JP5732422B2 - Electronic endoscope device - Google Patents

Description

  The present invention relates to an electronic endoscope apparatus, and more particularly to an electronic endoscope apparatus in which a zoom lens is built in a distal end portion.

  FIG. 8 is a longitudinal cross-sectional view of an imaging system at the distal end portion of a conventional electronic endoscope apparatus with a built-in zoom lens. At the back of the observation window 2 provided on the distal end surface of the endoscope scope, a lens barrel 4 that holds an objective optical system 3 for taking in image light of a site to be observed in the body cavity is disposed.

  The lens barrel 4 is attached so that the optical axis of the objective optical system 3 is parallel to the central axis of the portion of the endoscope scope that is inserted into the body cavity of the patient. At the rear end of the lens barrel 4, a prism 6 that guides the image light of the site to be observed that has passed through the objective optical system 3 toward the imaging chip 5 by bending it at a substantially right angle is disposed.

  The imaging chip 5 includes a solid-state imaging device such as a CCD type or a CMOS type, and a peripheral circuit that drives the solid-state imaging device and inputs / outputs signals. The imaging chip 5 is mounted on the support substrate 7, and the imaging surface (light receiving surface) of the imaging chip 5 is disposed so as to face the emission surface of the prism 6.

  The objective optical system 3 constitutes a zoom lens. In the illustrated example, the objective optical system 3 includes moving lenses 3b and 3c in addition to the fixed lenses 3a and 3d. By moving the movable lenses 3b and 3c along the optical axis and changing the distance between them and the distance from the fixed lenses 3a and 3d, the imaging chip 5 can capture an image in which the site to be observed is enlarged at a desired magnification. It is like that.

  Cylindrical cam members 7a and 7b are attached to the movable lenses 3b and 3c, respectively. Projections 7c and 7d are provided on the inner peripheral surfaces of the central holes of the cylindrical cam members 7a and 7b, and a cam shaft 8 is inserted into the central hole. On the peripheral surface of the cam shaft 8, cam grooves 8a and 8b that are slidably fitted to the protrusions 7c and 7d are formed.

  When the cam shaft 8 is rotationally driven around the axis, the cylindrical cam members 7a and 7b move in the axial direction along the cam grooves 8a and 8b, and the moving lenses 3b and 3c become the optical axis of the objective optical system 3. It is supposed to move along.

  A power transmission wire (flexible shaft) 9 is attached to the base end portion of the cam shaft 8. The power transmission wire 9 is inserted into an operation unit (not shown) of the endoscope scope and is driven to rotate by a motor provided in the operation unit.

  The endoscope operator operates the motor enlargement / reduction instruction switch provided in the operation unit to rotate / reverse the motor to enlarge / reduce the captured image.

  In such an electronic endoscope apparatus that adjusts the magnification of the zoom lens with the power transmission wire 9, the length of the power transmission wire 9 is as long as about 3 m. In addition, since the endoscope scope is bent and inserted into the body cavity of the patient, the motor power can be transmitted to the camshaft 8 satisfactorily.

  However, in recent years, endoscope scopes are in the direction of reducing the diameter in order to reduce the burden on the patient and are currently 9 mm in diameter, but further reduction in diameter has been achieved. For this reason, torque transmission by the power transmission wire 9 is difficult. Therefore, as described in Patent Document 1 below, it is effective to incorporate the motor itself in the distal end portion of the endoscope scope.

  However, it is necessary to manufacture a motor specially designed for an electronic endoscope in terms of torque, rotational speed, etc. to be produced, and this increases the manufacturing cost of the electronic endoscope apparatus. Therefore, a method of using a general-purpose small motor, which has become easy to procure due to recent progress in component miniaturization technology, is being sought.

  The problem here is that the general-purpose small motor has no problem in size, but the rotational speed is too high. That is, it is not possible to obtain sufficient torque for rotationally driving the camshaft 8.

  This problem can be solved by incorporating a speed reduction mechanism in the distal end portion of the endoscope scope together with a motor as described in Patent Documents 2 and 3 below, for example. However, it is difficult to apply the techniques of Patent Documents 2 and 3 when the diameter of the endoscope scope is still large to the distal end portion of the endoscope scope whose diameter is reduced.

