JP4694316B2 - Light source device for electronic endoscope and electronic endoscope device - Google Patents

Description

  The present invention relates to an electronic endoscope light source device and an electronic endoscope device using a plurality of aperture angle control rotating plates.

  In a conventional electronic endoscope, an endoscope recording apparatus disclosed in, for example, Japanese Patent Laid-Open No. 62-69222 has been proposed in order to perform appropriate light control. This apparatus has a rotary shutter provided with a rotation shaft capable of changing an inter-axis distance from an irradiation optical axis of an endoscope light source. This rotary shutter has a shape that causes a difference in peripheral speed at each position in the radial direction when it rotates or the aperture ratio changes, and this difference in peripheral speed is changed by changing the distance between the axes. Dimming is performed using it.

  In the device described in Japanese Patent Laid-Open No. 62-69222 described above, although dimming is possible, the configuration of the rotary shutter is complicated, and the distance between the rotary shutter and the irradiation optical axis of the endoscope light source is set. A mechanism to change is necessary, and manufacturing is costly and troublesome. Furthermore, to realize this configuration, the outer diameter of the rotary shutter must be several times the luminous flux of incident light, and the rotary shutter must be enlarged. Also, if the rotary shaft has an asymmetric shape with respect to its rotation axis in order to change the aperture ratio at each part of the rotary shutter, the center of rotation and the center of gravity will not match and the balance during rotation will be lost, and the illumination light will be emitted as desired. In addition, the rotary shutter and members disposed around the rotary shutter may be damaged.

  Based on the above problem awareness, the applicant of the present invention controls the opening angle of the light source and the rotation axis that are arranged in parallel with the optical axis of the light source and shields the illumination light incident from the light source or emits it toward the light guide. A rotation plate, and the opening angle control rotation plate is integrally rotatable and has a pair of coaxial opening angle control rotation plates each having a light shielding portion and an opening portion alternately in the rotation direction. Then, a light source device for an electronic endoscope that adjusts the amount of emitted light by changing the opening angle of the opening as the entire rotary shutter by rotating the pair of opening angle control rotating plates relative to each other has been proposed (special feature). Application No. 2005-26568).

The invention of this Japanese Patent Application No. 2005-26568 has a pair of planetary gear mechanisms, each planetary gear mechanism is rotationally driven by a phase difference motor separate from the chopper motor and the chopper motor, and each planetary gear mechanism is further driven. And a pair of opening angle control rotating plates are linked to each other. Therefore, when only the chopper motor is rotated, the pair of opening angle control rotating plates rotate at the same rotation speed, and the opening angle of the opening is kept constant. On the other hand, when both the chopper motor and the phase difference motor are rotated, a difference occurs in the rotation speed between the pair of opening angle control rotating plates, and the pair of opening angle control rotating plates rotate while changing the opening angle of the opening.
JP-A-62-69222 Japanese Patent Publication No. 7-85132

  In the invention of Japanese Patent Application No. 2005-26568, the minimum angle of the opening angle formed between the openings of the pair of opening angle control rotating plates is set to 0 °. Accordingly, when the pair of opening angle control rotating plates are relatively rotated until the opening angle becomes 0 °, the gap between the openings is eliminated, and the illumination light is completely blocked by the pair of opening angle control rotating plates.

  However, backlash exists between the gears constituting the planetary gear mechanism and between the output gear of the chopper motor (and the phase difference motor) and the planetary gear mechanism. For this reason, when the chopper motor (and the phase difference motor) is rotated with the opening angle being 0 ° to try to gradually increase the opening angle, a pair of apertures are opened immediately after the chopper motor (and the phase difference motor) is started. The angle-controlled rotating plate may not perform a desired operation (the rotation angle of the motor is not proportional to the opening angle). The sense of the operator (human) is that when the aperture angle is small compared to when the aperture angle is large, the increase / decrease range of the amount of illumination light with respect to the aperture angle change is large (high sensitivity), so the aperture angle is 0 °. Sometimes it is not preferable for the operator that the pair of opening angle control rotating plates do not perform a desired operation.

  The present invention relates to a light source device for an electronic endoscope that uses a planetary gear mechanism to perform rotation control of a pair of opening angle control rotating plates, and the opening angle between the openings of the pair of opening angle control rotating plates is a minimum opening angle. In this case, the surgeon obtains an electronic endoscope light source device and an electronic endoscope device that are not easily affected by backlash between the planetary gear mechanism gears or between the motor output gear and the planetary gear mechanism. For the purpose.

  A light source device for an electronic endoscope according to the present invention includes a light source, a rotary shutter whose rotation axis is arranged in parallel to the optical axis of the light source, and shields illumination light incident from the light source or emits it toward a light guide. The rotary shutter has a pair of coaxial opening angle control rotating plates that are capable of selecting relative rotation and integral rotation, each having a light shielding portion and an opening portion alternately in the rotation direction. A rotary light source device for an electronic endoscope that adjusts the amount of emitted light by rotating the aperture angle control rotating plate relative to each other so as to change and integrally rotate the opening angle of the opening as the entire rotary shutter. A first planetary gear having a first internal gear coaxial with the rotation shaft of the first planetary gear, a first sun gear coaxial with the first internal gear, and a first planetary gear meshing simultaneously with the first internal gear and the first sun gear. Gear mechanism A second internal gear coaxial with the rotary shaft of the rotary shutter and having the same specifications as the first internal gear, a second sun gear coaxial with the second internal gear and having the same specifications as the first sun gear, and the second A second planetary gear mechanism having a second planetary gear of the same specification as the first planetary gear meshing simultaneously with the internal gear and the second sun gear; and the first and second planetary gears with the first and second internal gears A carrier that is held in the same phase position with respect to the gear and that freely supports the relative rotation of the first and second planetary gears, and that can freely rotate about the rotation axis of the rotary shutter. One of the first sun gear and the first internal gear of one planetary gear mechanism is fixed and the other sun gear of the second planetary gear mechanism is driven to rotate together with one opening angle control rotating plate. And one of the second internal gears is driven by a phase difference motor together with the other opening angle control rotating plate, A mechanical stopper is provided between the pair of opening angle control rotating plates to limit the minimum opening angle of the opening angle formed between the openings of the pair of opening angle control rotating plates to a predetermined angle greater than 0 °. It is characterized by that.

  When the phase difference of the angle θ ° occurs between the pair of opening angle control rotating plates due to the total backlash existing between the gears, the minimum opening angle θmin is set to 0 ° <θmin ° <θ °. It is practical to set so that

  For example, the first internal gear can be fixed, the motor can drive the first sun gear and one opening angle control rotating plate, and the phase difference motor can drive the second internal gear.

  Further, even if the first sun gear is fixed, the motor rotates the first internal gear and one opening angle control rotating plate together, and the phase difference motor rotates the second sun gear. Good.

