insertion portion, causing a temperature difference between the surface of the insertion portion distal end and the inside. For this reason, when moisture is contained in the insertion portion, condensation may occur in the objective optical system and the cover glass. Also, when using the stored electronic endoscope, the temperature of the electronic components such as the solid-state imaging device and the signal processing circuit immediately rises immediately after being connected to the processor device and turned on. On the other hand, the members such as the objective optical system and the cover glass gradually increase in temperature due to the heat of the electronic components. For this reason, immediately after turning on the power, there is a large temperature difference between the electronic component and a member such as an objective optical system or a cover glass, and condensation tends to occur.

  If dew condensation occurs on the inner surface of the objective optical system or the cover glass, the image quality may be remarkably deteriorated so that water droplets can be visually recognized in the image, making observation difficult.

  In order to prevent the above problems, in Patent Document 1, a heat radiating member having high thermal conductivity is provided in the vicinity (rear surface) of the solid-state imaging element or in the vicinity of the active element. The heat radiating member is fixed to the solid-state image sensor frame, and is connected to the objective lens frame via the extending portion. The driving heat generated from the solid-state imaging device or the like is radiated to the objective lens frame via the heat radiating member.

In Patent Document 2, a light shielding plate is provided at the exit end of the light guide, the illumination light is shielded by the light shielding plate, and the observation window is warmed by the light heat generated thereby.
JP 2002-291893 A JP-A-2005-319101

  In the invention described in Patent Document 1, since the solid-state imaging device, which is a heat source, the active device, and the objective lens frame are connected via a thermally conductive resin, a heat radiating member, and an extending portion, the distance is long. There was a problem that the utilization efficiency of heat was very bad. In addition, it takes time to warm the objective lens frame, and there is a problem that it cannot cope with a rapid temperature change.

  The invention described in Patent Document 2 is disadvantageous from the viewpoint of cost and space saving because it requires a mechanism such as a light shielding plate and an actuator for moving the light shielding plate. In addition, since the driving heat of the electronic component is not radiated, the problem of the performance deterioration of the electronic component due to the driving heat still remains.

  The present invention has been made in view of the above problems, and an object of the present invention is to efficiently and reliably prevent image quality deterioration of an endoscopic image due to driving heat of an electronic component.

  In order to achieve the above object, an imaging apparatus for an electronic endoscope of the present invention includes an objective optical system for capturing image light of an observation site in a subject, a lens barrel that holds the objective optical system, A solid-state image pickup device that picks up image light of a site to be observed and outputs an image pickup signal; a signal processing circuit of the solid-state image pickup device; and a heat radiating member having thermal conductivity. The signal processing circuit is disposed at a position facing the peripheral surface of the lens barrel. The heat radiating member connects the lens barrel and the signal processing circuit.

  The solid-state imaging device is attached to the barrel so that the surface of the light receiving portion is perpendicular to the optical axis of the objective optical system. The signal processing circuit is disposed at an angle of 90 ° with respect to the solid-state imaging device, and a surface facing the peripheral surface of the lens barrel is parallel to the optical axis of the objective optical system.

  It is preferable to provide a connection circuit board that electrically connects the solid-state imaging device and the signal processing circuit.

  The connection circuit board also serves as the heat dissipation member. In this case, the connection circuit board is based on a resin to which a thermally conductive filler is added.

  Moreover, it is preferable that the connection circuit board has a heat radiating portion that covers the entire surface of the signal processing circuit facing the peripheral surface of the lens barrel. In this case, the heat dissipation part is covered with a metal foil that forms a circuit pattern.

  It is preferable that the connection circuit board has a winding part that is wound and fixed so as to cover a peripheral surface of the lens barrel, which extends the heat dissipation part to the outside.

  The connection circuit board preferably includes a mounting portion on which the solid-state imaging device is flip-chip mounted via a protruding electrode.

  The connection circuit board is a flexible circuit board that is bent so that the signal processing circuit forms an angle of 90 ° with respect to the solid-state imaging device.

  In either one of the solid-state imaging device or the signal processing circuit, a groove for fitting and fixing the other is formed so as to form an angle of 90 ° with each other.

  The objective optical system includes a prism that is arranged so that an incident surface faces an output surface of the light receiving unit of the solid-state imaging device, and guides image light from the objective optical system to the light receiving unit. preferable. In this case, the signal processing circuit is disposed such that a rear end surface thereof is connected to a front end surface of the solid-state imaging device and a surface facing the peripheral surface of the lens barrel is parallel to the optical axis of the objective optical system. Is done.

