JP2012217605A - Camera module for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a miniaturized camera module for an endoscope to be mounted on the distal end of an insertion portion of an endoscope.SOLUTION: The camera module 30 includes an objective optical system 32, and a lens moving mechanism 36. The objective optical system 32 includes a second lens 40 lens and a prism 44. The second lens 40, which is a movable lens for magnification, is moved by the lens moving mechanism 36 having a motor 50. The prism 44 has a reflection surface 44b inclined at an angle of 45° to an optical axis of the second lens 40. The motor 50 is disposed behind the prism 44 with a drive shaft 56 in parallel to the longitudinal direction of an insertion portion 13.

Description

  The present invention relates to an endoscope camera module mounted at a distal end portion of an insertion portion of an endoscope.

  In the endoscope, a camera module is built in a distal end portion of an insertion portion that is inserted into the inspection hole. The camera module is a unit in which a movable lens, a lens moving mechanism that moves the movable lens, a circuit board having an image sensor and a drive circuit that drives the image sensor, and the like are imaged. The camera module is connected to a monitor outside the inspection hole, and an image photographed by the camera module is displayed on this monitor.

  The camera module is required to be small in order to ease the burden on the patient. However, if the circuit board is arranged perpendicular to the optical axis of the photographing lens, there is a problem that the width of the camera module becomes wide. For this reason, in Patent Document 1 below, the circuit board is disposed substantially parallel to the optical axis of the photographing lens, and the subject light is bent by the prism disposed behind the photographing lens and is incident on the image sensor on the circuit board. (See Patent Document 1 below).

  In Patent Document 1 below, a movable lens that is moved to change the photographing magnification and a motor that moves the movable lens are provided, and the movable lens is movable by rotating a rotating shaft directly connected to the drive shaft of the motor. The lens is moved. Furthermore, in Patent Document 1 below, a cut is made in the cylindrical surface of the first ring on the tip end side of the angle ring on the tip end side of the insertion portion, and the cut portion is deformed to support the motor.

JP2000-121957A

  Although the apparatus described in Patent Document 1 can prevent the problem that the width of the insertion portion is widened due to the influence of the image sensor, the structure is such that the drive shaft of the motor is directly connected to the rotation shaft. A dead space that is not arranged is generated, which hinders a reduction in diameter. In addition, there is a problem that the length of the photographic lens in the optical axis direction (longitudinal direction of the insertion portion) is increased by directly connecting the motor drive shaft to the rotation shaft.

  The present invention has been made in view of the above problems, and aims to reduce the size of an endoscope camera module.

  In order to achieve the above object, an endoscope camera module according to the present invention includes an imaging lens having a movable lens movable in an optical axis direction, and subject light incident from the imaging lens is substantially the same as the optical axis direction. A prism that reflects in a perpendicular direction, a circuit board that has an imaging element that photoelectrically converts an optical image formed through the photographing lens and the prism, and a side that is long in the optical axis direction and that is lateral to the photographing lens. A lens moving mechanism that moves the movable lens in the direction of the optical axis by rotation of the rotating shaft, and a rotatable driving shaft, and receives the supply of electric power from the outside. A motor that rotates the drive shaft, and a rotational force transmission mechanism that transmits the rotational force of the drive shaft to the rotary shaft, and the motor is in a state where the drive shaft is parallel to the optical axis direction. It is characterized in that arranged behind the prism.

  The rotating shaft includes a plurality of rotating bodies, and each rotating body is arranged in the optical axis direction from the back side where the drive shaft is provided toward the front side where the movable lens is provided, and is a common axis. The shafts adjacent to each other rotate so as to rotate around and have a predetermined amount of rotational play, and the rotational force of the drive shaft is sequentially transmitted from the rotating body on the back side to the rotating body on the front side. It may be a thing.

  At least three of the rotating bodies may be provided, and the rotational play angles set between adjacent rotating bodies may be different from each other.

  The angle of the rotational play may be set larger as it goes from the back side to the front side.