  According to another aspect, a light source device for an electronic endoscope according to the present invention has a light source and a rotation axis arranged in parallel to the optical axis of the light source, and shields illumination light incident from the light source or to a light guide. A rotary shutter that emits light, and the rotary shutter can be selected by selecting relative rotation or integral rotation, each of which has a pair of coaxial opening angle controlled rotations each having a light shielding portion and an opening portion alternately in the rotation direction. A light source for an electronic endoscope that adjusts the amount of emitted light by rotating the pair of opening angle control rotating plates relative to each other to change the opening angle of the opening as the whole rotary shutter and integrally rotating the same; A first internal gear coaxial with the rotary shaft of the rotary shutter, a first sun gear coaxial with the first internal gear, and a first meshing simultaneously with the first internal gear and the first sun gear With planetary gear A first planetary gear mechanism; a second internal gear coaxial with the rotary shaft of the rotary shutter and having the same specifications as the first internal gear; a second sun coaxial with the second internal gear and having the same specifications as the first sun gear A second planetary gear mechanism having a second planetary gear of the same specification as the first planetary gear meshing simultaneously with the gear and the second internal gear and the second sun gear; and the first and second planetary gears, A carrier that is rotatable about a rotation axis of a rotary shutter, which is held in the same phase position with respect to the second internal gear and supports the relative rotation of the first and second planetary gears freely. The second internal gear is fixed, the second sun gear and one opening angle control rotating plate are rotated together, and the first sun gear and the other opening angle control rotating plate are rotated by a motor. Is driven, the first internal gear is driven by the phase difference motor, and a pair of opening angles is controlled. A mechanical stopper is provided between the rolling plates to limit the minimum opening angle of the opening angle formed between the openings of the pair of opening angle control rotating plates to a predetermined angle greater than 0 °. .

  Also in this aspect, when the phase difference of the angle θ ° occurs between the pair of opening angle control rotating plates due to the sum of the backlashes existing between the gears, the minimum opening angle θmin is set to 0 ° < It is practical to set so that θmin ° <θ °.

  In this aspect, it is preferable that the first internal gear is rotatably supported by the gear bearing.

  In any embodiment, the mechanical stopper includes, for example, a minimum opening angle defining recess formed in one opening angle control rotating plate and the minimum opening angle projecting from the other opening angle control rotating plate. A stopper pin that defines the minimum opening angle by engaging with the defining recess can be used.

  Further, by engaging the maximum opening angle defining recess formed in one opening angle control rotating plate and the maximum opening angle defining recess protruding from the other opening angle controlling rotating plate, the above opening angle is set. And a stopper pin that defines the maximum opening angle.

  An operation unit, an insertion unit extending from the operation unit and inserted into the observation target, a light guide inserted into the operation unit and the insertion unit, and a distal end thereof extending to the distal end of the insertion unit; and the light guide An electronic endoscope apparatus can be obtained by providing the light source device that provides illumination light to the light source device.

  According to the present invention, since the minimum opening angle between the pair of opening angle control rotating plates is limited to a predetermined angle larger than 0 ° by the mechanical stopper, the operator can set the opening angle as compared with the case where the minimum opening angle is set to 0 °. I feel the increase / decrease width of the illumination light quantity with respect to the change small (sensitivity decreases). Therefore, even if the pair of opening angle control rotating plates having the opening angle at the minimum opening angle are rotated in the direction in which the opening angle is increased, the surgeon can perform backlash between the gears of the planetary gear mechanism and the output gear of the motor. The sensory influence received from the backlash between the planetary gear mechanisms is smaller than before.

Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS.
As shown in FIG. 1, an electronic endoscope 1 according to the present embodiment includes an operation unit 11 held by an operator, an elongated and flexible insertion unit 12 extending from the operation unit 11, and an operation unit. 11 is provided with a universal tube 13 extending from 11, and a connector portion 14 connected to an end of the universal tube 13. A light guide (light guide fiber) 20 is disposed inside the operation unit 11, the insertion unit 12, the universal tube 13, and the connector unit 14, and the tip of the light guide 20 is provided at the tip of the insertion unit 12. It is connected to an illumination optical system (not shown), and the illumination optical system emits illumination light toward the outside of the electronic endoscope 1.
The connector portion 14 of the electronic endoscope 1 is connected to a light source device (video processor) 30. A lamp (light source) 31 is disposed in the case 33 of the light source device 30, and illumination light emitted from the lamp 31 enters the light guide 20 from the incident end face 20 a of the light guide 20, passes through the light guide 20. The light is emitted from the illumination optical system at the distal end of the insertion portion 12 to the outside of the electronic endoscope 1. Illumination light (reflected light) reflected by the observation site is incident on the insertion section 12 from the objective optical system 15 provided at the distal end of the insertion section 12 and is a CCD (CMOS image) built in the distal end section of the insertion section 12. It may be another type of image sensor such as a sensor) (see FIG. 2). All pixel data of the CCD 16 is processed by the image processing device 18, and an image based on the pixel data is displayed on a display device (display) 19.

  In addition to the lamp 31, the light source device 30 includes a rotary shutter 40 as a dimming device capable of dimming and blocking illumination light (31a is an optical axis) emitted from the lamp 31, and light emitted from the lamp 31. A condensing lens 34 that condenses and guides the light to the incident end surface 20a of the light guide 20 and a drive mechanism DM1 for driving the rotary shutter 40 are provided.

As shown in FIGS. 3 to 7, the rotary shutter 40 includes a first opening angle control rotating plate 41 and a second opening angle control rotating plate 42 having substantially the same outer shape.
The first opening angle control rotating plate 41 shown in FIGS. 3A and 4 is a flat plate member made of aluminum orthogonal to the optical axis 31a, and has a circular central portion 41a and a pair of continuous portions. A light shielding part 41e and a light shielding part 41f are provided. The central portion 41a is formed with a circular central hole 41b at the center thereof, and three protrusions 41g and 41t extend radially outward from the periphery at 120 ° intervals. The two protrusions 41g include a pair of side surfaces 41i and side surfaces 41j facing in the radial direction with the center 41h of the central portion 41a as the center (see FIG. 4). The adjacent side surfaces 41j of the two protrusions 41g are An angle of 90 ° is formed around the center 41h of the central portion 41a. Further, the two side surfaces 41j adjacent to each other of the two protrusions 41g have the same shape (substantially semicircular shape) minimum opening angle defining recess (mechanical stopper) at the same radial distance from the center 41h. 41k and a maximum opening angle defining recess 41m are provided.
The light-shielding part 41e and the light-shielding part 41f are symmetrical with respect to the center 41h, and each have a substantially sector shape with a central angle of 90 ° centered on the center 41h. Between the light shielding part 41e and the light shielding part 41f, openings 41c and 41d having a central angle of 90 ° centering on the center 41h are formed. As shown in FIG. 3, the linear distance from the center 41h to the outer peripheral edges of the light shielding part 41e and the light shielding part 41f (= the radius of the first opening angle control rotating plate 41) is R41.