  The heat dissipation member includes an adhesive for directly or indirectly bonding and fixing the lens barrel and the signal processing circuit. The adhesive is one to which a thermally conductive filler is added.

  The electronic endoscope of the present invention captures and captures an objective optical system for capturing image light of an observation site in a subject, a lens barrel that holds the objective optical system, and image light of the observation site. An imaging apparatus for an electronic endoscope having a solid-state imaging device that outputs a signal, a signal processing circuit of the solid-state imaging device, and a heat radiating member having thermal conductivity is provided. The signal processing circuit is disposed at a position facing the peripheral surface of the lens barrel. The heat radiating member connects the lens barrel and the signal processing circuit.

  According to the present invention, the signal processing circuit of the solid-state imaging device that is the main heat source is disposed at a position facing the peripheral surface of the lens barrel that holds the objective optical system, and the heat dissipation member that has thermal conductivity Since the signal processing circuit is connected, the driving heat of the signal processing circuit can be directly transferred to the lens barrel through the heat radiating member. Therefore, it is possible to efficiently and reliably prevent the image quality deterioration of the endoscopic image due to the driving heat of the electronic component.

[First embodiment]
In FIG. 1, the endoscope system 2 includes an electronic endoscope 10, a processor device 11, and a light source device 12. As is well known, the electronic endoscope 10 is connected to a flexible insertion portion 13 to be inserted into a body cavity of a patient and a distal end portion of the insertion portion 13, and an imaging device 40 (see FIGS. 3 and 4). Between the operation unit 15 and the connector 16, the connector 15 connected to the processor device 11 and the light source device 12, and the operation unit 15 connected to the light source device 12. And a universal cord 17.

  The operation unit 15 is provided with an angle knob 18 for bending the distal end portion 14 of the insertion portion 13 in the vertical and horizontal directions, an air supply / water supply button 19 for ejecting air and water from the distal end of the insertion portion 13, and the like. It has been. A forceps port 20 through which a treatment tool such as an electric knife is inserted is provided on the insertion portion 13 side of the operation portion 15.

  The processor device 11 is electrically connected to the light source device 12 and comprehensively controls the operation of the endoscope system 2. The processor device 11 supplies power to the electronic endoscope 10 via the universal cord 17 and the transmission cable 51 (see FIG. 3) inserted into the insertion portion 13, and drives the solid-state imaging device 38 (see FIG. 3). To control. Further, the processor device 11 receives the imaging signal output from the solid-state imaging device 38 via the transmission cable 51, and performs various processes on the received imaging signal to generate image data. The image data generated by the processor device 11 is displayed as an endoscopic image on a monitor 21 connected to the processor device 11 by a cable.

  2 and 3, an observation window 30, an illumination window 31, a forceps outlet 32, and an air / water supply nozzle 33 are provided on the end surface 14 a of the distal end portion 14. The observation window 30 is disposed at the center on one side of the end surface 14a. Two illumination windows 31 are arranged at symmetrical positions with respect to the observation window 30. Behind the illumination window 31, an exit end of a light guide 34 that guides illumination light from the light source device 12 is disposed. The illumination window 31 irradiates the observation site in the body cavity with the illumination light guided by the light guide 34.

  The forceps outlet 32 is connected to a forceps channel 35 disposed in the insertion portion 13 and communicates with the forceps port 20. The distal end of the treatment tool inserted through the forceps opening 20 is exposed from the forceps outlet 32. The air supply / water supply nozzle 33 injects air and water supplied from the air supply / water supply device built in the light source device 12 toward the observation window 30 according to the operation of the air supply / water supply button 19.

  In the back of the observation window 30, a lens barrel 37 is disposed that holds an objective optical system 36 for capturing image light of a site to be observed in the body cavity. The lens barrel 37 is attached so that the optical axis of the objective optical system 36 is parallel to the central axis of the distal end portion 14.

  A solid-state image sensor 38 is connected to the rear end of the lens barrel 37. The solid-state image sensor 38 is composed of, for example, a CCD image sensor or a CMOS image sensor. The solid-state imaging device 38 has a light receiving portion 39 provided on the front surface, a chip provided with an electrode pad on the back surface through a through electrode, or a so-called light receiving portion 39 provided on the back surface and a so-called electrode pad provided on the front surface. A back-illuminated chip that is repeatedly turned is used. The solid-state imaging device 38 is disposed such that the light receiving unit 39 faces the objective optical system 36 and the surface of the light receiving unit 39 is perpendicular to the optical axis of the objective optical system 36. The objective optical system 36, the lens barrel 37, the solid-state imaging device 38, and the like constitute an imaging device 40.