  As the rotator, two types of rotators, a rod-shaped rotator and a cylindrical rotator, are used alternately, and the rod-shaped rotator is disposed along the outer periphery of the end on the tubular rotator side. The cylindrical rotating body includes outer circumferential protrusions arranged at intervals, and the cylindrical rotating body has an inner diameter larger than the outer periphery of the rod-shaped rotating body including the outer circumferential protrusion, and is disposed so as to surround the rod-shaped rotating body together with the outer circumferential protrusion. In addition, the inner peripheral protrusion inserted into the movement path of the outer peripheral protrusion is erected on the inner wall, and the inner peripheral protrusion is pressed by the outer peripheral protrusion to rotate integrally with the rod-shaped rotating body. Good.

  The lens moving mechanism reverses the motor or repeats the reverse and normal rotation of the motor within a range in which the lens is not moved after the lens is moved, and the drive shaft is rotated in any direction. Alternatively, the motor may be stopped after moving each rotating body to a neutral position where the amount of rotation from the start of rotation until all the rotating bodies rotate together is substantially the same.

  A main body case that holds the photographing lens, the lens moving mechanism, and the rotation shaft, and holds the motor and the rotational force transmission mechanism, and is fixed to the back side of the main body case and integrated with the main body case. A motor case may be provided.

  The lens moving mechanism, the rotating shaft, the rotational force transmitting mechanism, and the driving shaft may be covered with at least one of the main body case and the motor case, and may be shielded from the outside.

  The motor may be bonded to the motor case with an adhesive having thermal conductivity.

  It has a cylinder body which is arranged so as to surround the rotation axis and whose rotation around the rotation axis is restricted, and the lens moving mechanism moves the cylinder body along the longitudinal direction of the rotation axis, thereby While moving the movable lens, the cylindrical body has a spiral shape that engages with a spiral cam groove formed on the outer periphery of the rotating shaft, or a protrusion that engages with a protrusion formed on the outer periphery of the rotating shaft. The cam groove may be provided on the inner wall, and may slide in the longitudinal direction of the rotary shaft as the rotary shaft rotates.

  It has a cylinder body which is arranged so as to surround the rotation axis and whose rotation around the rotation axis is restricted, and the lens moving mechanism moves the cylinder body along the longitudinal direction of the rotation axis, thereby While moving the movable lens, the cylindrical body has a helical thread that engages with a helical screw groove formed on the outer periphery of the rotating shaft, or a helical screw formed on the outer periphery of the rotating shaft. A spiral thread groove that engages with the screw thread may be provided on the inner wall, and may slide in the longitudinal direction of the rotation shaft as the rotation shaft rotates.

  According to the present invention, since the motor for moving the movable lens is disposed behind the prism, the camera module can be reduced in size by effectively using the space behind the prism.

It is an external view which shows the structure of an electronic endoscope system. It is a top view showing the end face of the tip part of an electronic endoscope. It is a top view of a camera module, (A) is a front view, (B) is a rear view. It is sectional drawing which observed the camera module from the side. It is an exploded view of a rotating shaft. It is explanatory drawing which shows a mode that the rotational force of a 1st rod-shaped rotary body is transmitted to a 1st cylindrical rotary body. It is explanatory drawing which shows a mode that the rotational force of a 2nd rod-shaped rotary body is transmitted to a 2nd cylindrical rotary body. It is a flowchart which shows the flow of operation | movement of an electronic endoscope. It is a front view of a camera module.

  As shown in FIG. 1, the electronic endoscope system 2 includes an electronic endoscope 10, a processor device 11, and a monitor 12. The electronic endoscope 10 includes a flexible insertion portion 13 that is inserted into the inspection hole, an operation portion 14 that is connected to the proximal end portion of the insertion portion 13, and a universal cord 16 that is connected to the processor device 11. And have.

  Air and water are ejected from the angle knob for curving the insertion part 13 so that the front-end | tip part 17 of the insertion part 13 faces up and down, right and left, and the air supply / water supply nozzle 20 (refer FIG. 2). In addition to the air / water supply button, operation members such as a release button for recording the observation image as a still image and a magnification button 21 for changing the magnification of the observation image are provided. Further, a forceps port through which a treatment tool such as an electric knife is inserted is provided on the distal end side of the operation unit 14. The forceps opening communicates with a forceps outlet 22 (see FIG. 2) provided at the distal end portion 17 through a forceps channel in the insertion portion 13.