On the other hand, the second opening angle control rotating plate 42 shown in FIG. 3B is a flat plate member made of aluminum orthogonal to the optical axis 31a, and includes a central disk portion 42a, a pair of light shielding portions 42e, and a light shielding portion. 42f. A cylinder whose axis is parallel to the optical axis 31a at a position away from the center 42h of the disk portion 42a by the same distance as the linear distance from the center 41h to the minimum opening angle defining recess 41k and the maximum opening angle defining recess 41m. A stopper pin (mechanical stopper) 42g having a shape and a stopper pin 42p are projected. The stopper pin 42g and the stopper pin 42p have the same shape, and their cross-sectional radii are smaller than the radii of the minimum opening angle defining recess 41k and the maximum opening angle defining recess 41m, and are substantially half of the stopper pin 42g and the stopper pin 42p. Can be fitted into the minimum opening angle defining recess 41k and the maximum opening angle defining recess 41m, respectively. The circumferential positions of the stopper pin 42g and the stopper pin 42p around the center 42h of the disk portion 42a are separated by α ° (5 ° in this embodiment). The light-shielding part 42e and the light-shielding part 42f are symmetrical with respect to the center 42h of the disk part 42a, and have a substantially sector shape with a central angle of 90 ° -α ° (= 85 °) centered on the center 42h. Between the light shielding portion 42f and the light shielding portion 42f, an opening portion 42c and an opening portion 42d having a central angle 90 ° + α ° (= 95 °) with the center 42h as the center are formed. As shown in FIG. 3B, the linear distance from the center 42h to the outer peripheries of the light shielding part 42e and the light shielding part 42f (= the radius of the second opening angle control rotating plate 42) is R42 (<R41).
Here, the radii R41 and R42 are set to be equal to or greater than the diameter of the luminous flux of the illumination light incident on the rotary shutter 40 from the lamp 31. If this condition is satisfied, R41 = R42 may be satisfied, or R41 <R42 may be satisfied. In addition, the central angles of the openings and the light shielding portions of the illustrated first opening angle control rotating plate 41 and second opening angle control rotating plate 42 may be values other than those described above.

  As shown in FIG. 5, the center 41h of the first opening angle control rotating plate 41 and the center 42h of the second opening angle control rotating plate 42 are matched (overlapped), and the X axis (horizontal direction) and Y axis (vertical direction). Are arranged such that the light shielding part 41e and the light shielding part 41f are in the first quadrant and the third quadrant, respectively. Then, the second opening angle control rotating plate 42 is rotated counterclockwise with respect to the counterclockwise end surface of the first opening angle control rotating plate 41 (the rotating direction is the light condensing). The direction when the lamp 31 is viewed from the lens 34 is used as a reference, see the arrow A in Fig. 1 and Fig. 8. The same applies to the second and third embodiments. A portion of the opening 41c and the opening 41d is shielded by the light shielding part 42e and the light shielding part 42f. As a result, the openings 40c and 40d formed by the rotary shutter 40 are symmetrical with respect to the center 41h and the center 42h and have a substantially fan shape with a center angle (opening angle) θ of (90−β) °. As shown in FIGS. 6 and 7, the opening angle θ is set to 5 ° to 90 ° by rotating the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42 relative to each other (5 ° is the minimum opening). The angle can be changed in the range of 90 ° (maximum opening angle). When θ shown in FIG. 6 is 5 °, the stopper pin 42g engages with the minimum opening angle defining recess 41k, so that the second opening angle control rotating plate 42 is further counteracted against the first opening angle control rotating plate 41. Relative rotation in the clockwise direction is prevented. On the other hand, when [theta] shown in FIG. 7 is 90 [deg.], The stopper pin 42p engages with the maximum opening angle defining recess 41m, so that the second opening angle control rotating plate 42 is in contact with the first opening angle control rotating plate 41. The above relative rotation in the clockwise direction is prevented.

Next, the drive mechanism DM1 will be described with reference to FIGS.
A drive shaft (rotating shaft) 50 orthogonal to the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42 (parallel to the optical axis 31a) is at the center of the first opening angle control rotating plate 41. The center hole 41b is drilled so as to be relatively rotatable (the center 41h and the center 42h are located on the extended line of the drive shaft 50), and one end of the center hole 41b extends to the center 42h of the second opening angle control rotating plate 42. It is fixed. A drive shaft of a chopper motor (motor) M1 fixed to the light source device 30 is concentrically fixed to the other end of the drive shaft 50 (concentric when viewed in the direction of arrow A. Hereinafter, it is called concentric. When the chopper motor M1 is driven, the drive shaft 50 rotates about its axis. Around the drive shaft 50, an internal gear (first internal gear) 51 that is concentric with the drive shaft 50 and is fixed to the light source device 30 is positioned (internal teeth). In order to show that the gear 51 is a fixed member, the internal gear 51 is hatched in FIG. 8). The internal gear 51 has 60 inner peripheral teeth 52 of equal pitch on the entire inner peripheral surface (illustration of a specific shape of the inner peripheral teeth 52 is omitted for the sake of convenience. The same applies to the teeth of the gear member). A central portion of a circular first sun gear 53 having a smaller diameter than the internal gear 51 and located on the same plane as the internal gear 51 is coaxially fixed to the drive shaft 50. 24 outer peripheral teeth 54 are formed at equal pitch intervals on the entire outer peripheral surface of the first sun gear 53. Furthermore, between the internal gear 51 and the first sun gear 53, two first planetary gears 55 having the same diameter as the first sun gear 53 and having 18 outer peripheral teeth 56 at equal pitch intervals, The outer peripheral teeth 56 of both first planetary gears 55 mesh with the inner peripheral teeth 52 of the internal gear 51 and the outer peripheral teeth 54 of the first sun gear 53, respectively. ing. A circular mounting hole 55a is formed in the center of each of the two first planetary gears 55, and each mounting hole 55a has a portion near the end of the driven shaft 57 parallel to the drive shaft 50 on the chopper motor M1 side. Is fitted and fixed. Between the internal gear 51, the first sun gear 53, and the first planetary gear 55 and the chopper motor M1, a first carrier (carrier) 58 facing the radial direction of the internal gear 51 is located. A drive shaft 50 passes through a center hole 59 formed in the center of the carrier 58 so as to be relatively rotatable. Further, the both ends of the first carrier 58 are provided with engagement holes 60 into which the ends of the driven shafts 57 on the chopper motor M1 side are fitted so as to be relatively rotatable.
The internal gear 51, the first sun gear 53, and the first planetary gear 55 constitute a first planetary gear mechanism GM1.