  For example, since the speed reduction mechanism described in Patent Document 2 uses a planetary gear mechanism, the diameter of the speed reduction mechanism is increased, and it is difficult to incorporate the speed reduction mechanism in the distal end portion of the endoscope scope that is reduced in diameter.

  Moreover, since the speed reduction mechanism described in Patent Document 3 must be provided on the opposite side of the imaging system with the motor as the center, the diameter of the endoscope scope is increased. In addition, an endoscope scope having only an imaging system built in the distal end portion may be used. However, in the case of an endoscope scope having a light guide through which illumination light passes, a forceps channel, and an air / water feeding channel together, a motor and A problem arises in the ease of assembly of the speed reduction mechanism when the diameter of the speed reduction mechanism is reduced.

Japanese Patent No. 3573023 Japanese Patent Laid-Open No. 2001-174715 Japanese Patent Publication No. 63-33855 (Fig. 6)

  SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom lens built-in type electronic endoscope apparatus that incorporates a motor with a speed reduction mechanism at the tip, which is suitable for reducing the diameter and is easy to assemble.

  An electronic endoscope apparatus according to the present invention moves along an optical element of an imaging element built in an endoscope scope tip, an objective optical system provided in front of the imaging element, and the optical axis of the objective optical system A cam member coupled to the moving lens and a direction along the optical axis, and the direction along the optical axis is rotated as a rotation axis so that the moving lens is moved along the optical axis via the cam member. A camshaft to be moved, a gear portion that is integrally connected to an end of the camshaft to rotate and rotates the camshaft, a motor disposed coaxially with the camshaft, and an output of the motor A gear support shaft provided in parallel between the shaft and the optical axis; a reduction gear disposed between the output shaft of the motor and the gear support shaft and between the gear support shaft and the gear portion; And a mechanism.

  According to the present invention, a motor and a speed reduction mechanism can be incorporated without enlarging the diameter of the endoscope scope tip, and a general-purpose small motor can be used. Further, since the speed reduction mechanism is provided at a position protected by the motor and the imaging system member, the assembling property of each member to the endoscope scope distal end is improved.

1 is an overall system configuration diagram of an endoscope system (electronic endoscope apparatus) according to an embodiment of the present invention. It is a front view which shows the front end surface of the endoscope scope shown in FIG. It is a control block diagram of the endoscope system shown in FIG. It is a principal part longitudinal cross-sectional view of the endoscope scope front-end | tip part shown in FIG. FIG. 5 is an exploded perspective view around a cam shaft for adjusting a motor, a speed reduction mechanism, and a zoom lens magnification shown in FIG. 4. FIG. 5 is an enlarged view of the motor and the speed reduction mechanism shown in FIG. 4. It is the figure seen from the arrow A direction of FIG. It is a longitudinal cross-sectional view of the front-end | tip part of the endoscope scope using the conventional flexible shaft.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a system configuration diagram of an electronic endoscope apparatus according to an embodiment of the present invention. An electronic endoscope apparatus (endoscope system) 10 according to the present embodiment includes an endoscope scope 12, a processor device 14 and a light source device 16 that constitute a main body device.

  The endoscope scope 12 includes a flexible insertion portion 20 that is inserted into a body cavity of a patient (subject), a hand operation portion 22 that is connected to a proximal end portion of the insertion portion 20, a processor device 14, and And a universal cord 24 connected to the light source device 16.

  A distal end portion 26 is connected to the distal end of the insertion portion 20, and an imaging chip 54 (see FIG. 3) for body cavity imaging is built in the distal end portion 26.

  Behind the distal end portion 26 is provided a bending portion 28 in which a plurality of bending pieces are connected. When the angle knob 30 provided in the hand operation unit 22 is operated, the bending unit 28 is bent / moved in the vertical and horizontal directions by pushing / pulling the wire inserted in the insertion unit 20. Thereby, the front-end | tip part 26 is orientated in the desired direction within a body cavity.

  A connector 36 is provided at the base end of the universal cord 24. The connector 36 is of a composite type and is connected to the light source device 16 in addition to being connected to the processor device 14.