  The processor device 11 supplies power to the camera module 30 (see FIGS. 2 to 4) mounted on the distal end portion 17 via the universal cord 16 and the transmission cable 68 (see FIG. 4) inserted into the insertion portion 13. Drive control is performed. Further, the processor device 11 receives the imaging signal output from the camera module 30 via the transmission cable 68, and performs various processes on the received imaging signal to generate image data. Then, the generated image data is displayed as an observation image on the monitor 12 connected to the processor device 11 with a cable.

  As shown in FIG. 2, the end surface 17 a of the distal end portion 17 is provided with an air supply / water supply nozzle 20, a forceps outlet 22, an illumination window 24 through which illumination light is emitted, and an observation window 26. The observation window 26 includes an opening formed in the end surface 17a, and a camera module 30 is disposed behind the observation window 26. A first lens 38 constituting the objective optical system 32 (see FIG. 4) of the camera module 30 is fitted in the observation window 26.

  As shown in FIGS. 3A, 3 </ b> B, and 4, the camera module 30 includes an objective optical system 32, a circuit board 34, and a lens moving mechanism 36. The objective optical system 32 includes a photographic lens and a prism 44. The photographing lens includes first, second, and third lenses 38, 40, and 42, which are arranged side by side along an optical axis parallel to the longitudinal direction of the insertion portion 13.

  The first and third lenses 38 and 42 are fixed lenses. The first lens 38 has a front end fitted into the observation window 26 and a rear end fitted into the front end of the cylindrical barrel 46 and fixed. The third lens 42 is fixed to the rear end portion of the lens barrel 46. On the other hand, the second lens 40 is a variable power lens (movable lens) for changing the photographing magnification. The second lens 40 is slidably supported by the lens barrel 46 and is moved by the lens moving mechanism 36.

  The prism 44 includes an incident surface 44a, a reflecting surface 44b, and an exit surface 44c. The outer edge portion of the incident surface 44a is bonded and fixed to the rear end of the lens barrel 46. Subject light is incident on the incident surface 44 a via the first to third lenses 38 to 42. The reflecting surface 44b is inclined 45 ° with respect to the incident surface 44a, and refracts the optical path of the subject light incident from the incident surface 44a by 90 °. The exit surface 44c is inclined by 90 ° with respect to the entrance surface 44a, and emits subject light reflected by the reflection surface 44b.

  The circuit board 34 is electrically connected to the processor device 11 via a transmission cable 68. The circuit board 34 is provided with a CCD 35 and a drive circuit for driving the CCD 35. The CCD 35 includes an imaging surface 35 a on which a plurality of photoelectric conversion elements are arranged, and the circuit board 34 is bonded and fixed to the emission surface 44 c with the imaging surface 35 a facing the emission surface 44 c of the prism 44. The The CCD 35 photoelectrically converts subject light emitted from the emission surface 44c and incident on the imaging surface 35a to generate an imaging signal. In this manner, the tip portion 17 can be reduced in diameter by arranging the circuit board 34 so that the imaging surface 35 a is parallel to the longitudinal direction of the insertion portion 13.

  The lens moving mechanism 36 includes a motor 50, a rotational force transmission mechanism 52, and a rotating shaft 54. As the motor 50, for example, a DC motor is used. The motor 50 includes a main body 58 having a drive shaft 56 and drive cables 60 and 62 provided on the back surface of the main body 58, and the drive shaft 56 is oriented in a direction corresponding to the direction of the current passed through the drive cables 60 and 62. Rotate. The drive cables 60 and 62 are connected to the transmission cable 68 via a sub circuit board 66 fixed to the upper surface of the circuit board 34.

  The motor 50 is disposed behind the prism 44 and is attached to and supported by a left and right split motor case 70 with the drive shaft 56 parallel to the longitudinal direction of the insertion portion 13. A cylindrical holder 72 surrounding the outer periphery of the main body 58 is provided at the rear end of the motor case 70. The holder 72 is made of a material having high heat dissipation such as aluminum, and the motor 50 is bonded to the inner periphery of the holder 72 with an adhesive 74 having high thermal conductivity.

  Thus, by arranging the motor 50 behind the prism, the space behind the prism can be effectively utilized, and the camera module 30 can be downsized. Furthermore, by arranging the motor 50 behind the prism, for example, the diameter of the camera module can be increased without increasing the size of the camera module as compared with the case where the motor is arranged so that the drive shaft is directly connected to the rotation shaft described later. A motor, that is, a motor having a large rotational torque can be mounted. Further, since the motor 50 is attached to the holder 72 with high heat dissipation by the adhesive 74 having high thermal conductivity, heat can be efficiently exhausted from the motor 50 and heat generation of the motor 50 can be suppressed.