The ends of the driven shafts 57 on the first opening angle control rotating plate 41 side are rotated relative to engagement holes 62 formed at both ends of a second carrier (carrier) 61 having substantially the same shape as the first carrier 58. It is possible to fit. A mounting hole 63 is formed in the center of the second carrier 61, and the mounting hole 63 is arranged around the drive shaft 50 so as to be rotatable with respect to the drive shaft 50. Are penetrated so as to be relatively rotatable. The end surface of the rotating cylinder 64 on the chopper motor M <b> 1 side has the same diameter as the first sun gear 53 and the outer peripheral teeth 65 having the same specifications as the first sun gear 53 and is concentric with the first sun gear 53. The center part of the sun gear 66 is fixed concentrically, and the drive shaft 50 passes through the center hole 67 formed in the center part of the second sun gear 66. Furthermore, the end of the rotating cylinder 64 on the second opening angle control rotating plate 42 side is fitted and fixed to the center hole 41b of the first opening angle control rotating plate 41, and the inner space of the rotating cylinder 64 and the center hole 41b are fixed. Are communicating. On the outer peripheral side of the second sun gear 66, an inner and outer both-teeth gear (second inner gear) 68 that is concentric with the second sun gear 66 and located on the same plane as the second sun gear 66 is rotatable. Inner peripheral teeth 69 having the same specifications as the inner gear 51 are formed on the inner peripheral surface of the inner and outer both tooth gears 68. Further, between the second sun gear 66 and the inner and outer tooth gears 68, two second planetary gears having the same diameter as the first planetary gear 55 and having outer peripheral teeth 71 having the same specifications as the first planetary gear 55 are provided. 70 is located symmetrically with respect to the second sun gear 66. A driven shaft 57 is rotatably fitted in the center hole 70 a of the second planetary gear 70, and the outer peripheral teeth 71 of both the second planetary gears 70 and the inner peripheral teeth 69 of the inner and outer both toothed gears 68 are the same as the second peripheral gears 68. The outer peripheral teeth 65 of the sun gear 66 are engaged with each other. Further, outer peripheral teeth 72 having the same pitch are formed on the entire outer peripheral surface of the inner and outer both gears 68, and the outer peripheral teeth 74 formed on the entire outer peripheral surface of the drive gear 73 mesh with the outer peripheral teeth 72. ing. The drive gear 73 is rotated around the rotation shaft 75 by a phase difference motor M2 fixed to the light source device 30.
The second planetary gear mechanism GM2 is configured by the second sun gear 66, the inner and outer both teeth gear 68, and the second planetary gear 70.

  As shown in FIG. 2, harnesses (wirings) M1a and M2a extend from the main body of the chopper motor M1 and the main body of the phase difference motor M2, and the harnesses M1a and M2a are CPUs (central processing units) built in the light source device 30. It is electrically connected to a controller (control means) 35 constituted by a processing device. The controller 35 controls the chopper motor M1 and the phase difference motor M2, and calculates the luminance value of the subject based on the luminance signal from the CCD 16. Further, the light source device 30 is provided with an automatic dimming switch S1, a chopper motor control button S2, and a phase difference motor control button S3, all of which are electrically connected to the controller 35.

Next, operations of the drive mechanism DM1 and the rotary shutter 40 will be described with reference mainly to FIGS.
The driving force of the chopper motor M1 and the phase difference motor M2 is transmitted to each component of the driving mechanism DM1, but in order to facilitate understanding of the operation of the driving mechanism DM1, only the driving force of the chopper motor M1 is considered first. .
When the chopper motor M1 is rotated in the clockwise direction, the drive shaft 50 and the first sun gear 53 are rotated in the clockwise direction at the speed SP1. Then, the two first planetary gears 55 rotate counterclockwise around the driven shaft 57 and revolve clockwise around the drive shaft 50. Further, the second carrier 61 is synchronized with the first carrier 58 by the driven shaft 57 (always located at the same phase position with respect to the internal gear 51 and the internal and external gears 68) and rotates clockwise. The two second planetary gears 70 rotate counterclockwise around the driven shaft 57 and revolve clockwise around the drive shaft 50. At this time, the rotation speed and revolution speed of the second planetary gear 70 are the same as those of the first planetary gear 55. Therefore, the second sun gear 66 rotates in the clockwise direction at the speed SP1.

Thus, the second sun gear 66 obtains the same rotational speed SP1 as the first sun gear 53 from the chopper motor M1, but when the driving force of the phase difference motor M2 is transmitted to the second sun gear 66, the second sun gear 66 The gear 66 rotates at a speed different from that of SP1.
That is, when the phase difference motor M2 rotates in the opposite direction to the chopper motor M1 and the inner and outer toothed gears 68 rotate clockwise, the rotational force of the inner and outer toothed gears 68 is transmitted to the second planetary gear 70, and the second planetary gears 70 are transmitted. The counterclockwise rotation speed of the gear 70 becomes faster than when the gear 70 rotates only with the driving force from the chopper motor M1. Accordingly, the second sun gear 66 meshing with the second planetary gear 70 rotates in the clockwise direction at a rotational speed SP2 faster than the rotational speed SP1 of the first sun gear 53.
On the other hand, when the phase difference motor M2 is rotated in the same direction as the chopper motor M1, the inner and outer toothed gears 68 are rotated counterclockwise, and the counterclockwise rotation speed of the second planetary gear 70 is the driving force of the chopper motor M1. Therefore, the clockwise rotation speed of the second sun gear 66 is SP3 slower than SP1.

As described above, when a difference occurs between the rotation speed SP2 (SP3) of the second sun gear 66 and the rotation speed SP1 of the first sun gear 53, the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42. Therefore, the opening angle θ between the opening 40c and the opening 40d gradually changes within a range of 5 ° to 90 °.
Then, the second opening angle control rotating plate 42 rotates relative to the first opening angle control rotating plate 41 counterclockwise, the opening angle θ becomes 5 ° as shown in FIG. 6, and the stopper pin 42g is the minimum opening. Engagement with the angle defining recess 41k restricts the opening angle θ from being further reduced. On the other hand, the second opening angle control rotating plate 42 rotates relative to the first opening angle control rotating plate 41 in the clockwise direction, the opening angle θ becomes 90 ° as shown in FIG. 7, and the stopper pin 42p has the maximum opening angle. Engaging with the defining recess 41m restricts the opening angle θ from becoming larger.

The light source device 30 of this embodiment can perform automatic light control and manual light control using the drive mechanism DM1 that performs such an operation. In automatic light control and manual light control, the insertion part 12 of the electronic endoscope 1 is inserted into a patient body to be observed, the observation part is illuminated with illumination light from the lamp 31, and the controller 35 emits a luminance signal from the CCD 16. Based on the above, it is performed in a state where the brightness of the observation site is always detected.
When the automatic dimming switch S1 is turned on, the controller 35 that has received a command from the automatic dimming switch S1 automatically controls the rotation speed and direction of the chopper motor M1 and the phase difference motor M2 based on the luminance signal from the CCD 16. The opening angle θ between the opening 40c and the opening 40d is changed between 5 ° and 90 °. Then, the amount of illumination light that passes through the rotary shutter 40 changes, and the luminance value of the observation site always becomes a desired value.