  The processor device 14 supplies power to the endoscope scope 12 via a cable inserted into the universal cord 24, controls the driving of the imaging chip 54, and also captures the imaging signal transmitted from the imaging chip 54 via the cable. The received image signal is subjected to various signal processing and converted into image data.

  The image data converted by the processor device 14 is displayed as an endoscopic image (observation image) on a monitor 38 connected to the processor device 14 by a cable. The processor device 14 is also electrically connected to the light source device 16 via the connector 36, and comprehensively controls the operation of the endoscope system 10 including the light source device 16.

  FIG. 2 is a front view showing the distal end surface 26 a of the distal end portion 26 of the endoscope scope 12. As shown in FIG. 2, an observation window 40, an illumination window 42, a forceps outlet 44, and an air / water supply nozzle 46 are provided on the distal end surface 26 a of the distal end portion 26.

  The observation window 40 is arranged eccentric to the center and one side of the distal end surface 26a. Two illumination windows 42 are arranged at symmetrical positions with the observation window 40 as the center, and irradiate the observation site in the body cavity with illumination light from the light source device 16.

  The forceps outlet 44 is connected to a forceps channel (not shown) disposed in the insertion portion 20 and communicates with a forceps port 34 (see FIG. 1) provided in the operation portion 22. Various treatment tools having an injection needle, a high-frequency knife or the like disposed at the distal end are inserted into the forceps port 34, and the distal ends of the various treatment instruments are ejected from the forceps outlet 44 into the body cavity.

  The air supply / water supply nozzle 46 is supplied from an air supply / water supply device built in the light source device 16 in accordance with an operation of an air supply / water supply button 32 (see FIG. 1) provided in the hand operation unit 22. Washing water or air is jetted toward the observation window 40 or the body cavity.

  FIG. 3 is a block diagram showing a control system of the electronic endoscope apparatus 10. An imaging chip 54 is built in the distal end portion 26 of the endoscope scope 12. In this embodiment, the imaging chip 54 includes a CMOS solid-state imaging device 58 and its peripheral circuit. The peripheral circuit includes an analog signal processing circuit (AFE: analog front end) 72 and a TG (timing generator) 78.

  At the distal end portion 26 of the endoscope scope 12, in addition to the imaging chip 54, a zoom lens type objective optical system 50 that collects subject light on the imaging surface of the solid-state imaging device 58 through the observation window 40, and the objective optical system 50 A motor 51 and a speed reduction mechanism 52 for adjusting the zoom position and a CPU 80 are provided.

  Electric power is supplied to the motor 51 via a cable inserted into the endoscope scope 12, and a control drive signal of the enlargement / reduction magnification is applied according to an instruction from the CPU 80. A manual operation signal is input to the CPU 80 from an enlargement / reduction switch (not shown) provided in the hand operation unit 22 of FIG.

  The TG 78 generates a driving pulse (vertical / horizontal scanning pulse, reset pulse, etc.) for the solid-state imaging device 58 and a synchronization pulse for the AFE 72 based on the control of the CPU 80. The solid-state image sensor 58 is driven by a drive pulse input from the TG 78, photoelectrically converts an optical image formed on the imaging surface of the solid-state image sensor 58 via the objective optical system 50, and outputs it as an imaging signal.

  A large number of pixels (not shown) are arranged in a matrix on the imaging surface of the solid-state imaging element 58, and each pixel is provided with a photosensor (photoelectric conversion element). Light incident on the imaging surface of the solid-state imaging device 58 is accumulated as a charge in the photosensor of each pixel. Then, by the vertical and horizontal scanning by the vertical scanning circuit and the horizontal scanning circuit (both not shown), the signal charge amount accumulated in the photosensor of each pixel is sequentially read out as a pixel signal, and has a predetermined frame rate. Is output.

  The solid-state image sensor 58 is a solid-state image sensor of a single plate color imaging system provided with a color filter composed of a plurality of color segments (for example, a primary color filter having a Bayer array). The configuration of a signal readout circuit that reads out the accumulated charge of each photosensor of the solid-state imaging device 58 as an imaging signal is well known in the art. For example, a general configuration such as a 3-transistor configuration or a 4-transistor configuration can be applied. The description is omitted here.