  The rotational force transmission mechanism 52 includes first, second, and third gears 76, 78, and 80. The first to third gears 76 to 80 are arranged in the motor case 70 and are provided to be rotatable around an axis parallel to the drive shaft 56. The first gear 76 is fixed to the tip of the drive shaft 56 and rotates integrally with the drive shaft 56. The second gear 78 meshes with the first gear 76 and rotates as the first gear 76 rotates. Further, the second gear 78 is meshed with the third gear 80, and the third gear 80 rotates as the second gear 78 rotates. The first to third gears 76 to 80 are covered with the motor case 70 and are cut off from the outside of the motor case 70 so that dust, dust, and the like generated with the rotation are not scattered outside.

  A rotating shaft 54 is connected to the tip of the third gear 80. The rotating shaft 54 is housed in a cylindrical main body case 82 and is disposed on the side of the objective optical system 32. The rotary shaft 54 is rotatably supported by the main body case 82 and is covered with the main body case 82 to be shielded from the outside so that dust, dust, and the like generated by the rotation are not scattered outside. .

  The rotating shaft 54 includes a first rod-shaped rotating body 84, a first cylindrical rotating body 86, a second rod-shaped rotating body 88, a second cylindrical rotating body 90, and a third rod-shaped rotating body 92, which are the third gear 80. To the end face 17a in this order. These are all provided so as to be rotatable around a common axis parallel to the drive shaft.

  As shown in FIG. 5, the first rod-like rotating body 84 is fixed at the rear end of the third gear 80 and rotates integrally with the third gear 80. The first rod-shaped rotating body 84 is formed with a locking ring 84a and a protrusion 84b. The locking ring 84 a is provided at the center in the longitudinal direction of the first rod-shaped rotating body 84. As for the 1st rod-shaped rotary body 84, this latching ring 84a is pinched | interposed between the rear wall of the main body case 82, and the 1st cylindrical rotary body 86, and the movement to the front and back is controlled (refer FIG. 4). . Four protrusions 84b are provided at 90 ° rotation position intervals along the outer periphery of the distal end portion of the first rod-shaped rotating body 84 (see FIG. 6).

  The first cylindrical rotating body 86 is formed to be slightly larger than the front end portion of the first rod-shaped rotating body 84 and is provided so as to cover the front end portion of the first rod-shaped rotating body 84 at the rear end portion. A protrusion 86 a is provided on the inner periphery of the first cylindrical rotating body 86. Four protrusions 86a are provided along the inner periphery of the first cylindrical rotating body 86 at intervals of a rotation position of 90 °, and each of these protrusions 86a is inserted into the movement path of the protrusion 84b of the first rod-shaped rotating body 84. (See FIG. 6).

  The rear end portion of the second rod-shaped rotating body 88 is disposed inside the front end portion of the first cylindrical rotating body 86. At the rear end of the second rod-shaped rotating body 88, four protrusions 88a are provided along the outer periphery at a rotation position interval of 90 °, and each protrusion 88a moves the protrusion 86a of the first cylindrical rotating body 86. It is inserted in the path (see FIG. 6). In addition, a locking ring 88b for restricting the movement of the second rod-shaped rotating body 88 in the front-rear direction is provided at the center in the longitudinal direction of the second rod-shaped rotating body 88. Furthermore, two protrusions 88c are provided at the distal end portion of the second rod-shaped rotating body 88 at a rotation position interval of 180 ° along the outer periphery (see FIG. 7).

  The 2nd cylindrical rotary body 90 is provided so that the front-end | tip part of the 2nd rod-shaped rotary body 88 may be covered by a rear-end part. The second cylindrical rotator 90 is provided with two protrusions 90a at intervals of 180 ° rotation position along the inner periphery, and these protrusions 90a are on the movement path of the protrusion 88c of the second rod-shaped rotator 88. Has been inserted (see FIG. 7).