  As shown in FIG. 4 in which the periphery of the imaging device 40 is enlarged, a rectangular plate-like cover glass 42 is attached on the light receiving unit 39 via a square frame spacer 41 (see also FIG. 5). . The solid-state image sensor 38, the spacer 41, and the cover glass 42 are assembled by being bonded to each other with an adhesive. As a result, the light receiving unit 39 is accommodated in the sealed space surrounded by the spacer 41 and the cover glass 42, and the light receiving unit 39 is protected from intrusion of dust, water, and the like.

  A substantially S-shaped heat radiation / connection circuit board (hereinafter simply referred to as a board) 44 is flip-chip mounted on the back surface of the solid-state imaging element 38 via a plurality of protruding electrodes (bumps) 43.

  The substrate 44 is a heat conductive flexible circuit board based on a resin obtained by kneading a heat conductive filler such as silicon oxide, aluminum oxide, or magnesium oxide in a resin such as polyimide. The substrate 44 includes a mounting part 45 to which the solid-state imaging device 38 is connected, a heat radiating part 46 extending to the front end side of the front end part 14, and a transmission part 47 extending to the rear end side. The heat radiating part 46 and the transmission part 47 are bent at a right angle in the opposite direction to the mounting part 45. The heat dissipating part 46 protrudes to the vicinity of the lower center of the lens barrel 37.

  A signal processing circuit 49 is flip-chip mounted on the back surface of the heat radiating portion 46 via a plurality of protruding electrodes 48. Since the signal processing circuit 49 is attached to the back surface of the heat radiating portion 46 that protrudes to the vicinity of the lower center of the lens barrel 37, the signal processing circuit 49 is disposed at a position facing the peripheral surface of the lens barrel 37. The signal processing circuit 49 includes, for example, a circuit for transmitting a drive signal for driving the solid-state image sensor 38, a circuit for performing signal processing such as digitizing an image signal from the solid-state image sensor 38, and an image signal. A circuit or the like for transferring to the processor device is mounted.

  A plurality of electrode pads 50 are provided on the back surface of the transmission unit 47, and the transmission lines 52 drawn from the transmission cable 51 are soldered to the electrode pads 50. Note that the transmission cable 51 is a multi-core cable composed of a plurality of transmission lines 52, but only one transmission line 52 is shown in the figure to avoid complication.

  A circuit pattern 53 (see FIG. 6) that forms a connection circuit between the solid-state image sensor 38 and the signal processing circuit 49 is formed on the surface of the mounting portion 45 that faces the back surface of the solid-state image sensor 38. Similarly, a circuit such as a polyimide resin containing a heat conductive filler is sandwiched between the back surface of the heat radiating portion 46 facing the front surface of the signal processing circuit 49 and the back surface of the transmission portion 47 on which the electrode pads 50 are formed. A pattern 53 (not shown) is formed. The circuit pattern 53 is made of a metal foil such as a copper foil. The circuit pattern 53 on the front surface of the mounting portion 45 and the circuit pattern 53 on the back surface of the heat radiating portion 46 and the transmission portion 47 are connected by a through electrode (not shown).

  Among the metal foils that form the circuit pattern 53 on the front surface of the mounting unit 45 and the circuit pattern 53 on the back surface of the heat dissipating unit 46 and the transmission unit 47, some metal foils that do not contribute to transmission are the entire surface of the heat dissipating unit 46, The entire back surface of the heat radiating portion 46 other than the electrical connection portion with the signal processing circuit 49 is covered.

  A thermally conductive adhesive 54 is filled between the lower portion of the lens barrel 37, the lower surface of the solid-state imaging device 38, the spacer 41, and the cover glass 42, and the surface of the signal processing circuit 49 and the substrate 44. Are fixed to each other. Examples of the heat conductive adhesive 54 include an insulating heat conductive silicone adhesive (RTV rubber adhesive, etc.) and a one-part curable epoxy adhesive in which a heat conductive filler similar to the substrate 44 is kneaded. Used. In addition, the material of the board | substrate 44 and the heat conductive adhesive 54 mentioned here is an example, and a material other than the above may be used as long as it has heat conductivity.

  When manufacturing the imaging device 40, first, as shown in FIG. 5, a cover glass 42 is attached via a spacer 41 on the light receiving portion 39 of the solid-state imaging device 38.