  The AFE 72 includes a correlated double sampling (CDS) circuit, an automatic gain circuit (AGC), and an A / D converter. The CDS circuit performs correlated double sampling processing on the imaging signal output from the solid-state imaging device 58 to remove reset noise and amplifier noise generated in the solid-state imaging device 58.

  The AGC amplifies the image signal from which noise has been removed by the CDS circuit with a gain (amplification factor) designated by the CPU 80. The A / D converter converts the imaging signal amplified by the AGC into a digital signal having a predetermined number of bits and outputs the digital signal. The imaging signal (digital imaging signal) digitized and output by the AFE 72 is input to the processor device 14 through a cable.

  The processor device 14 includes a CPU 82, a ROM 84, a RAM 85, an image processing circuit (DSP) 86, and a display control circuit 88.

  The CPU 82 controls each part in the processor device 14 and communicates with the CPU 80 in the endoscope scope 12 and a CPU 104 in the light source device 16 described later, and comprehensively controls the entire electronic endoscope device 10. To do. In the ROM 84, various programs for controlling the operation of the processor device 14, control data, and the like are stored in advance. The RAM 85 temporarily stores programs executed by the CPU 82 and data.

  The DSP 86 performs color interpolation, color separation, color balance adjustment, gamma correction, image enhancement processing, and the like on the imaging signal input from the AFE 72 under the control of the CPU 82 to generate image data.

  The image data output from the DSP 86 is input to the display control circuit 88, and the display control circuit 88 converts the image data input from the DSP 86 into a signal format corresponding to the monitor 38 and displays it on the screen of the monitor 38.

  The operation unit 90 of the processor device 14 is provided with a mode switching button for selecting or switching the operation mode of the solid-state imaging device 58, and various buttons for receiving other user instruction inputs.

  The light source device 16 includes a main light source 100, a main light source driving circuit 101, a special light source 102, a special light source driving circuit 103, a CPU 104, and a multiplexing unit 105. The CPU 104 communicates with the CPU 82 of the processor device 14 and controls the main light source driving circuit 101 and the special light source driving circuit 103.

  The main light source 100 emits white light, and the special light source 102 emits special light in a narrow band centered at, for example, 420 nm. The white light or special light is emitted to the incident end 120 b of the light guide 120 through the multiplexing unit 105.

  When the inside of the body cavity is observed with the electronic endoscope device 10 configured as described above, the endoscope scope 12, the processor device 14, the light source device 16, and the monitor 38 are turned on, and the internal endoscope is turned on. Inserting the insertion portion 20 of the endoscope scope 12 into a body cavity and observing a moving image in the body cavity captured by the solid-state imaging device 58 on the monitor 38 while illuminating the body cavity with illumination light from the light source device 16. become.

  When the endoscope operator views an observation image on the monitor 38 and wants to view an enlarged image, the endoscope operator manually operates an enlargement / reduction instruction switch provided on the hand operation unit 22.

  This switch signal is captured by the CPU 80, and the CPU 80 outputs a drive control signal to the motor 51 to control the magnification of the objective optical system 50 so as to obtain the corresponding magnification. Note that the enlargement / reduction instruction switch may be provided in the operation unit 90 of the processor device 14.

  FIG. 4 is a longitudinal sectional view of the zoom magnification adjusting unit 110 built in the distal end portion 26 of the endoscope scope 12. The zoom magnification adjustment unit 110 is provided in the imaging system storage unit 150.

  In addition to the zoom lens type objective optical system 50, the imaging chip 54 described with reference to FIG. The zoom magnification adjusting unit 110 moves the positions of the moving lenses 50a and 50b among the various lenses constituting the objective optical system 50.

  The zoom magnification adjusting unit 110 includes a cam shaft 111 and two cylindrical cam members 112 and 113 that are slidably fitted on the cam shaft 111. The moving lens 50 a is attached to the cylindrical cam member 112, and the moving lens 50 b is attached to the cylindrical cam member 113.

  FIG. 5 is an exploded perspective view of the zoom magnification adjusting unit 110. Hereinafter, a description will be given with reference to FIGS. 4 and 5.