  The rear end portion of the third rod-shaped rotating body 92 is disposed inside the front end portion of the second cylindrical rotating body 90. Two protrusions 92a are provided at the rear end of the third rod-shaped rotating body 92 at a rotation position interval of 180 ° along the outer periphery, and each protrusion 92a moves the protrusion 90a of the second cylindrical rotating body 90. It is inserted in the path (see FIG. 7). Further, the third rod-shaped rotating body 92 is provided with a locking ring 92b for describing the movement of the third rod-shaped rotating body 92 in the front-rear direction in front of the protrusion 92a. Further, a spiral cam groove 92c is formed in the third rod-shaped rotating body 92 along the outer periphery on the front end side of the locking ring 92b.

  The front end side of the third rod-shaped rotating body 92 is inserted into the cylindrical body 94. The cylindrical body 94 is formed with a protrusion 94 a that engages with the cam groove 92 c of the third rod-shaped rotating body 92 on the inner periphery. Further, the cylindrical body 94 is integrated with the second lens 40 via the arm 96, and the rotation around the third rod-shaped rotating body 92 is restricted.

  Hereinafter, operations of the rotational force transmission mechanism 52 and the rotating shaft 54 until the rotational force of the motor 50 is transmitted to the second lens and the second lens moves will be described. When the motor 50 rotates, this rotational force is transmitted to the first rod-shaped rotating body 84 via the first to third gears 76-80, and the first rod-shaped rotating body 84 rotates.

  As shown in FIG. 6A, the first rod-shaped rotating body 84 has a neutral position in which the protrusion 84b is positioned in the middle of the protrusion 86a of the first cylindrical rotating body 86 in the initial state before the motor 50 rotates. Is set. Then, when the first rod-like rotating body 84 rotates about 20 ° from the neutral position, the protrusion 84b comes into contact with the protrusion 86a of the first cylindrical rotating body 86 as shown in FIG. Thereafter, when the first rod-shaped rotating body 84 further rotates in the same direction, the first cylindrical rotating body 86 starts rotating integrally with the first rod-shaped rotating body 84.

  In the initial state, the first cylindrical rotating body 86 is set at a neutral position where the protrusion 86 a is positioned in the middle of the protrusion 88 a of the second rod-shaped rotating body 88. And if the 1st cylindrical rotating body 86 rotates about 20 degrees, the protrusion 86a will contact | abut to the protrusion 88a of the 2nd rod-shaped rotating body 88, and if the 1st cylindrical rotating body 86 further rotates in the same direction after this, The second rod-shaped rotating body 88 starts to rotate together with the first cylindrical rotating body 86.

  As shown in FIG. 7A, in the initial state, the second rod-shaped rotating body 88 is set at an intermediate position where the protrusion 88c is positioned in the middle of the protrusion 90a of the second cylindrical rotating body 90. Then, when the second rod-shaped rotating body 88 rotates about 80 °, the projection 88c comes into contact with the projection 90a of the second cylindrical rotating body 90 as shown in FIG. When the body 88 rotates in the same direction, the second cylindrical rotating body 90 starts rotating together with the second rod-shaped rotating body 88.

  In the initial state, the second cylindrical rotating body 90 is set at an intermediate position where the protrusion 90 a is positioned in the middle of the protrusion 92 a of the third rod-shaped rotating body 92. When the second cylindrical rotator 90 rotates about 80 °, the protrusion 90a comes into contact with the protrusion 92a of the third rod-shaped rotator 92. Thereafter, when the second cylindrical rotator 90 further rotates in the same direction, The third rod-shaped rotating body 92 starts rotating together with the second cylindrical rotating body 90. When the third rod-shaped rotating body 92 rotates, the projection 94a of the cylinder 94 is pressed by the cam groove 92c, and the cylinder 94 moves along the longitudinal direction of the third rod-shaped rotating body 92. Then, the second lens 40 moves integrally with the cylindrical body 94.

  Thus, since the rotating shaft 54 is divided into a plurality of members and each member is connected by a connecting mechanism having a predetermined rotational play, the first rod-shaped rotating body 84 that rotates first is the third rod-shaped member that rotates last. The number of members that rotate together up to the rotating body 92 increases stepwise (that is, the rotational inertia force gradually increases). Thereby, compared with the case where a rotating shaft is comprised from one member, the burden to a motor can be reduced and even if the driving force of a motor is small, a rotating shaft can be rotated reliably. Further, since a predetermined time lag is generated from the start of rotation of the motor to the start of movement of the lens, the lens does not react sensitively to the movement of the motor. Further, when the rotating shaft is constituted by one member, the weight of the member to be rotated at the start of the movement of the lens is heavy, and it is necessary to rotate the motor with a large torque. For this reason, there is a problem that the lens moves greatly and it is difficult to finely adjust the position of the lens. However, this embodiment does not have such a problem.