  After the cover glass 42 is attached, as shown in FIG. 6, projecting electrodes 43 and 48 are formed on the mounting portions 45 of the substrate 44 and the electrode pads of the circuit pattern of the signal processing circuit 49, respectively, so that the solid-state imaging device 38 and the signal processing circuit are formed. 49, the mounting part 45, and the heat dissipation part 46 are flip-chip mounted. Thereafter, a thermally conductive adhesive 54 is poured as an underfill agent between the solid-state imaging device 38 and the signal processing circuit 49 and the substrate 44 to bond and fix each other. The protruding electrodes 43 and 48 may be formed on the electrode pads on the back surface of the solid-state imaging device 38 or the heat radiating portion 46.

  Next, the substrate 44 is bent into a substantially S shape. Then, the lens barrel 37 is attached to the cover glass 42 with an adhesive. Further, as shown in FIG. 7, a thermal conductive adhesive 54 is filled between the lower surface of the lens barrel 37, the solid-state imaging device 38, the spacer 41, and the lower surface of the cover glass 42 and the substrate 44, thereby fixing them to each other. To do. Finally, the transmission line 52 is connected to the electrode pad 50. In order to improve the wettability with respect to the heat conductive adhesive 54, a surface modification process such as a plasma process may be performed on a portion where the heat conductive adhesive 54 contacts, such as a lower part of the lens barrel 37.

  Next, the operation of the endoscope system 2 configured as described above will be described. When observing the inside of a patient's body cavity with the electronic endoscope 10, the practitioner connects the electronic endoscope 10 and the devices 11 and 12 and turns on the power of the devices 11 and 12. Then, information related to the patient is input to instruct to start the examination.

  After instructing the start of the examination, the practitioner inserts the insertion portion 13 into the body cavity and monitors the endoscopic image in the body cavity by the solid-state imaging device 38 while illuminating the body cavity with the illumination light from the light source device 12. Observe at 21.

  The imaging signal output from the solid-state imaging device 38 is subjected to various processing by the signal processing circuit 49 and then input to the processor device 11 via the transmission cable 51. In the processor device 11, various image processes are performed on the input imaging signal, and image data is generated. Thereby, the image data is displayed on the monitor 21 as an endoscopic image.

  When driven, the solid-state imaging device 38 and the signal processing circuit 49 emit driving heat due to an internal load or the like, and sometimes becomes 40 ° C. or higher and higher than the body temperature. On the other hand, the distal end portion 14 of the electronic endoscope 10 inserted into the body cavity has a temperature (˜37 ° C.) that is approximately the same as the body temperature.

  Immediately after the electronic endoscope 10 is turned on, the temperature of the solid-state imaging device 38 and the signal processing circuit 49 immediately rises, whereas members such as the objective optical system 36 and the cover glass 42 are connected to the solid-state imaging device 38 and the signal. The drive circuit heat is obtained and the temperature gradually rises. Further, when air or water is sprayed toward the observation window 30 by the air / water supply nozzle 33, the tip end portion 14 is rapidly cooled to about 30 ° C. For this reason, the approximate temperature distribution of the distal end portion 14 becomes higher in the order of the observation window 30, the objective optical system 36, the lens barrel 37, the cover glass 42, the spacer 41, the solid-state imaging device 38, and the signal processing circuit 49.

  Driving heat generated from the solid-state imaging device 38 and the signal processing circuit 49 is transmitted to the substrate 44 via the heat conductive adhesive 54. The heat transmitted to the substrate 44 is transmitted to the lens barrel 37 having a relatively low temperature mainly through the heat radiating portion 46 and the heat conductive adhesive 54. Part of the heat is radiated from the transmission unit 47 and the transmission cable 51 to the space on the rear end side of the front end portion 14. The heat transmitted to the lens barrel 37 warms not only the lens barrel 37 but also the internal objective optical system 36 and the observation window 30 at the tip.

  Due to the action of the substrate 44, the temperature difference between the observation window 30, the objective optical system 36, the lens barrel 37, which is a low-temperature part, and the cover glass 42, the spacer 41, the solid-state imaging device 38, and the signal processing circuit 49, which are high-temperature parts. The In other words, the low temperature part is warmed by driving heat, and the high temperature part is radiatively cooled, so that the temperature distribution of the tip part 14 becomes uniform.