  Cam grooves 114 and 115 are formed on the outer peripheral surface of the cam shaft 111. A screw member 116 is screwed into the outer shell portion of the cylindrical cam member 112, and a tip end portion 116 a of the screw member 116 is provided so as to protrude into the cam groove 114. The screw member 117 is screwed into the outer shell portion of the cylindrical cam member 113, and the tip end portion 117 a of the screw member 117 is provided so as to protrude into the cam groove 115.

  As a result, when the cam shaft 111 rotates, the cam grooves 114 and 115 rotate, and the tip portions 116 a and 117 a of the screw members 116 and 117 slidably engaged with the cam grooves 114 and 115 are Move in the direction.

  As a result, the moving lenses 50a and 50b move in the axial direction according to the shape of the cam shaft peripheral surface of the cam grooves 114 and 115, respectively, and the magnification of the objective optical system 50 is adjusted.

  The cam shaft 111 is housed in the housing 120 of the zoom magnification adjusting unit 110. The housing 120 includes a small-diameter portion 120a in which a cylindrical inner space is narrowed on the proximal end side (the proximal side of the endoscope scope 12). A flange that is integrally projected on the outer periphery of the cam shaft 111 so that the cam shaft 111 housed in the cylindrical inner space of the housing 120 can rotate around the shaft and cannot move in the axial direction. 111a has a structure that abuts slidably on the side wall surface of the small diameter portion 120a.

  A female screw hole is threaded in the axial direction at the center of the end of the cam shaft 111 on the side where the flange 111a is provided. The front male screw portion 125a of the fifth gear 125 (the first to fourth gears will be described later) is screwed into the female screw hole. As a result, the fifth gear 125 rotates integrally with the cam shaft 111.

  A flange 125b protrudes from the outer periphery of the middle portion of the fifth gear 125. When the front male screw portion 125a is screwed and fixed to the cam shaft 111, the flange 125b and the flange 111a of the cam shaft 111 sandwich the side wall surface of the small diameter portion 120a of the housing 120 so as to be slidable. Yes.

  The small-diameter portion 120a of the housing 120 functions as a bearing for the camshaft 111, whereby the fifth gear 125 and the camshaft 111 can rotate together and cannot move in the axial direction. Note that a small-diameter portion may also be provided on the front end side of the housing 120 to serve as a front end side bearing of the cam shaft 111.

  A gear portion 125 c is engraved on the rear end portion side of the fifth gear 125. The rotational force of the motor 51 is decelerated and transmitted to the gear portion 125c through the first gear 121, the second gear 122, the third gear 123, and the fourth gear 124.

  Hereinafter, the speed reduction mechanism 52 including the first gear 121 to the fifth gear 125 will be described with reference to an enlarged view of FIG.

  A first gear 121 is externally fitted and fixed to the tip of the output shaft 51 a of the motor 51. A gear support shaft 126 parallel to the output shaft 51 a is disposed between the motor 51 and the imaging system storage unit 150.

  The rear end portion 126 a of the gear support shaft 126 is supported by the first bearing 127. The first bearing 127 also serves as a motor holder that fixes and supports the rear end portion of the motor 51. This motor holder is fixedly installed on the main body structure of the endoscope scope 12. The support shaft 126 may be a fixed shaft (a shaft that does not rotate).

  A third bearing 128 is fitted and fixed to the rear end of the housing 120 that houses the camshaft 111, and a gear support shaft 126 is inserted into a bearing hole 128 a (see FIG. 5) provided in the third bearing 128. The front end portion 126b is inserted and supported.

  A large-diameter hole 128b (see FIG. 5) is formed in the center of the third bearing 128, and the gear portion 125c of the fifth gear 125 is accommodated in the hole 128b.

  The first gear 121 that is externally fitted and fixed to the distal end portion of the output shaft 51a of the motor 51 is constituted by a two-stage gear in which a large-diameter gear portion 121a and a small-diameter gear portion 121b are integrally molded.

  Since the large gear portion 121a of the first gear 121 is not used, only the small gear portion 121b is required. However, the first gear 121 also has a large-diameter gear portion 121a because cost reduction is achieved by using common parts with the second gear 122 and the third gear 123.

  The second gear 122 is also composed of a two-stage gear in which a large-diameter gear portion 122 a and a small-diameter gear portion 122 b are integrally formed, and is rotatably fitted on the gear support shaft 126. The large diameter gear portion 122 a meshes with the small diameter gear portion 121 b of the first gear 121.

