JP2921681B2 - Endoscope - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope in which a focusing mechanism of an imaging lens is improved so as to meet a demand for a small diameter.

[Prior Art and Problems to be Solved by the Invention] For focusing of an imaging lens of an endoscope, for example, as described in JP-B-63-15567, a method of pulling a lens with a wire is used. It is known that the pulling of the wire is performed by driving a motor provided on the hand side.
Also, although not applied to an endoscope, the focusing of the lens, as described in JP-A-60-146207,
A lens in which a lens is directly driven by an electromagnetic motor is known.

However, in the former conventional technique, the endoscope is long and small in diameter, and it is difficult to transmit power due to play or friction generated in the wire, and the endoscope on the hand side where the motor is disposed. There is a disadvantage that the operation unit is large and heavy, and the operability is deteriorated.

On the other hand, when the latter conventional technology is applied to an endoscope, the electromagnetic motor has a complicated structure requiring multi-polar windings and brushes, so it is difficult to reduce the size, and the endoscope becomes larger in diameter. There is an inconvenience of doing so.

[Object of the Invention] The present invention has been made in view of these circumstances, and has a structure in which a lens is driven by an electrostatic actuator having a simple structure and an easy thickness reduction, so that a focusing driving mechanism is provided. It is an object of the present invention to provide an endoscope in which the diameter of the distal end portion can be reduced while incorporating therein.

[Means and Actions for Solving the Problems] An endoscope according to the present invention is an endoscope having an objective optical system at the end of the endoscope, wherein a focus adjusting lens for adjusting the focus of the objective optical system; While holding the focus adjustment lens, a rotor means having a first electrode group in which a plurality of electrodes are arranged at a predetermined pitch, and a rotor means in which a plurality of electrodes are arranged at a different pitch from the first electrode group A first electrode group of the rotor means and a second electrode group of the stator means, the stator means having two electrode groups and slidably holding the rotor means in the optical axis direction of the objective optical system. And voltage applying means for applying a voltage to the lens to move the focus adjustment lens held by the rotor means in the optical axis direction.

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

1 to 4 relate to a first embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of the endoscope, FIG. 2 is a sectional view of a distal end portion, FIG. 3 is a view taken along line III-III of FIG. 2, and FIG. 4 is an enlarged view of a diaphragm.

In these figures, reference numeral 1 denotes an endoscope device, 2 denotes a CCU (camera control unit) containing a light source device, and a monitor 3 is connected to the CCU 2.

The endoscope apparatus 1 includes an elongated and flexible insertion section 4 that can be inserted into a body cavity or the like, and a large-diameter operation section 5 that is connected to the base end of the insertion section 4. A universal cord 6 having a connector device 6a at the end extends from one side of the operation unit 5. Also, the above CCU2
Is provided with a connector receiver 2a to which the connector device 6a is engaged. The universal cord 6 is connected to the CCU 2 via the connector device 6a.

A light guide 7 is provided in the universal cord 6, and a light source device is provided in the CCU 2. Illumination light generated by the light source device is transmitted through the light guide 7. The information is transmitted to the endoscope apparatus 1 side. The light guide 7 in the universal cord 6 is connected to a light guide 7 provided in the insertion section 4, and the light guide 7 is extended to the distal end 8 of the insertion section 4, and It is fixed to an illumination through-hole 9 formed in the distal end portion 8. The illumination light from the light source device is radiated to a site to be observed, such as in a body cavity or a tube hole, through a light distribution lens 9a provided in the illumination through hole 9.

As shown in FIG. 2, the distal end portion 8 is provided with a distal end portion main body 11, and a cover 12a is mounted on the distal end side end surface of the distal end portion main body 11. The outer periphery is covered with an exterior rubber 12b.

Further, an observation through-hole 13 is formed through the tip end pair 11 and the cover 12a in parallel with the axis of the tip end body 11, and a holding member 14 is provided at the end of the observation through-hole 13. Mated. The holding member 14 is formed with a through-hole 14a having the same axis as the observation through-hole 13. The front lens 15 is provided at the distal end of the through-hole 14a, A stop 16 is fixed to the base end of 14a.
Accordingly, the amount of light incident on the observation through-hole 13 through the through-hole 14a is regulated.

As shown in FIG. 4, the diaphragm 16 is made of a sealing resin 17a.
A pair of transparent electrodes 18a and 18b are attached to the front and rear of the liquid crystal 17 in the optical axis direction. In addition, polarizing filters 21a and 21b are set on the side surfaces of the transparent electrodes 18a and 18b opposite to the liquid crystal 17 via glass plates 19a and 19b so that the directions of polarization are different from each other by 90 °.
Has been fixed.