  When the solid-state imaging device 38 and the signal processing circuit 49 become high temperature, these performances are lowered and the image quality of the endoscopic image is deteriorated. Further, if the temperature difference between the members of the distal end portion 14 is large, condensation occurs on the inner surfaces of the observation window 30 and the cover glass 42. In this example, the heat of the solid-state imaging device 38 and the signal processing circuit 49 is dissipated by the substrate 44 and the heat conductive adhesive 54, and the temperature distribution of the distal end portion 14 becomes uniform. The performance of the processing circuit 49 does not deteriorate, and no condensation occurs. Therefore, there is no problem that the performance of the solid-state imaging device 38 or the signal processing circuit 49 is deteriorated or the image quality of the endoscope image is deteriorated due to dew condensation and observation becomes difficult.

  Since the signal processing circuit 49 that is a heat source is disposed below the lens barrel 37, the driving heat of the signal processing circuit 49 is directly transmitted to the lens barrel 37. For this reason, thermal efficiency is better than when the signal processing circuit 49 is moved away from the lens barrel 37, and it does not take time to warm the lens barrel 37. It corresponds to a case where a temperature difference occurs immediately after the electronic endoscope 10 is turned on, or a case where a sudden temperature change occurs by injecting air or water toward the observation window 30 with the air / water supply nozzle 33. be able to.

  As the name implies, the substrate 44 serves both as a connection between the solid-state imaging device 38 and the signal processing circuit 49 and a function of heat dissipation, thereby contributing to the reduction of components, manufacturing costs, and space saving.

  The length of the tip portion 14 can be shortened by the amount that the signal processing circuit 49 is pushed toward the lens barrel 37 side. Since the distal end portion 14 is made of a hard material, if the distal end portion 14 is long, it causes pain when the patient swallows, but this pain can be relieved. Further, since the connection between the solid-state imaging device 38, the substrate 44, and the signal processing circuit 49 is further reinforced by the heat conductive adhesive 54, the mechanical strength can be increased.

  In 1st embodiment, although the board | substrate 44 which has the mounting part 45, the thermal radiation part 46, and the transmission part 47 is used, this invention is not limited to this. In addition, below, only the code | symbol is attached | subjected about the member same as 1st embodiment, and description is abbreviate | omitted.

[Second Embodiment]
In FIG. 8 showing the imaging device 60 of the second embodiment, the substrate 61 is a straight shape having no bent portions, unlike the substrate 44 of the first embodiment. The substrate 61 has the same heat radiation part 62 and transmission part 63 as the substrate 44, but does not have a mounting part. The function corresponding to the mounting portion is performed by the flexible circuit board 64. Similar to the mounting portion 45 of the first embodiment, the solid-state imaging device 38 is flip-chip mounted on the flexible circuit board 64. In addition, the flexible circuit board 64 is connected to the substrate 61 via the protruding electrode 65 in the vicinity of the boundary between the heat radiation part 62 and the transmission part 63.

  When manufacturing the imaging device 60, the solid-state imaging device 38 is flip-chip mounted on the flexible circuit board 64 after performing the process of FIG. 5 as in the first embodiment. The flexible circuit board 64 is flip-chip mounted on the substrate 61 before or after the signal processing circuit 49 is flip-chip mounted on the substrate 61.

  Thereafter, similarly to the first embodiment, the lens barrel 37 is attached to the cover glass 42 with an adhesive, and the lower surface of the lens barrel 37, the solid-state imaging device 38, the spacer 41, and the lower surface of the cover glass 42 and the substrate 61. Then, the heat conductive adhesive 54 is filled to fix the two together, and finally, the transmission line 52 is connected to the electrode pad 50. According to this embodiment, the process of bending the heat dissipation / connection circuit board can be omitted. For this reason, the board | substrate 61 does not need to be a flexible circuit board.

[Third embodiment]
In FIG. 9, an imaging device 70 of the third embodiment connects a solid-state imaging device 71 and a signal processing circuit 72 with a short board (which may be a flexible cable) 73 without a mounting part, a heat dissipation part, and a transmission part, Furthermore, the point which directly adheres and fixes the signal processing circuit 72 to the lens barrel 37 with the heat conductive adhesive 54 is different from the first and second embodiments.

  The solid-state image sensor 71 has both a light receiving portion 74 and an electrode pad provided on the surface. The signal processing circuit 72 is provided with an electrode pad 75 connected to the transmission line 52 on the back surface, and this electrode pad 75 is an electrode pad of a circuit pattern on the surface of the signal processing circuit 72 and a through electrode (both not shown). Connected with. The substrate 73 connects the electrode pad of the solid-state image sensor 71 and the electrode pad of the signal processing circuit 72 via the protruding electrodes 76 and 77. The thermally conductive adhesive 54 is filled between the lower portion of the lens barrel 37 and the signal processing circuit 72.