  The third gear 123 is also composed of a two-stage gear in which a large-diameter gear portion 123a and a small-diameter gear portion 123b are integrally formed, and is rotatably fitted around a short support shaft 131. The front end portion of the support shaft 131 is supported by a bearing hole 129a (see FIG. 5) provided in the second bearing 129 that is fitted and fixed to the third bearing 128 at the rear end portion. A drop-off prevention ring 132 for the third gear 123 is attached to the outer periphery of the rear end portion of the support shaft 131.

  The large diameter gear portion 123a of the third gear 123 meshes with the small diameter gear portion 122b of the second gear 122. The fourth gear 124 that meshes with the small-diameter gear portion 123 b of the third gear 123 is provided so as to be rotatably fitted to the gear support shaft 126. A spacer 133 is provided between the second gear 122 and the fourth gear 124 that are rotatably fitted to the gear support shaft 126.

  The fourth gear 124 is also a two-stage gear of a large-diameter gear portion 124a that meshes with the small-diameter gear portion 123b of the third gear 123 and a small-diameter gear portion 124b that is integrally connected thereto. The small diameter gear portion 124b is formed longer than the small diameter gear portions 121a to 123a of the first, second, and third gears 121 to 123.

  Then, the small-diameter gear portion 124 is inserted with play in a large-diameter through hole 129b (see FIG. 5) drilled in the end wall of the second bearing 129, and the tip portion thereof is the gear portion 125c of the fifth gear 125. Is engaged. The gear portion 125c has the same size as the large-diameter gear portion of the two-stage gear that constitutes each of the first gear to the fourth gear.

  A rotation positioning pin 134 is inserted into a hole penetrating the second bearing 129 and the third bearing 128 so that the second bearing 129, the third bearing 128, and the housing 120 of the camshaft 111 do not rotate relative to each other. The tip of the pin 134 is fitted into a bottomed hole provided in the housing 120.

  With the above configuration, when the enlargement / reduction instruction switch is operated, power is supplied to the terminals 51b and 51c of the motor 51, and the output shaft 51a is driven to rotate forward at high speed. Thereby, the 1st gear 121 rotates at high speed.

  The rotation of the first gear 121 is decelerated when transmitted to the second gear 122, and is further decelerated when transmitted to the third gear 123. The rotation of the third gear 123 is further decelerated when it is transmitted to the fourth gear 124, and is further decelerated when it is transmitted to the fifth gear 125, and the torque necessary to rotate the camshaft 111 is obtained.

  When the motor 51 starts reverse rotation by operating the enlargement / reduction instruction switch, torque is transmitted through the transmission path 135 similar to the above, and the camshaft 111 rotates reversely.

  7 is an arrow view of the zoom magnification adjusting unit 110 and the imaging system storage unit 150 as viewed from the direction of arrow A in FIG. That is, FIG. 7 shows a view of the zoom magnification adjustment unit 110 and the imaging system storage unit 150 as viewed from the rear side. The output shaft 51a of the motor 51, the gear shaft 126 of the speed reduction mechanism 52, and the imaging system storage unit 150 are shown. The positional relationship with the optical axis 150a is shown.

  In the present embodiment, the gear support shaft 126 of the speed reduction mechanism 52 is provided substantially on a line connecting the motor output shaft 51a and the optical axis 150a. That is, since the speed reduction mechanism 52 of this embodiment is disposed at a hidden position between the motor 51 and the imaging system storage unit 150, it is protected by both.

  Accordingly, when other members such as a forceps channel, an air / water supply channel, a light guide, or the like are assembled to the distal end portion of the endoscope scope, the speed reduction mechanism 52 is protected from interference and collision with these members. For this reason, the housing | casing which accommodates the deceleration mechanism 52 becomes unnecessary, and the cost reduction and further diameter reduction of an endoscope scope can be achieved.

  The size of the cam shaft 111 and the cylindrical cam members 112 and 113 and the size of the lens of the objective optical system do not change so much as long as the endoscope scope is made thinner. For this reason, the distance between the flexible shaft 9 in FIG. 8 and the optical axis of the imaging system is substantially the same as the distance between the motor 51 and the optical axis 150a in FIG.