A hole 18c having a central axis coinciding with the optical axis is formed in the transparent electrode 18b attached to the base end side of the liquid crystal 17, and a power supply 20a and a switch 20b are formed in both transparent electrodes 18a, 18b.
And the like. When the switch 20b is turned on, the portion of the liquid crystal 17 to which the transparent electrode 18b is attached becomes opaque, so that it becomes difficult for light to pass through the outer periphery of the liquid crystal 17,
The aperture 16 is stopped down.

Further, an electrostatic motor 22 as a driving means is disposed on the base end side of the observation through hole 13 with respect to the stop 16.

The electrostatic motor 22 is formed to be relatively long in the optical axis direction, and is fixed to the tip end body 11 by a stator 22a.
And a rotor 22b that is slidably in contact with the stator 22a and that can slide in parallel with the optical axis. A plurality of electrodes (not shown) are arranged on the opposing sides of the rotor 22b and the starter 22a at different pitches from each other.
Can be slid with respect to the stator 22a.

A holding member 23 extending in the optical axis direction is fixed to the rotor 22b. A hole 23a having a central axis coinciding with the optical axis is formed in the holding member 23.
In addition, a focus adjustment lens 24 is fitted, and when the rotor 22b is slid, the focus is adjusted by moving the lens 24 in the optical axis direction.

Further, a lens frame 25 is fixed on the base end side of the observation through hole 13 with respect to the lens 24 with a fixing screw 25a, and an optical system 26 including a plurality of lenses is fixed in the lens frame 25. ing.

Further, a solid-state imaging device 27 such as a CCD (Charge Coupled Device) is disposed at a base end side of the optical system 26 and at an image forming position by the optical system 26, and transmits light through the through hole 14a. Then, an optical image of the observed part whose light quantity is regulated by the diaphragm 16 is photoelectrically converted by the solid-state imaging device 27.

The solid-state imaging device 27 is connected to the CCU 2 via a signal line 27a provided in the insertion section 4 and the universal cord 6.
Is processed by the CCU 2 and output to the monitor 3 so that the image of the observed region can be observed through the screen 3a of the monitor 3. ing.

As shown in FIG. 1, the electrostatic motor 22 is connected via a signal line 29a to a CPU 29 disposed in the distal end portion 8, and the CPU 29 is connected to the operation unit 5 via a signal line 29b.
Are connected to the switches 5a and 5b provided in the controller 22. When the switches 5a and 5b are operated, the stator 22 is connected via the CPU 29.
By transmitting a signal to the electrostatic motor 22 via the signal line 29a so that a voltage is applied to the predetermined electrode of the rotor 22b and the rotor 22b, the rotor 22b is slid by an arbitrary amount.

Further, the CPU 29 is connected to an application device 20 for performing on / off operation of the switch 20b via another signal line 29c.

Then, when the lens 24 is moved to the base end side, that is, the short focus side by the movement of the rotor 22b, the application device 20 is operated according to this signal, and the switch 16 When the lens 24 is moved to the distal end side, that is, the long focal point side, while the light amount of the optical image is reduced and the depth of field is deepened, the switch 20b is turned off by a signal of this movement. The aperture 16 is opened to increase the amount of incident light.

When observing the observation site with the endoscope apparatus 1 having such a configuration, the universal cord 6 is connected to the CCU 2 via the connector device 6a, and the power of the CCU 2 is turned on. The insertion section 4 of the device 1 is inserted into a body cavity or a lumen. Then, illumination light generated by the light source device built in the CCU 2 is guided to the tip 8 by the light guide 7, and the light distribution lens provided in the illumination through hole 9 of the tip 8. Irradiation is performed on the site to be observed via 9a.

The optical image of the observed part enters the observation through-hole 13 through the front lens 15 fixed to the holding member 14, and the observation through-hole 13
The solid-state imaging device 27 is
Is imaged. Then, it is photoelectrically converted by the solid-state imaging device 27 and input into the CCU 2 via the signal line 29b.
The input signal line of the observed part is processed by the CCU 2 and output to the monitor 3, whereby the image of the observed part is displayed on the screen 3a of the monitor 3, and this screen is displayed.
Observation becomes possible at 3a.

By the way, the distance from the tip 8 to the region to be observed is generally continuously changed, and the focus adjustment is performed between when observing an adjacent region and when observing a distant region. May be required.

When observing a relatively close part, the user operates the switch 5a provided on the operation unit 5 with a finger or the like to obtain a CP.
A voltage is applied to the electrode of the electrostatic motor 22 via U29 to slide the rotor 22b of the electrostatic motor 22 toward the optical system 26, that is, the short focal point side, and the rotor 22b is connected to the rotor 22b via the holding member 23. The fixed lens 24 is moved to the short focal length side as shown by a broken line in FIG. Then, the focal point matches the portion close to the distal end portion 8, and an image of this portion is formed on the solid-state imaging device 27 and output to the monitor 3.