  When manufacturing the imaging device 70, after performing the process of FIG. 5 as in the first and second embodiments, the protruding electrode 76, the electrode pad of the solid-state imaging device 71 and the electrode pad of the signal processing circuit 72, The substrate 73 is flip-chip mounted via 77. Then, the solid-state imaging device 71 and the signal processing circuit 72 are bent 90 ° with the substrate 73 as an axis. The subsequent steps are the same as those in the first and second embodiments.

  As modified examples of the present embodiment, FIG. 10 and FIG. 11 can be cited. In the example shown in FIG. 10, the solid-state imaging element 79 provided with electrode pads not only on the surface but also on the side surface facing the signal processing circuit 78 is used. The electrode pad on the side surface of the solid-state image sensor 79 is flip-chip mounted via the electrode pad of the signal processing circuit 78 and the protruding electrode 80. The electrode pads on the surface of the solid-state imaging device 79 and the electrode pads of the signal processing circuit 78 are connected to the substrate 73 via the protruding electrodes 76 and 77, as in the imaging device 70 of FIG.

  In the example shown in FIG. 11, the same solid-state imaging element 71 as that in FIG. 9 is used, and the signal processing circuit 81 is provided with a groove 82 for fitting the side surface portion of the solid-state imaging element 71. The groove 82 is formed by a known dicing or etching technique. In this case, first, the side surface portion of the solid-state image sensor 71 is fitted into the groove 82 and bonded and fixed with the heat conductive adhesive 54, and then the electrode pad on the surface of the solid-state image sensor 71 and the electrode pad of the signal processing circuit 81 are connected. Connect with solder 83. In contrast to this example, a groove in which the rear end portion of the signal processing circuit is fitted in the solid-state imaging device may be formed.

  In the example shown in FIG. 9, since the substrate 73 is just like a hinge, stress is applied to the substrate 73 when it is bent many times during the manufacturing of the imaging device 70. On the other hand, in the example shown in FIGS. 10 and 11, since the solid-state imaging device and the signal processing circuit are fixed first in a state of forming an angle of 90 °, it is not necessary to consider the stress due to bending.

  According to this embodiment, the scale of the heat dissipation / connection circuit board can be reduced, or the heat dissipation / connection circuit board can be omitted, which can contribute to a reduction in component costs. In the examples shown in FIGS. 9 and 10, the substrate 73 has only a heat conduction function between the solid-state imaging device and the signal processing circuit, and the heat conduction to the lens barrel 37 is mainly performed by the heat conductive adhesive 54. The substrate 73 may be a simple flexible circuit board having no heat dissipation function. In addition, the main point of this embodiment is that the signal processing circuit is bent at 90 ° with respect to the solid-state imaging device, and the signal processing circuit is arranged at the lower part of the lens barrel. Therefore, it is not necessary to connect the solid-state imaging device and the signal processing circuit, and the solid-state imaging device and the signal processing circuit may be connected by the solder 83 illustrated in FIG.

[Fourth embodiment]
12 and 13, the substrate 91 used in the imaging device 90 of the present embodiment has a winding portion 92 in which the metal foil on the heat radiation portion 46 of the substrate 44 of the first embodiment is widened in the width direction. . The winding portion 92 is wound around the lens barrel 37 so as to cover the peripheral surface of the lens barrel 37, and is bonded and fixed to the lens barrel 37 via a heat conductive adhesive 54.

  According to the present embodiment, the driving heat of the solid-state imaging device 38 and the signal processing circuit 49 is reduced as compared with the other embodiments in which only the lower surface of the lens barrel 37 is filled with the heat conductive adhesive 54. The entire circumference can be spread evenly. Therefore, thermal efficiency can be further increased. The winding portion 92 is not limited to the one in which the metal foil is spread left and right as in this example, but may be one in which the metal foil is extended in one direction or one in which the heat radiating portion 46 itself is widened.

  In each of the above embodiments, an example is given in which the solid-state imaging device is arranged so that the surface of the light receiving unit is perpendicular to the optical axis of the objective optical system, but the present invention is not limited to this.

[Fifth embodiment]
In FIG. 14, the imaging apparatus 100 of the present embodiment uses the solid-state imaging device 71 and the signal processing circuit 72 of FIG. 9, and a prism 101 is provided between the lens barrel 37 and the cover glass 42. The prism 101 has an incident surface 101 a connected to the lens barrel 37 and an output surface 101 b connected to the cover glass 42. Thereby, the optical axis of the objective optical system 36 and the surface of the light receiving unit 74 of the solid-state imaging device 71 are arranged in parallel.