  That is, the speed reduction mechanism 52 of this embodiment is provided in a dead space between the conventional cam shaft base end portion (cam shaft side connection portion of the flexible shaft 9) and the imaging system in FIG. The mirror scope can be installed without increasing the diameter. That is, the speed reduction mechanism 52 of the present embodiment, that is, the speed reduction mechanism 52 having a two-axis configuration including the motor shaft 51a and the support shaft 131 coaxial with the motor shaft 51a and the gear support shaft 126 parallel to them, has a small diameter of the endoscope scope. It is advantageous for the conversion.

  Further, the motor shaft 51a and the support shaft 131 shown in FIG. 6 and the central axes of the fifth gear 125 and the cam shaft 111 are arranged coaxially, and the gear support shaft 126 is arranged in parallel to the motor output shaft 51a. . By aligning and assembling the bearings 128 and 129 with the pins 134 to the housing 120 of the zoom magnification adjusting unit 110, the support shaft 131 can be easily assembled coaxially with the fifth gear 125. In addition, the gear support shaft 126 can be easily assembled in parallel to the support shaft 131.

  The rear portion 1/3 of the motor 51 is inserted into the motor mounting hole of the first bearing 127 serving as a motor holder, and the end 126a of the gear shaft 126 arranged adjacent to the motor 51 is attached to the shaft. Insert into the hole.

  Thereby, the parallelism between the motor output shaft 51a and the gear support shaft 126 is guaranteed. In this state, by inserting the leading end 126b of the gear support shaft 126 into the holes 129b and 128a in FIG. 5, the meshing property between the gears can be maintained while maintaining the parallelism of the motor output shaft 51a and the gear support shaft 126. Good high-precision assembly is facilitated.

  In the above-described embodiment, the speed reduction mechanism 52 has a five-gear configuration of first to fifth gears. However, the present invention is not limited to this, and the three-gear configuration or a configuration of seven or more gears may be used. It goes without saying that it is good.

  As described above, the electronic endoscope apparatus according to the present embodiment includes an image pickup element built in the distal end portion of the endoscope scope, an objective optical system provided in front of the image pickup element, and the objective optical system. A cam member connected to a moving lens that moves along the optical axis, and a cam member that is provided in the direction along the optical axis and rotates about the direction along the optical axis as a rotation axis. A cam shaft that moves in a direction along the optical axis, a gear portion that is integrally connected to an end portion of the cam shaft and is rotated and driven, and is coaxially disposed with the cam shaft. A motor, a gear support shaft provided in parallel between the output shaft of the motor and the optical axis, and between the output shaft of the motor and the gear support shaft and between the gear support shaft and the gear portion. And a reduction gear mechanism disposed therebetween.

  In the electronic endoscope apparatus of the embodiment, the bearing that supports one end of the gear support shaft also serves as the motor holder of the motor, and the motor holder holds the output shaft of the motor and the gear support shaft in parallel. To do.

  Further, the reduction gear mechanism of the electronic endoscope apparatus according to the embodiment is configured by combining a plurality of two-stage gears in which a large-diameter gear portion and a small-diameter gear portion are integrally molded.

  The reduction gear mechanism of the electronic endoscope apparatus according to the embodiment includes a first gear fixed to the output shaft and a large-diameter gear portion rotatably attached to the gear support shaft. The second gear, which is the two-stage gear that meshes, and the large-diameter gear portion that meshes with the small-diameter gear portion of the second gear that is separated from the output shaft and rotatably supported on a support shaft that is coaxial with the cam shaft. A third gear comprising the two-stage gear, and a large-diameter gear portion meshed with a small-diameter gear portion of the third gear which is rotatably attached to the gear support shaft, and a small-diameter gear portion is engaged with the gear portion of the camshaft. A fourth gear that meshes.

  In the electronic endoscope apparatus according to the embodiment, a bearing portion that supports one end portion of the gear support shaft is attached to a housing that houses the cam shaft and the gear portion of the cam shaft. A bearing portion that supports the support shaft of the third gear is attached, and the two bearing portions are positioned with respect to the housing by a positioning member.