Manual dimming is performed by manually operating the chopper motor control button S2 and the phase difference motor control button S3 after turning off the automatic dimming switch.
In this case, first, the chopper motor M1 and the phase difference motor M2 are rotated by the chopper motor control button S2 and the phase difference motor control button S3. When the opening angle θ between the opening 40c and the opening 40d reaches a desired value, the phase difference motor M2 is stopped by the phase difference motor control button S3, and the opening angle θ between the opening 40c and the opening 40d is set to the desired value. Hold on. Thus, when the driving force from the phase difference motor M2 to the second sun gear 66 is cut off and the second sun gear 66 is rotated only by the chopper motor M1, the first opening angle control rotating plate 41 and the second opening angle control are performed. The rotating plate 42 rotates in the same direction at the same speed while maintaining a desired opening angle θ. Further, by operating the chopper motor control button S2 and the phase difference motor control button S3, the rotation speed of the chopper motor M1 and the phase difference motor M2 can be adjusted, so that the operator manually controls the amount of illumination light to be sent to the light guide 20. Can be adjusted freely.

  According to the present embodiment described above, the minimum angle of the opening angle θ of the rotary shutter 40 is mechanically limited to 5 ° by the minimum opening angle defining recess 41k and the stopper pin 42g. In a state where the rotary shutter 40 stops rotating with the opening angle θ = 5 ° (minimum opening angle) (or the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42 stop relative rotation), If the opening angle θ is gradually increased by the driving force of the driving mechanism DM1, the gears constituting the first planetary gear mechanism GM1 and the second planetary gear mechanism GM2 when the chopper motor M1 (and the phase difference motor M2) starts rotating. Due to the backlash between each other and the backlash between the outer peripheral teeth 72 and the outer peripheral teeth 74, the opening angle θ may not increase immediately (the rotation angle of the motor and the size of the opening angle are not proportional). However, compared to the conventional case where the minimum angle of the opening angle θ is set to 0 °, the increase / decrease range of the amount of illumination light felt by the operator is small (the sensitivity is low) when the angle is 5 °. Can be reduced compared to the case where the minimum opening angle is 0 °.

  Further, the opening angle θ of the rotary shutter 40 is limited to 5 ° to 90 ° by a mechanical stopper mechanism (a minimum opening angle defining recess 41k, a maximum opening angle defining recess 41m, a stopper pin 42g, and a stopper pin 42p). Therefore, it is not necessary to control the chopper motor M1 and the phase difference motor M2 so accurately as compared with the prior art. That is, conventionally, a sensor for detecting the relative rotation angle (phase difference) between the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42 is used, and the driving means (motor) is based on the detection result of this sensor. However, in order to prevent overshoot (overshoot) and to accurately set the opening angle θ to 5 ° or 90 °, it is necessary to control the driving means accurately.

  Further, the main bodies of the chopper motor M1 and the phase difference motor M2 of the drive mechanism DM1 do not rotate, and the respective harnesses (wirings) M1a and M2a are not twisted or bent as the chopper motor M1 and the phase difference motor M2 rotate. Therefore, it is not necessary to perform special processing on the harnesses M1a and M2a.

Next, a second embodiment of the present invention will be described with reference mainly to FIGS. Note that only the drive mechanism DM2 is different from the first embodiment, and the same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
Around the drive shaft 50 and the drive shaft of the chopper motor M1, a cylindrical fixed bearing AS that is concentric with these and opens at both ends is provided in a state of being fixed to the light source device 30. The inner and outer both teeth gear (first inner gear) 80 has a substantially cylindrical shape, and a cylindrical fitting portion 80a concentric with the drive shaft 50 is integrally formed at the center of the chopper motor M1 side surface. Has been. The cylindrical fitting portion 80a is fitted to the fixed bearing AS so as to be relatively rotatable around the drive shaft 50. The inner and outer both gears 80 have the same diameter as the inner gear 51, and a circular opening concentric with the drive shaft 50 is formed on the end face on the first opening angle control rotating plate 41 side. An inner peripheral tooth 81 having the same specifications as the inner peripheral tooth 52 is formed on the entire circumference of the circular opening, and the outer peripheral teeth 72 and the entire outer peripheral surface of the end portion on the first opening angle control rotating plate 41 side are formed. The outer peripheral teeth 82 having the same specifications are formed. The outer peripheral teeth 82 mesh with the outer peripheral teeth 74 of a drive gear 73 that is rotationally driven by a phase difference motor M2 fixed to the light source device 30.
The internal gear (second internal gear) 83 has the same diameter as the internal and external gears 68, and the internal peripheral teeth 84 having the same specifications as the internal peripheral teeth 69 are formed on the entire internal peripheral surface thereof. Concentric with the gear 66. The internal gear 83 is fixed to the light source device 30 and cannot be rotated (in order to show that the internal gear 83 is a fixed member, the internal gear 83 is hatched in FIG. 10).
In the present embodiment, the first planetary gear mechanism GM1 is constituted by the inner and outer both teeth gear 80, the first sun gear 53, and the first planetary gear 55, and the second sun gear 66, the inner and outer both teeth gear 83, and the first planetary gear mechanism GM1. The second planetary gear mechanism GM2 is constituted by the two planetary gears 70.

Next, the rotation operation of the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42 will be described.
First, a case where the automatic dimming switch S1 is turned on will be described.
When the controller 35 rotates the chopper motor M1 based on the luminance signal from the CCD 16, the rotational force of the chopper motor M1 is transmitted to the second sun gear 66 through the same path as in the first embodiment. The second sun gear 66 and the second opening angle control rotating plate 42 are all rotated at the speed of SP1. When the controller 35 rotates the phase difference motor M2 in the direction opposite to the chopper motor M1 based on the luminance signal from the CCD 16, the inner and outer tooth gears 80 rotate in the direction opposite to the rotation direction of the first planetary gear 55, Since the rotation speed of the first planetary gear 55 is increased, the rotation speed of the first sun gear 53, the drive shaft 50, and the first opening angle control rotating plate 41 is higher than the rotation speed SP1 of the second sun gear 66. Become. Then, a rotational speed difference is generated between the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42, and the opening angle θ between the opening 40c and the opening 40d changes in the range of 5 ° to 90 °. Therefore, the amount of illumination light that passes through the rotary shutter 40 automatically changes, and the observation site always has a desired luminance value.
On the other hand, when the controller 35 rotates the phase difference motor M2 in the same direction as the chopper motor M1 based on the luminance signal from the CCD 16, the rotation direction of the inner and outer toothed gears 80 and the rotation direction of the first planetary gear 55 become the same. The rotation speed of the first planetary gear 55 is slower than when the phase difference motor M2 is stopped, and the rotation speed SP3 of the first sun gear 53, the drive shaft 50, and the first opening angle control rotating plate 41 is slower than SP1. Become. Then, a rotational speed difference is generated between the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42, and the opening angle θ between the opening 40c and the opening 40d changes in the range of 5 ° to 90 °. Therefore, the amount of illumination light that passes through the rotary shutter 40 automatically changes, and the observation site always has a desired luminance value.