  Further, although the burden on the motor increases as the number of members that rotate together increases, in this embodiment, the amount of rotational play increases as the number of members that rotate together increases (in this embodiment, the first play) Whereas the maximum rotational play between the rod-shaped rotating body 84, the first cylindrical rotating body 86, and the second rod-shaped rotating body 88 is about 40 °, the second rod-shaped rotating body 88 and the second cylindrical rotating body. 90, and the maximum rotational play between the third rod-shaped rotating bodies 92 was about 160 °). For this reason, as the number of members rotated together increases, the next member can be rotated in a more vigorous state (in a state where the rotational inertia force is increased), so the amount of rotational play between each member Compared with the case where the values are equal, the burden on the motor can be further reduced.

  Hereinafter, a flow in which the processor device 11 controls the motor 50 to perform zooming of a captured image will be described. As shown in FIG. 8, when the power of the processor device 11 is turned on, the processor device 11 starts to supply power to the camera module 30 and controls the CCD 34 to start capturing an image in the inspection hole. Then, the captured image is displayed on the monitor 12.

  The processor device 11 controls the motor 50 each time the magnification button 21 is pressed, and the reduction position (wide position) on the first lens 38 side and the enlargement position (tele position) on the third lens 42 side. The second lens 40 is switched and moved. Furthermore, every time the position of the second lens 40 is switched (every zooming), the processor device 11 controls the motor 50 to return each member of the rotating shaft 54 to the neutral position.

  Specifically, when zooming is completed and the second lens 40 is stopped, the direction (hereinafter referred to as reverse rotation) opposite to the rotation direction (hereinafter referred to as forward rotation direction) of the motor 50 immediately before the second lens 40 is stopped. Direction), the second cylindrical rotating body 90 is rotated about 80 ° and moved to the neutral position. Subsequently, the motor 50 is rotated in the forward rotation direction, and the second rod-shaped rotating body 88 is rotated by about 80 ° and moved to the neutral position. Further, thereafter, the motor 50 is rotated in the reverse direction, and the first cylindrical rotating body 86 is rotated by about 20 ° to move to the neutral position. Finally, the motor 50 is rotated in the forward rotation direction, and the first rod-shaped rotating body 84 is rotated by about 20 ° and moved to the neutral position.

  In the present invention, since it is only necessary to arrange the motor behind the prism to reduce the size of the camera module, the detailed configuration is not limited to the above embodiment and can be changed as appropriate. For example, in the said embodiment, although the example which comprises a rotary body from a some member was demonstrated, you may comprise a rotary body from one member. Moreover, also when a rotary body is comprised from several members, the number of members is not limited to five members like the said embodiment, Four or less may be sufficient and six or more may be sufficient.

  In the above embodiment, an example in which a DC motor is used as the motor has been described. However, a stepping motor that rotates by an amount corresponding to the number of supplied drive pulses may be used as the motor. When a stepping motor is used, the amount of rotation of the rotating body (each member constituting the rotating body) and the amount of movement of the lens can be controlled more finely.

  In the above embodiment, the example in which the plurality of members constituting the rotating body are returned to the neutral position after the movable lens is stopped has been described. However, this may be abolished and the motor may be stopped after the movable lens is stopped. . Moreover, you may make it return only the one part member which comprises a rotary body to a neutral position, without returning all the members which comprise a rotary body to a neutral position.

  Furthermore, when the moving direction of the movable lens is reversed, the motor may be rotated in the reverse rotation direction by half of the amount that the motor idles. Specifically, as in the above-described embodiment, when the moving direction of the lens is reversed, the first rod-shaped rotating body 84 needs to be reversed by about 400 ° (the first rod-shaped rotating body 84 is reversed by about 40 °. Then, the reverse rotation of the first cylindrical rotating body 86 is started, and then the first cylindrical rotating body 86 is rotated approximately 40 ° to start the reverse rotation of the second rod-shaped rotating body 88, and then the second rod-shaped rotating body 86 is started. The rotating body 88 is reversed by about 160 ° to start the reverse rotation of the second cylindrical rotating body 90. Finally, the rotation of the third rod-shaped rotating body 92 is started by reversing the second cylindrical rotating body by about 160 °. When the movable lens is stopped, the motor 50 may be rotated in the reverse direction so that the first rod-shaped rotating body 84 is reversed by about 200 °.