  In the electronic endoscope apparatus according to the embodiment, the first gear is constituted by the small-diameter gear portion of the two-stage gear, and the first gear, the second gear, and the third gear are formed by common parts. Endoscopic device.

  In the electronic endoscope apparatus of the embodiment, the gear portion of the camshaft is made the same size as the large-diameter gear portion of the two-stage gear, so that the reduction ratio of the reduction mechanism can be easily calculated.

  According to the electronic endoscope apparatus of the above-described embodiment, the motor and the speed reduction mechanism can be incorporated without increasing the diameter of the endoscope scope tip, and a general-purpose small motor can be used. In addition, since the speed reduction mechanism is provided at a position protected by the motor and the imaging system, the assembling property of each member to the endoscope scope distal end is improved.

  Since the electronic endoscope apparatus according to the present invention can adjust the magnification of the zoom lens using a general-purpose motor, the cost of the endoscope scope can be reduced and the diameter can be reduced. It is useful when applied to a built-in electronic endoscope apparatus.

10 Electronic Endoscope Device (Endoscope System)
12 Endoscope scope 26 Endoscope scope tip 40 Observation window 50 Objective optical system 50a, 50b Moving lens 51 Motor 51a Motor output shaft 52 Deceleration mechanism 54 Imaging chip 58 Solid-state imaging device 110 Zoom magnification adjustment unit 110 Housing 111 Cam Shafts 112, 113 Cylindrical cam members 114, 115 Cam groove 121 First gear 122 Second gear 123 Third gear 124 Fourth gear 125 Fifth gear 126, 131 Gear support shaft 127 First bearing 128 also serving as a motor holder Third Bearing 129 Second bearing 134 Rotating positioning pin (positioning member)
135 Power Transmission Path 150 Imaging System Storage

Claims (6)

An image sensor incorporated in the distal end of the endoscope scope;
An objective optical system provided in front of the image sensor;
A cam member coupled to a moving lens that moves along the optical axis of the objective optical system;
A camshaft that is provided along a direction along the optical axis and moves the moving lens in a direction along the optical axis via the cam member by rotating around the direction along the optical axis as a rotation axis;
A gear portion that is integrally connected to an end portion of the cam shaft and is driven to rotate, thereby rotating the cam shaft;
A motor disposed coaxially with the camshaft;
A gear support shaft provided in parallel between the output shaft of the motor and the optical axis;
An electronic endoscope apparatus comprising: a reduction gear mechanism disposed between an output shaft of the motor and the gear support shaft and between the gear support shaft and the gear portion. The electronic endoscope apparatus according to claim 1,
An electronic endoscope apparatus in which a bearing that supports one end of the gear support also serves as a motor holder of the motor, and the motor holder holds the output shaft of the motor and the gear support in parallel. The electronic endoscope apparatus according to claim 1 or 2,
The reduction gear mechanism is an electronic endoscope apparatus configured by combining a plurality of two-stage gears integrally formed with a large-diameter gear portion and a small-diameter gear portion. The electronic endoscope apparatus according to claim 3,
The reduction gear mechanism includes a first gear fixed to the output shaft, and a second gear comprising the two-stage gear that is rotatably attached to the gear support shaft and a large-diameter gear portion meshes with the first gear. And a third gear comprising the two-stage gear spaced apart from the output shaft and rotatably supported by a support shaft coaxial with the cam shaft and having a large-diameter gear portion meshing with the small-diameter gear portion of the second gear; And a fourth gear which is rotatably attached to the gear support shaft and has a fourth gear in which a large-diameter gear portion meshes with a small-diameter gear portion of the third gear and a small-diameter gear portion meshes with the gear portion of the cam shaft. Mirror device. The electronic endoscope apparatus according to claim 4,
A bearing portion that supports one end portion of the gear support shaft is attached to a housing that houses the cam shaft and the gear portion of the cam shaft, and the support shaft of the third gear is supported on the bearing portion. An electronic endoscope apparatus in which a bearing portion is attached and the two bearing portions are positioned with respect to the housing by a positioning member. The electronic endoscope apparatus according to claim 4 or 5, wherein
An electronic endoscope apparatus in which the first gear is constituted by a small-diameter gear portion of the two-stage gear, and the first gear, the second gear, and the third gear are formed by common parts.

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