On the other hand, if the chopper motor control button S2 and the phase difference motor control button S3 are operated after turning off the automatic dimming switch, manual dimming can be performed also in this embodiment.
First, the chopper motor control button S2 and the phase difference motor control button S3 are manually operated to rotate the chopper motor M1 and the phase difference motor M2. When the opening angle θ of the opening 40c and the opening 40d reaches a desired value, the position is changed. The phase difference motor control button S3 is operated to stop the phase difference motor M2, and then the first sun gear 53 is rotated only by the chopper motor M1. As described above, when the phase difference motor M2 stops and both the inner and outer toothed gears 80 are fixed and the drive mechanism DM2 is operated only by the driving force of the chopper motor M1, the first sun gear 53 and the second sun gear as described above. 66 rotates in the same direction at the same speed SP1, and the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42 rotate in the same direction while maintaining a desired opening angle θ. Therefore, the surgeon can manually adjust the amount of illumination light sent to the light guide 20 manually.

  Also in this embodiment, the same effect as that of the first embodiment can be obtained, and furthermore, the cylindrical fitting portion 80a of the both internal and external gears 80 is rotatably supported by the fixed bearing AS. The weight of the tooth gear 80 is not transmitted to the drive shaft 50. Accordingly, the load applied to the drive shaft 50 and the chopper motor M1 can be reduced as compared with the drive mechanism DM1 of the first embodiment in which the weights of the inner and outer tooth gears 68 are transmitted to the drive shaft 50 via the second planetary gear 70.

Finally, a third embodiment of the present invention will be described with reference mainly to FIGS. The same members as those in the first embodiment are designated by the same reference numerals, and detailed description thereof is omitted.
The drive mechanism DM3 of this embodiment has the following structure.
A drive shaft (rotating shaft) 90 that is integrally projected at the center of the first opening angle control rotating plate 41 and is orthogonal to the first opening angle control rotating plate 41 (parallel to the optical axis 31a) is a light source. It is rotated around its axis by a chopper motor M1 fixed to the device 30. The first opening angle control rotating plate 41 is opposed to the second opening angle control rotating plate 42 (the surface on the opposite side of the driving shaft 90), and is substantially cylindrical first inner and outer teeth concentric with the driving shaft 90. A gear (first internal gear) 91 is protruded. A circular opening concentric with the drive shaft 90 is formed on the end face on the second opening angle control rotary plate 42 side of the first inner / outer gear gear 91, and the entire circumference of the circular opening is the same as the inner peripheral tooth 52. The inner peripheral teeth 92 of the specification are formed. The first sun gear 53 fixed to the light source device 30 is located at the center of the circular opening so as to be concentric with the inner peripheral teeth 92 (the first sun gear 53 is a fixing member). In order to show that, the first sun gear 53 is hatched in FIG. 13). Unlike the first sun gear 53 of the first embodiment, the first sun gear 53 of the present embodiment does not have a hole at the center thereof. The outer peripheral teeth 54 of the first sun gear 53 and the inner peripheral teeth 92 of the first inner and outer both gears 91 are engaged with the outer peripheral teeth 56 of the two first planetary gears 55, respectively. Is located at a symmetrical position with respect to the first sun gear 53. End portions of the driven shaft 57 penetrating (fixed) through the two first planetary gears 55 on the chopper motor M1 side are connected by a first carrier 58. Unlike the first carrier 58 of the first embodiment, the first carrier 58 of the present embodiment does not include the center hole 59.

A circular through hole 94 is formed at the center of the second opening angle control rotating plate 42, and a drive shaft (parallel to the optical axis 31a) coaxial with the drive shaft 90 passes through the through hole 94. A phase difference motor M2 fixed to the light source device 30 is connected to the end of the rotary shaft 95 opposite to the chopper motor M1, and the drive shaft 95 is rotated around its axis by the phase difference motor M2. To be rotated. The end of the drive shaft 95 opposite to the phase difference motor M <b> 2 is fitted and fixed in a mounting hole 66 a formed in the center of the second sun gear 66. On the surface of the second opening angle control rotating plate 42 on the first opening angle control rotating plate 41 side, a substantially cylindrical second inner / outer two-tooth gear (second inner gear) concentric with the first inner / outer both-teeth gear 91 is provided. ) 96 is projected. A circular opening concentric with the drive shaft 95 is formed on the end face of the second inner and outer toothed gear 96 on the first opening angle control rotating plate 41 side, and the entire circumference of the circular opening is the same as the inner peripheral tooth 92. Inner peripheral teeth 97 having specifications are formed. The outer peripheral teeth 65 of the two second planetary gears 70 mesh with the outer peripheral teeth 65 of the second sun gear 66 and the inner peripheral teeth 97 of the second inner and outer toothed gears 96, respectively. It is located at a symmetrical position with respect to the second sun gear 66. The driven shaft 57 passes through the center hole 70a of the two second planetary gears 70 so as to be relatively rotatable, and the end portions of the two driven shafts 57 on the phase difference motor M2 side are connected by the second carrier 61. . A circular through hole 98 through which the drive shaft 95 penetrates in a relatively rotatable manner is formed in the center of the second carrier 61.
In the present embodiment, the first planetary gear mechanism GM1 is configured by the first inner / outer both-tooth gear 91, the first sun gear 53, and the first planetary gear 55, and the second sun gear 66, the second inner / outer both-tooth gear. 96 and the second planetary gear 70 constitute a second planetary gear mechanism GM2.