  Moreover, in the said embodiment, although the amount of rotation play between each member which comprises a rotating shaft was switched in two steps, it demonstrated in the example which sets the amount of rotation play between the members rotated later large, The amount of rotational play between the members may be set equal. Further, for example, the maximum amount of rotational play between the first rod-shaped rotating body and the first cylindrical rotating body is 20 °, and the amount of rotation play between the first cylindrical-shaped rotating body and the second rod-shaped rotating body is 20 °. The maximum amount of rotational play between the second rod-shaped rotating body and the second cylindrical rotating body is 80 °, and the rotational play between the second cylindrical rotating body and the third rod-shaped rotating body. The amount of rotational play may be switched to three or more stages so that the maximum amount of rotation is 160 °.

  Furthermore, in the said embodiment, it has the cylinder connected with the lens and the rotation around the rotating shaft was regulated, and the rotating shaft inserted into the cylinder, and the protrusion formed on the inner periphery of the cylinder was rotated. Although the description has been given of the configuration in which the lens moves together with the cylindrical body as the rotating shaft rotates by engaging with the cam groove formed on the outer periphery of the shaft, the present invention is not limited to this. For example, a cam groove may be provided on the inner periphery of the cylinder and a protrusion may be provided on the outer periphery of the rotating shaft. Further, the lens may be moved by a configuration in which a screw groove formed on the inner periphery of the cylinder and a screw thread formed on the outer periphery of the rotating shaft are engaged regardless of the cam groove and the protrusion. Of course, a screw thread may be provided on the inner periphery of the cylinder and a screw groove may be provided on the outer periphery of the rotating shaft.

  In the above embodiment, an example in which the zooming movable lens is moved to two positions, that is, the wide position and the tele position, that is, an example in which zooming is performed in two stages, has been described. Zooming may be performed. Of course, the zooming may be performed in a stepless manner.

  In the above-described embodiment, an example in which the zooming movable lens is moved by the motor disposed behind the prism has been described. However, the focus adjusting movable lens may be moved by a similar mechanism. Of course, two motors may be arranged behind the prism to move both the zooming movable lens and the focus adjusting movable lens.

  Further, in the above-described embodiment, the example in which the lens moving mechanism is disposed on the opposite side of the CCD with the objective optical system interposed therebetween (see FIG. 3) has been described, but the present invention is not limited to this. For example, as shown in FIG. 9, the lens moving mechanism 36 may be disposed at a position inclined with respect to a line connecting the circuit board 34 and the objective optical system.

  In the above-described embodiment, an example in which a CCD is used as the image sensor has been described. However, a CMOS image sensor may be used as the image sensor. Furthermore, in the said embodiment, although the lens barrel and the main body case were demonstrated in the example provided separately, you may provide these integrally. Furthermore, in the above embodiment, the example in which the present invention is applied to a medical endoscope has been described, but the present invention may be applied to an industrial endoscope.

DESCRIPTION OF SYMBOLS 2 Electronic endoscope system 10 Electronic endoscope 11 Processor apparatus 12 Monitor 13 Insertion part 17 Tip part 26 Observation window 30 Camera module 32 Objective optical system 34 Circuit board 35 CCD (Image sensor)
36 Lens moving mechanism 38 1st lens 40 2nd lens 42 3rd lens 44 Prism 50 Motor 52 Rotational force transmission mechanism 54 Rotating shaft 56 Drive shaft 84 1st rod-shaped rotating body 86 1st cylindrical rotating body 88 2nd rod-shaped rotating body 90 Second cylindrical rotating body 92 Third rod-shaped rotating body 84b, 86a, 88a, 88c, 90a, 92a Projection 92c Cam groove 94 Cylindrical body 94a Projection

Claims (11)