  The solid-state imaging device 71 and the signal processing circuit 72 are bonded such that the front end surface and the rear end surface are in contact with each other. The signal processing circuit 72 is disposed below the lens barrel 37 by being adhered to the front end surface of the solid-state image sensor 71. The lower part of the signal processing circuit 72 and the lens barrel 37 is filled with a heat conductive adhesive 54.

  Electrode pads are formed on the surface of the front end of the solid-state image sensor 71 and the rear end of the signal processing circuit 72, and these are electrically connected by bonding wires or the like. The present invention can also be applied to the imaging device 100 using a bending optical system such as the prism 101.

  As described above, various aspects of the present invention have been described with reference to the first to fifth embodiments. In short, the signal processing circuit as a heat source is arranged at a position facing the peripheral surface of the lens barrel, and the signal processing circuit and Any change can be made without departing from the gist of the present invention in which the lens barrel is connected by a heat conductive member.

  In addition, you may employ | adopt the aspect shown in FIG. 15, FIG. The imaging device 110 shown in FIG. 15 has the same connection form between the solid-state imaging device 71 and the signal processing circuit 72 as in the example of FIG. 14, omits the prism 101, and is similar to the first to fourth embodiments. The solid-state image sensor 71 is arranged so that the surface is perpendicular to the optical axis of the objective optical system 36. The signal processing circuit 72, the spacer 41, the lower surface of the cover glass 42, and the lower part of the lens barrel 37 are connected by a heat conductive heat sink 111 bent by 90 ° and a heat conductive adhesive 54. . The heat sink 111 is made of the same material as the base of the substrate 44.

  In the imaging device 120 illustrated in FIG. 16, the signal processing circuit 121 is flip-chip mounted on the back surface of the solid-state imaging device 38 via the protruding electrode 43. Then, the lower surface of the signal processing circuit 121 and the lower part of the solid-state imaging device 38, the spacer 41, the cover glass 42, and the lens barrel 37 are formed with the heat radiating plate 122 and the heat conductive adhesive 54 made of the same material as the heat radiating plate 111. Connected. Reference numeral 123 denotes an electrode pad to which the transmission line 52 is soldered. Since the signal processing circuit 121 is flip-chip mounted on the back surface of the solid-state imaging device 38, the size of the distal end portion 14 in the radial direction can be reduced as compared with the example of FIG. In the examples shown in FIGS. 15 and 16, the signal processing circuit and the lens barrel are separated from each other, so that the thermal efficiency is slightly inferior to the above embodiments.

  As the heat sinks 111 and 122, a metal having good thermal conductivity such as copper or aluminum may be used. When metal is used, the connection between the solid-state imaging device and the signal processing circuit can be reinforced. In the example shown in FIG. 16, since the heat sink is arranged between the solid-state imaging device or signal processing circuit and the forceps channel, the influence of electromagnetic noise due to a high-frequency electric knife or the like inserted through the forceps channel is blocked. Can do.

  In each of the above embodiments, the heat conductive adhesive is filled on the entire surface of each member, but may be locally filled as long as the heat conductivity is sufficient.

  In each of the above embodiments, the electronic endoscope is described as an example. However, the present invention can be applied to an ultrasonic endoscope in which an ultrasonic transducer is built in addition to the imaging apparatus. . Further, the present invention can be applied not only to medical electronic endoscopes but also to electronic endoscopes used in the industrial field.