Further, the CPU 29 outputs a signal corresponding to the sliding direction of the rotor 22b to the application device 20 of the diaphragm 16 via the signal line 29c, and the switch 20b of the application device 20 is turned on.

Then, the voltage of the power supply 20a is applied to the transparent electrodes 18a, 18b, and the liquid crystal 17 at the portion sandwiched between the electrodes 18a, 18b becomes opaque, preventing light transmission. Meanwhile, the aperture
Since the hole 18c is formed in the center of the transparent member 18b attached to the base end side of 16, light transmission through the hole 18c is not hindered. The aperture 16 is thus stopped down, the amount of light incident through the observation through-hole 13 is regulated, and the brightness of the image near the distal end portion 8 where the amount of light tends to exceed is appropriate for observation. Become.

Further, when the stop 16 is stopped down, the depth of field is increased, which is advantageous for observation.

On the other hand, when observing a portion relatively far away from the distal end portion 8, the rotor 22 b and the lens 24 are moved to the distal end side, that is, the long focal point side by operating the switch 5 b provided on the operation section 5. Move. Then, a signal corresponding to the moving direction of the rotor 22b is applied via the signal line 29c to the application device 20.
The switch 20b is turned off by being input to the
When the liquid crystal 17 becomes transparent, the aperture 16 is opened, and the brightness of the image at a portion separated from the distal end portion 8 where the amount of light tends to be insufficient becomes suitable for observation.

Further, since the long focal length side has a large depth of focus, even if the depth of field becomes shallow due to the opening of the aperture, there is no problem in observation.

In the present embodiment, an example is described in which the aperture 16 is configured as an alternative between an open state and a closed state.
The aperture 16 can be configured to adjust the light amount stepwise.

Further, in the present embodiment, an example in which the endoscope apparatus 1 is configured as an electronic endoscope having a solid-state imaging device 27 such as a CCD has been described, but this endoscope apparatus 1 has a fiber bundle or a relay as a transmission optical system. It is also possible to configure as an optical endoscope having a lens system.

5 to 7 relate to a second embodiment of the present invention.
The figure is a sectional view of the tip, FIG. 6 is a side view of the diaphragm, and FIG. 7 is a front view of the diaphragm. The same members as those described in the first embodiment and members having the same functions are denoted by the same reference numerals and description thereof will be omitted.

In this embodiment, the diaphragm 16 provided in the observation through-hole 13 of the distal end main body 11 is configured as a mechanical one operated by an electrostatic motor.

That is, the throttle 16 is composed of a stator 31 and a pair of rotors 32 disposed on the distal end side and the proximal end side of the stator 31.
On the stator 31 side of 32, insulating members 31a, 31a are provided. Electrodes 31b and 32b controlled by the CPU 29 are provided on both surfaces of the stator 31 and on the stator 31 side of the rotor 32. When a voltage is applied to these electrodes 31b and 32b, the pair of rotors 32 are rotated in opposite directions.

Further, the stator 31 has a hole 31c penetrating the central portion thereof, and as shown in FIG. 7, the pair of rotors 32 have holes 32c having a predetermined shape formed symmetrically with each other. The variable window 16a is configured by these holes 32c. When the rotors 32 rotate in opposite directions, the size of the variable window 16a changes, so that the aperture 16 is narrowed or opened.

When the lens 24 is moved toward the optical system 26 as shown by the broken line in FIG. 5 by sliding the rotor 22b of the electrostatic motor 22 via the CPU 29 with this configuration, the CPU 2
The electrodes 31b and 32b of the diaphragm 16 are applied by the
The aperture 32 is rotated in an opposite direction by an angle corresponding to the amount of movement of the rotor 22b, and the area of the variable window 16a is reduced, whereby the aperture 16 is narrowed. Then, the amount of light transmitted through the variable window 16a is reduced, and the optical image has a brightness suitable for observation.

On the other hand, when the lens 24 is moved to the distal end side via the rotor 22b, the area of the variable window 16a is enlarged by rotating the rotor 32 of the diaphragm 16 in the opposite direction via the CPU 29, thereby increasing the amount of transmitted light. Is increased.

8 and 9 relate to a third embodiment of the present invention.
The figure is a schematic configuration diagram of the tip, and FIG. 9 is a cross-sectional view of the tip.

In this embodiment, the holding member 23 of the lens 24 is an electrostatic motor
22 is fixed to the rotor 22b.
6 is provided, while the holding member 23
A contact 37a is provided for sliding contact with the contact. The contact 37a and the base end of the resistor 36 are connected to the resistance value measuring means 3.
8a, a power supply 38b, and the like.

Further, the detecting means 38 is a CP provided at the tip 8.
Connected to U29, this CPU 29 is connected to the application device 20 of the diaphragm 16 and is also connected to the electrostatic motor 22 to turn on or off the switch 20b of the application device 20 according to the resistance value detected by the detection means 38. By turning it off, the aperture 16 is opened or narrowed.