A photographic lens having a movable lens movable in the optical axis direction;
A prism that reflects subject light incident from the photographing lens in a direction substantially perpendicular to the optical axis direction;
A circuit board having an image sensor that photoelectrically converts an optical image formed through the photographing lens and the prism;
A lens moving mechanism that has a rotating shaft that is formed long in the optical axis direction and is disposed on the side of the photographing lens, and that moves the movable lens in the optical axis direction by rotation of the rotating shaft;
A motor having a rotatable drive shaft and rotating the drive shaft in response to an external power supply;
A rotational force transmission mechanism for transmitting the rotational force of the drive shaft to the rotational shaft, and
An endoscope camera module, wherein the motor is disposed behind the prism in a state where the drive shaft is parallel to the optical axis direction. The rotating shaft is composed of a plurality of rotating bodies,
Each rotating body is arranged in the optical axis direction of the insertion portion from the back side on which the drive shaft is provided toward the front side on which the movable lens is provided and rotates around a common axis, and a predetermined amount 2. Adjacent shaft bodies are connected to each other so as to have a rotational play, and the rotational force of the drive shaft is sequentially transmitted from the back-side rotating body to the front-side rotating body. The endoscope camera module described. At least three of the rotating bodies are provided,
2. The endoscope camera module according to claim 1, wherein angles of rotation play set between adjacent rotating bodies are different from each other.   The endoscope camera module according to claim 3, wherein an angle of the rotation play is set to be larger from a back side to a front side. As the rotating body, two types of rotating bodies, a rod-shaped rotating body and a cylindrical rotating body, are used, and these are alternately arranged,
The rod-shaped rotating body includes outer peripheral protrusions arranged at equal intervals along the outer periphery of the end portion on the cylindrical rotating body side,
The cylindrical rotating body is formed to have an inner diameter larger than the outer periphery of the rod-shaped rotating body including the outer peripheral protrusion, and is disposed so as to surround the rod-shaped rotating body together with the outer peripheral protrusion, and on the movement path of the outer peripheral protrusion. The inserted inner peripheral protrusion is erected on an inner wall, and the inner peripheral protrusion is pressed by the outer peripheral protrusion to rotate integrally with the rod-shaped rotating body. The endoscope camera module described.   The lens moving mechanism reverses the motor or repeats the reverse and normal rotation of the motor within a range in which the lens is not moved after the lens is moved, and the drive shaft is rotated in any direction. 3. The motor is stopped after moving each rotating body to a neutral position where the amount of rotation from the start of rotation until all the rotating bodies rotate together is substantially the same amount. The endoscope according to any one of -5. A body case for holding the photographing lens, the lens moving mechanism, and the rotation shaft;
7. The motor case according to claim 1, further comprising a motor case that holds the motor and the rotational force transmission mechanism and is fixed to a back side of the main body case and integrated with the main body case. The endoscope camera module described.   The lens movement mechanism, the rotation shaft, the rotational force transmission mechanism, and the drive shaft are covered with at least one of the main body case and the motor case, and are shielded from the outside. Item 8. The camera module according to Item 7.   The camera module according to claim 6 or 7, wherein the motor is bonded to the motor case with an adhesive having thermal conductivity. It is arranged so as to surround the rotating shaft, and has a cylindrical body whose rotation around the rotating shaft is restricted,
The lens moving mechanism moves the movable lens by moving the cylindrical body along the longitudinal direction of the rotation shaft,
The cylindrical body has a protrusion on the inner wall that engages with a helical cam groove formed on the outer periphery of the rotating shaft or a helical cam groove that engages with a protrusion formed on the outer periphery of the rotating shaft. The endoscope according to any one of claims 1 to 9, wherein the endoscope slides in a longitudinal direction of the rotation shaft as the rotation shaft rotates. It is arranged so as to surround the rotating shaft, and has a cylindrical body whose rotation around the rotating shaft is restricted,
The lens moving mechanism moves the movable lens by moving the cylindrical body along the longitudinal direction of the rotation shaft,
The cylindrical body is a spiral thread that engages with a spiral thread groove formed on the outer periphery of the rotating shaft, or a spiral that engages with a spiral thread formed on the outer periphery of the rotating shaft. The endoscope according to any one of claims 1 to 9, wherein a threaded groove is provided on an inner wall and slides in a longitudinal direction of the rotary shaft as the rotary shaft rotates.

Images