Next, the operation of the drive mechanism DM3 and the rotation operations of the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42 will be described.
First, a case where the automatic dimming switch S1 is turned on will be described.
When the controller 35 rotates the chopper motor M <b> 1 based on the luminance signal from the CCD 16, the first inner / outer both-teeth gear 91 rotates at the speed SP <b> 1, and the first planetary gear 55 changes the rotation direction of the first inner / outer both-teeth gear 91. It revolves in the same direction as the first internal and external toothed gear 91 while rotating in the reverse direction. Then, the second planetary gear 70 synchronized with the first planetary gear 55 by the driven shaft 57 and the second carrier 61 rotates and revolves at the same speed in the same direction as the first planetary gear 55, The both-tooth gear 96 rotates in the same direction as the first inner and outer both-tooth gear 91 at a speed SP1.
If the controller 35 rotates the phase difference motor M2 in the same direction as the chopper motor M1 based on the luminance signal from the CCD 16 with the chopper motor M1 rotated, the second sun gear 66 rotates in the same direction. The rotation speed of the planetary gear 70 is increased. Accordingly, the second internal / external double gear 96 rotates in the same direction as the first internal / external gear 91 at a speed SP2 faster than SP1. Then, a rotational speed difference is generated between the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42, and the opening angle θ between the opening 40c and the opening 40d changes in the range of 5 ° to 90 °. Therefore, the amount of illumination light that passes through the rotary shutter 40 automatically changes, and the observation site always has a desired luminance value.
On the other hand, when the controller 35 rotates the phase difference motor M2 in the direction opposite to the chopper motor M1 based on the luminance signal from the CCD 16, and rotates the second sun gear 66 in the same direction as the rotation direction of the second planetary gear 70, The rotation speed of the second planetary gear 70 becomes slow. As a result, the second inner and outer tooth gears 96 rotate in the same direction as the first inner and outer tooth gears 91 at a speed SP3 slower than SP1. Then, a rotational speed difference is generated between the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42, and the opening angle θ between the opening 40c and the opening 40d changes in the range of 5 ° to 90 °. Therefore, the amount of illumination light that passes through the rotary shutter 40 automatically changes, and the observation site always has a desired luminance value.

On the other hand, if the chopper motor control button S2 and the phase difference motor control button S3 are operated after turning off the automatic dimming switch, manual dimming can be performed also in this embodiment.
First, the chopper motor control button S2 and the phase difference motor control button S3 are manually operated to rotate the chopper motor M1 and the phase difference motor M2, and the opening angles 41c and 41d, the opening portion 42c, and the opening angle θ of the opening portion 42d are desired. When the value is reached, the phase difference motor control button S3 is operated to stop the phase difference motor M2, and then the first inner / outer both teeth gear 91 and the second inner / outer teeth gear 96 are rotated only by the chopper motor M1. Thus, when the phase difference motor M2 is stopped and the second internal and external gears 96 are fixed, the first internal and external gears 91 and the second internal and external gears 96 rotate at the same speed in the same direction. The one opening angle control rotating plate 41 and the second opening angle control rotating plate 42 rotate while maintaining a desired opening angle θ. Therefore, the surgeon can manually adjust the amount of illumination light sent to the light guide 20 manually.
In the present embodiment described above, the same effect as that of the first embodiment can be obtained.

As described above, the present invention has been described with reference to each of the above-described embodiments, but the present invention is not limited to the first to third embodiments, and is improved or within the scope of the idea of the present invention or the idea of the present invention. It can be changed.
For example, although the minimum angle of the opening angle θ is set to 5 °, the minimum angle may be an angle other than 5 °, for example, 2 ° to 3 ° as long as the minimum angle is greater than 0 ° and close to 0 °. That is, if a phase difference of an angle θ ° occurs between the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42 due to the total backlash existing between the gears, The minimum angle θmin can be set in the range of 0 ° <θmin ° <θ °. Instead of the above θ, an angle θα (slightly larger than θ) corresponding to the relative movement resolution of the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42 may be used.
Further, the stopper pin 42g and the stopper pin 42p are provided on the first opening angle control rotating plate 41, and the minimum opening angle defining recess 41k and the maximum opening angle defining recess 41m are provided on the second opening angle control rotating plate 42. May be.
Further, in the first embodiment, the inner and outer both teeth gear 68 is substantially cylindrical like the inner and outer both teeth gear 80 of the second embodiment, and the cylindrical fitting portion is positioned on the outer peripheral side of the rotating cylinder 64. It may be supported rotatably by a fixed bearing AS (fixed to the light source device 30). In this way, the weight of the inner and outer tooth gears 68 is not transmitted to the drive shaft 50 via the second planetary gear 70, so the load on the drive shaft 50 and the chopper motor M1 can be reduced. In the third embodiment, the first opening angle control rotating plate 41 and the second opening angle control rotating plate 42 are integrally provided with a cylindrical fitting portion, and each cylindrical fitting portion is driven with the drive shaft 90. Each of the fixed bearings AS positioned on the outer peripheral side of the shaft 95 may be rotatably supported. In this way, the weights of the first internal and external double gear 91 and the second internal and external double gear 96 are not transmitted to the drive shaft 90 and the drive shaft 95 via the first planetary gear 55 and the second planetary gear 70. The load applied to the drive shaft 90, the drive shaft 95, the chopper motor M1, and the phase difference motor M2 can be reduced.

It is the schematic which shows the internal structure of the electronic endoscope which concerns on 1st embodiment of this invention. It is a block diagram which shows the structure of an electronic endoscope. (A) is a front view of a 1st opening angle control rotation board, (b) is a front view of a 2nd opening angle control rotation board. It is an enlarged front view of a 1st opening angle control rotating plate. It is a front view of an opening angle control rotating plate. It is a front view of an opening angle control rotation board when an opening angle is the minimum. It is a front view of an opening angle control rotating plate when the opening angle is maximum. It is a disassembled perspective view of a drive mechanism. It is a schematic diagram of a drive mechanism and its peripheral member. It is a disassembled perspective view of the drive mechanism of 2nd embodiment. It is a schematic diagram of a drive mechanism and its peripheral member. It is sectional drawing which follows the XII-XII arrow line of FIG. It is a disassembled perspective view of the drive mechanism of 3rd embodiment. It is a schematic diagram of a drive mechanism and its peripheral member.

Explanation of symbols

1 Electronic Endoscope 15 Objective Optical System 16 CCD (Imaging Device)
18 Image processing device 19 Display device 20 Light guide 30 Light source device 31 Lamp (light source)
31a Optical axis 35 Controller (control means)
40 Rotary shutter 41 First opening angle control rotating plate 41a Central portion 41b Center hole 41c 41d Opening portion 41e 41f Light shielding portion 41g 41t Projection portion 41h Center 41i 41j Side surface 41k Minimum opening angle defining recess (mechanical stopper)
41m Concave for maximum opening angle (mechanical stopper)
42 Second opening angle control rotating plate 42a Disk part 42b Center hole 42c 42d Opening part 42e 42f Light shielding part 42g 42p Stopper pin (mechanical stopper)
42h Center 50 Drive shaft (rotary shaft)
51 Internal gear (first internal gear)
52 Inner peripheral tooth 53 First sun gear 54 Outer peripheral tooth 55 First planetary gear 55a Mounting hole 56 Outer peripheral tooth 57 Drive shaft 58 First carrier (carrier)
59 Center hole 60 Engagement hole 61 Second carrier (carrier)
62 engagement hole 63 mounting hole 64 rotating cylinder 65 outer peripheral tooth 66 second sun gear 66a mounting hole 67 center hole 68 inner and outer both teeth gear (second inner gear)
69 Inner peripheral tooth 70 Second planetary gear 70a Center hole 71 Outer peripheral tooth 72 Outer peripheral tooth 73 Drive gear 74 Outer peripheral tooth 75 Central rotating shaft 80 Inner and outer both teeth gear (first inner gear)
80a Cylindrical fitting part 81 Inner peripheral tooth 82 Outer peripheral tooth 83 Internal gear (second internal gear)
84 Inner peripheral teeth 90 Drive shaft (rotary shaft)
91 1st internal and external gears (1st internal gear)
92 Inner peripheral teeth 94 Through hole 95 Drive shaft (rotary shaft)
96 Second internal / external gear (second internal gear)
97 Inner peripheral tooth 98 Through hole AS Fixed bearing DM1 DM2 DM3 Drive mechanism GM1 First planetary gear mechanism GM2 Second planetary gear mechanism M1 Chopper motor (motor)
M2 Phase difference motor S1 Automatic dimming switch S2 Chopper motor control button S3 Phase difference motor control button