It is a block diagram of an endoscope system. It is a figure which shows the end surface of the front-end | tip part of an electronic endoscope. It is sectional drawing which shows the internal structure of the front-end | tip part of an electronic endoscope. It is sectional drawing to which the periphery of the imaging device of 1st embodiment was expanded. It is explanatory drawing of the process of attaching a cover glass to a solid-state image sensor through a spacer. It is explanatory drawing of the process of flip-chip mounting a solid-state image sensor and a signal processing circuit on a heat dissipation and connection circuit board. It is explanatory drawing of the process of bend | folding a heat dissipation and connection circuit board, and adhere-fixing to a lens-barrel etc. via a heat conductive adhesive agent. It is sectional drawing which shows the imaging device of 2nd embodiment. It is sectional drawing which shows the imaging device of 3rd embodiment. It is a figure which shows the modification of 3rd embodiment. It is a figure which shows the modification of 3rd embodiment. It is a perspective view which shows the thermal radiation and connection circuit board used for the imaging device of 4th embodiment. It is a perspective view which shows the imaging device of 4th embodiment. It is sectional drawing which shows the imaging device of 5th embodiment. It is sectional drawing which shows the other example of an imaging device. It is sectional drawing which shows the further another example of an imaging device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Endoscope system 10 Electronic endoscope 36 Objective optical system 37 Lens barrel 38, 71, 79 Solid-state image sensor 39, 74 Light-receiving part 40, 60, 70, 90, 100, 110, 120 Imaging device 43, 76 Projection electrode 44, 61, 73, 91 Heat dissipation and connection circuit board (board)
45 mounting part 46, 62 heat radiation part 49, 72, 78, 81, 121 signal processing circuit 53 circuit pattern 54 heat conductive adhesive 64 flexible circuit board 82 groove 92 winding part 101 prism 111, 122 heat radiation plate

Claims (15)

An objective optical system for capturing image light of an observation site in the subject;
A lens barrel holding the objective optical system;
A solid-state imaging device that captures image light of an observed site and outputs an imaging signal;
A signal processing circuit of the solid-state imaging device disposed at a position facing the peripheral surface of the lens barrel;
An imaging apparatus for an electronic endoscope, comprising: a heat-dissipating member having thermal conductivity for connecting the lens barrel and the signal processing circuit. The solid-state imaging device is attached to the barrel so that the surface of the light receiving portion is perpendicular to the optical axis of the objective optical system,
The signal processing circuit is disposed at an angle of 90 ° with respect to the solid-state imaging device, and a surface facing the peripheral surface of the lens barrel is parallel to the optical axis of the objective optical system. The imaging device for an electronic endoscope according to claim 1.   The imaging apparatus for an electronic endoscope according to claim 1, further comprising a connection circuit board that electrically connects the solid-state imaging device and the signal processing circuit.   The imaging device for an electronic endoscope according to claim 3, wherein the connection circuit board also serves as the heat dissipation member.   The imaging device for an electronic endoscope according to claim 4, wherein the connection circuit board is based on a resin to which a thermally conductive filler is added.   6. The electronic endoscope imaging apparatus according to claim 4, wherein the connection circuit board includes a heat radiating portion that covers the entire surface of the signal processing circuit facing the peripheral surface of the lens barrel.   The imaging device for an electronic endoscope according to claim 6, wherein the heat radiating portion is covered with a metal foil that forms a circuit pattern.   The electronic circuit according to claim 6, wherein the connection circuit board includes a winding part that is wound and fixed so as to cover a peripheral surface of the lens barrel, the outside extending the heat radiating part. Imaging device for endoscope.   9. The electronic endoscope imaging apparatus according to claim 3, wherein the connection circuit board has a mounting portion on which the solid-state imaging device is flip-chip mounted via a protruding electrode.   10. The electronic circuit according to claim 3, wherein the connection circuit board is a flexible circuit board that is bent so that the signal processing circuit forms an angle of 90 degrees with respect to the solid-state imaging device. Endoscopic imaging device.   3. The electron according to claim 2, wherein either one of the solid-state imaging device or the signal processing circuit is formed with a groove for fitting and fixing the other so as to form an angle of 90 ° with each other. Endoscopic imaging device. An incident surface on the objective optical system, and a prism that guides image light from the objective optical system to the light receiving unit, the light emitting unit being disposed so that the exit surface faces the surface of the light receiving unit of the solid-state imaging device,
The signal processing circuit is disposed such that a rear end surface thereof is connected to a front end surface of the solid-state imaging device and a surface facing the peripheral surface of the lens barrel is parallel to the optical axis of the objective optical system. The imaging device for an electronic endoscope according to claim 1.   13. The electronic endoscope according to claim 1, wherein the heat radiating member includes an adhesive for directly or indirectly bonding and fixing the lens barrel and the signal processing circuit. Mirror imaging device.   The imaging apparatus for an electronic endoscope according to claim 13, wherein the adhesive is one to which a heat conductive filler is added. An objective optical system for capturing image light of an observation site in the subject;
A lens barrel holding the objective optical system;
A solid-state imaging device that captures image light of an observed site and outputs an imaging signal;
A signal processing circuit of the solid-state imaging device disposed at a position facing the peripheral surface of the lens barrel;
An electronic endoscope comprising: an electronic endoscope imaging device having a thermal conductive heat radiating member that connects the lens barrel and the signal processing circuit.

Images