With this configuration, when the rotor 22b and the holding member 23 are moved to the base end side, that is, the short focus side via the CPU 29, the contact 37a
Is slid to the base end side, the resistance value detected by the detection means 38 decreases, and when this reduced resistance value is input to the CPU 29, the CPU 29 switches the switch 20b of the application device 20.
Is turned on, the aperture 16 is stopped down.

When the lens is moved to the long focal length side,
The resistance value detected by 38 increases, and the aperture 16 is opened by the CPU 29 turning off the switch 20b of the application device 20.

10 and 11 relate to a fourth embodiment of the present invention,
The figure is a schematic configuration diagram of the tip, and FIG. 11 is a cross-sectional view of the tip.

In this embodiment, a holding member 23 holding a lens 24 is fixed to a rotor 22b of the electrostatic motor 22, and a driving member 39 having a tip formed in a conical shape is provided on the holding member 23. The stop 16 is constituted by a pair of rotating plates 41a and 41b forming a variable window 16a.

The rotating plates 41a and 41b are S curved in opposite directions.
It is formed in the shape of a letter, and its substantially central portion is crossed and pivotally supported by the holding member 14 by a support pin. Thereby, a drive hole into which the distal end of the drive member 39 whose base end is fixed to the holding member 23 and whose distal end is formed in a cone shape is fitted above the support pin,
The variable windows 16a each having a central portion coinciding with the optical axis are formed below the support pins.
An elastic member (not shown) is stretched at the end of the driving hole side rotating plates 41a and 41b, and the driving hole side ends of the rotating plates 41a and 41b are always close by the elastic member. Biased in the direction.

When the rotor 22b of the electrostatic motor 22 is slid to the base end side by this configuration, the driving member provided on the holding member 23
The variable window 16a of the aperture 16 is moved by moving 39 to the proximal end side.
When the diameter of the aperture 16 is reduced and the aperture 16 is narrowed down, when the rotor 22b is moved toward the distal end, the rotating members 41a and 41b are rotated by the driving member 39, so that the area of the variable window 16a is increased. The aperture 16 is opened.

[Effects of the Invention] As described above, according to the present invention, since the lens is driven by the electrostatic actuator having a simple structure and easy to reduce the thickness, the endoscope is provided with a built-in drive mechanism for focusing. The diameter of the mirror tip can be reduced.

[Brief description of the drawings]

1 to 4 relate to a first embodiment of the present invention, FIG. 1 is a schematic configuration diagram of an endoscope, FIG. 2 is a sectional view of a distal end portion, and FIG.
Fig. 4 is a view taken along the line III-III in Fig. 2, Fig. 4 is an enlarged view of a diaphragm, Figs. 5 to 7 relate to a second embodiment of the present invention, and Fig. 5 is a cross-sectional view of a tip portion. 6, FIG. 6 is a side view of the stop, FIG. 7 is a front view of the stop, FIGS. 8 and 9 relate to a third embodiment of the present invention, FIG. Fig. 10 is a sectional view of the tip, Figs. 10 and 11 relate to a fourth embodiment of the present invention, Fig. 10 is a schematic configuration diagram of the tip, and Fig. 11 is a sectional view of the tip. 8 Tip 16 Aperture 24 Lens

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shoichi Gotanda 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside the Olympus Optical Industrial Co., Ltd. (72) Inventor Takeaki Nakamura 2-43 Hatagaya, Shibuya-ku, Tokyo No. 2 Inside Olympus Optical Co., Ltd. (72) Inventor Masahiro Kawashima 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (72) Toshiyuki Takara 2-43 Hatagaya, Shibuya-ku, Tokyo No. 2 Inside Olympus Optical Co., Ltd. (72) Kenichiro Maki 2-43-2 Hatagaya, Shibuya-ku, Tokyo In-house Olympus Optical Co., Ltd. 2-72 Hatagaya 2-43, Hatagaya, Shibuya-ku, Tokyo No. 2 Olympus Optical Co., Ltd. (56) References JP-A-57-175343 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G02B 23/24 G02B 23/26

Claims (1)

(57) [Claims] 1. An endoscope having an objective optical system at a distal end portion of an endoscope, wherein a focus adjusting lens for adjusting a focus of the objective optical system, a focus adjusting lens, and a plurality of electrodes are provided. A rotor unit having a first electrode group arranged at a predetermined pitch; and a second electrode group having a plurality of electrodes arranged at a different pitch from the first electrode group. A stator means slidably held in the optical axis direction of the optical system; and a voltage applied to a first electrode group of the rotor means and a second electrode group of the stator means, and held by the rotor means. An endoscope comprising: voltage applying means for moving the focus adjusting lens in the optical axis direction.