Claims (10)

A light source, and a rotary shutter whose rotation axis is arranged in parallel with the optical axis of the light source and shields the illumination light incident from the light source or emits the light toward the light guide, the rotary shutter having a relative rotation Integral rotation can be selected, and each has a pair of coaxial opening angle control rotating plates provided with light shielding portions and openings alternately in the rotation direction, and the pair of opening angle control rotating plates are rotated relative to each other. A light source device for an electronic endoscope that adjusts the amount of emitted light by changing the opening angle of the opening as a whole rotary shutter and rotating it integrally.
A first internal gear that is coaxial with the rotary shaft of the rotary shutter, a first sun gear that is coaxial with the first internal gear, and a first planetary gear that meshes simultaneously with the first internal gear and the first sun gear. One planetary gear mechanism;
A second internal gear that is coaxial with the rotary shaft of the rotary shutter and has the same specifications as the first internal gear, a second sun gear that is coaxial with the second internal gear and has the same specifications as the first sun gear, and this second internal gear A second planetary gear mechanism having a second planetary gear of the same specification as the first planetary gear meshing simultaneously with the tooth gear and the second sun gear;
A rotary shutter that holds the first and second planetary gears in the same phase with respect to the first and second internal gears and supports the relative rotation of the first and second planetary gears freely. A carrier that is free to rotate around the axis of rotation;
Have
One of the first sun gear and the first internal gear of the first planetary gear mechanism is fixed, and the other is rotated by a motor together with one opening angle control rotating plate,
One of the second sun gear and the second internal gear of the second planetary gear mechanism is driven by a phase difference motor together with the other opening angle control rotating plate,
A mechanical stopper is provided between the pair of opening angle control rotating plates to limit the minimum opening angle of the opening angle formed between the openings of the pair of opening angle control rotating plates to a predetermined angle greater than 0 °. A light source device for an electronic endoscope characterized by the above. The light source device for an electronic endoscope according to claim 1,
When a phase difference of an angle θ ° occurs between the pair of opening angle control rotating plates due to the total backlash existing between the gears, the minimum opening angle θmin is
A light source device for an electronic endoscope set to satisfy 0 ° <θmin ° <θ °. The light source device for an electronic endoscope according to claim 1 or 2,
Fixing the first internal gear,
The motor drives the first sun gear and one opening angle control rotary plate,
A light source device for an electronic endoscope in which a phase difference motor drives a second internal gear. The light source device for an electronic endoscope according to claim 1 or 2,
Fixing the first sun gear,
The motor rotates the first internal gear and one opening angle control rotating plate together,
A light source device for an electronic endoscope in which the phase difference motor rotationally drives the second sun gear. A light source, and a rotary shutter whose rotation axis is arranged in parallel with the optical axis of the light source and shields the illumination light incident from the light source or emits the light toward the light guide, the rotary shutter having a relative rotation Integral rotation can be selected, and each has a pair of coaxial opening angle control rotating plates provided with light shielding portions and openings alternately in the rotation direction, and the pair of opening angle control rotating plates are rotated relative to each other. A light source device for an electronic endoscope that adjusts the amount of emitted light by changing the opening angle of the opening as a whole rotary shutter and rotating it integrally.
A first internal gear that is coaxial with the rotary shaft of the rotary shutter, a first sun gear that is coaxial with the first internal gear, and a first planetary gear that meshes simultaneously with the first internal gear and the first sun gear. One planetary gear mechanism;
A second internal gear that is coaxial with the rotary shaft of the rotary shutter and has the same specifications as the first internal gear, a second sun gear that is coaxial with the second internal gear and has the same specifications as the first sun gear, and this second internal gear A second planetary gear mechanism having a second planetary gear of the same specification as the first planetary gear meshing simultaneously with the tooth gear and the second sun gear;
A rotary shutter that holds the first and second planetary gears in the same phase with respect to the first and second internal gears and supports the relative rotation of the first and second planetary gears freely. A carrier that is free to rotate around the axis of rotation;
Have
Fix the second internal gear,
The second sun gear and one opening angle control rotating plate are rotated together,
The motor drives the first sun gear and the other opening angle control rotary plate,
The first internal gear is driven by the phase difference motor,
A mechanical stopper is provided between the pair of opening angle control rotating plates to limit the minimum opening angle of the opening angle formed between the openings of the pair of opening angle control rotating plates to a predetermined angle greater than 0 °. A light source device for an electronic endoscope characterized by the above. The light source device for an electronic endoscope according to claim 5,
When a phase difference of an angle θ ° occurs between the pair of opening angle control rotating plates due to the total backlash existing between the gears, the minimum opening angle θmin is
A light source device for an electronic endoscope set to satisfy 0 ° <θmin ° <θ °. The light source device for an electronic endoscope according to claim 5 or 6,
A light source device for an electronic endoscope in which a first internal gear is rotatably supported by a gear bearing. The light source device for an electronic endoscope according to any one of claims 1 to 7,
The mechanical stopper is
A recess for defining a minimum aperture angle formed on one aperture angle control rotating plate;
A light source device for an electronic endoscope, comprising: a stopper pin that defines the minimum opening angle by engaging with a recess for defining the minimum opening angle that is provided on the other opening angle control rotating plate. The light source device for an electronic endoscope according to claim 8, further comprising:
A recess for defining the maximum aperture angle formed on one aperture angle control rotating plate;
A light source device for an electronic endoscope, comprising: a stopper pin that defines a maximum opening angle of the opening angle by engaging with a recess for defining the maximum opening angle provided on the other opening angle control rotating plate. An electronic endoscope apparatus comprising the electronic endoscope light source device according to any one of claims 1 to 9,
An operation unit;
An insertion portion extending from the operation portion and inserted into the observation target;
A light guide that is inserted into the operation portion and the insertion portion, and whose tip extends to the tip of the insertion portion;
An electronic endoscope apparatus comprising: the light source device that provides illumination light to the light guide.

Images