JPH0512686B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an endoscope having an objective optical system unit having a variable magnification or focusing function in its distal end component.

[Conventional technology]

A fixed-focus endoscope has a dust-proof structure for the objective optical system and illumination optical system provided in its distal end component, or has a dust-proof structure for the objective optical system and illumination optical system provided in the distal end component, or has a space inside the optical system that houses the objective optical system and illumination optical system and the inside of the endoscope. A dustproof structure is achieved by providing a dustproof cover etc. between the space and the space. Therefore, the objective optical system and the illumination optical system are dust-proofly isolated not only from the outside but also from the internal space of the endoscope, thereby protecting the optical system from dust.

On the other hand, endoscopes equipped with objective optical systems with variable magnification or focus functions have a structure in which part of the objective lens is moved in the optical axis direction by remote control from the outside, so the internal space of the objective lens is It is extremely difficult to create a dust-proof structure by completely isolating the internal space of the endoscope and the internal space of the endoscope.

In other words, the conventional objective optical system unit of an endoscope with a variable magnification or focus function is composed of a front group lens, a rear group lens, and a variable magnification lens movably disposed between the two in the optical axis direction. There is. This variable power lens is attached to a variable power lens frame having a protrusion on a part of its outer periphery, and is moved in the optical axis direction by pushing and pulling an operating wire connected to the protrusion. . Therefore, the variable power lens is housed inside the rear group lens frame to which the rear group lens is attached, and a protrusion of the variable power lens frame projects outward from the peripheral wall of the rear group lens frame to align the optical axis. A notch is provided to allow movement in the direction. Therefore, the objective lens internal space and the endoscope internal space communicate with each other via the notch.

[Problem that the invention seeks to solve]

As mentioned above, in an endoscope that has an objective optical system with a variable magnification or focus function, the variable magnification lens must be moved in the optical axis direction by remote control from the outside, and the power is transmitted. For this reason, a notch is provided in the lens frame that houses the objective lens.
Therefore, the internal space of the endoscope and the internal space of the objective lens communicate with each other through the notch, and dirt, such as solid lubricant that improves the sliding of built-in objects, flows from the notch into the internal space of the objective lens. There is a risk of metal powder etc. entering. If dust enters the internal space of the objective lens, it is inconvenient that it will be reflected in the image. Therefore, conventionally, filler was injected into the tip component body and the rear group lens frame that constitutes the objective optical system to seal it, but this required injecting the filler into a narrow gap, making it difficult to ensure that the filler was injected into the narrow gap. It is not possible to completely prevent the intrusion of dust.

This invention was made in view of the above-mentioned circumstances, and its purpose is to reliably prevent dust from entering the internal space of the objective lens constituting the objective optical system unit with a simple structure. I can,
An object of the present invention is to provide an endoscope that can always obtain normal endoscopic observation images.

[Means and actions for solving problems]

This invention provides an endoscope equipped with an objective optical system unit having a variable magnification or focusing function in a distal end component, in which the objective optical system unit is arranged between a front group lens frame, a rear group lens frame, and an optical axis between the two frames. Consisting of a movable lens frame that is movable in the direction,
a protrusion provided at both ends of a notch provided in the objective optical system unit; a protrusion of the movable lens frame disposed between the protrusions so as to protrude from the notch; and a blocking member enclosing the notch. This is because the space inside the objective lens and the space inside the endoscope are separated.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows the distal end component of an endoscope equipped with an objective optical system unit having a variable magnification function, and 1 is the main body of the distal end component. This tip structure body 1 is provided with a stepped through hole 4 having a large diameter hole 2 and a small diameter hole 3, and an objective optical system unit 5 having a movable lens, which will be described later, is provided in this through hole 4. There is.

This objective optical system unit 5 will be explained. 6 is a fixed frame, and a cover glass 7 and an infrared cut filter 8 are attached to this fixed frame 6. This infrared cut filter 8 is an infrared absorbing filter made of glass material, and has a coating on its front surface that reflects infrared light. By placing the infrared light cut coating surface on the front side in this manner, the temperature rise of the lens can be reduced. (The total infrared cut rate of this infrared cut filter 8 is 1/10,000.) Furthermore, a front group lens frame 10 is inserted into the rear end of the fixed frame 6 via an insulating tube 9. A front group lens 11 is attached to this front group lens frame 10. The rear end portion of the front group lens 11 projects rearward from the tip component main body 1, and the rear group lens frame 12 is inserted inside this projecting portion. The fixed frame 6, the front group lens frame 10, and the rear group lens frame 12 are provided coaxially, and the rear group lens frame 12 is equipped with a rear group lens 13. Further, a part of the peripheral wall of the rear group lens frame 12 is formed to have a small diameter, and forms a gap 14 between it and the inner peripheral surface of the front group lens frame 10. A notch 15 is provided in a part of the opposing front group lens frame 10 along the optical axis direction. Further, a movable lens frame 16 movable in the optical axis direction is interposed between the front group lens frame 10 and the rear group lens frame 12. A movable lens 17 is attached to the front end of the movable lens frame 16, and the rear end is inserted into the gap 14 between the front group lens frame 10 and the rear group lens frame 12, and is slidable in the front-rear direction. It's starting to move. Further, the fixed frame 6, the movable lens frame 16, and the rear group lens frame 1
A flare diaphragm 18 for preventing flare and ghosting is provided inside the front lens frame 1.
An aperture stop 19 is provided inside the 0.
The flare diaphragm 18 and the aperture diaphragm 19 are formed from a phosphor bronze plate having a thickness of 0.03 mm. The observation depth of the objective optical system unit 5 is 8 to ∞mm on the wide angle (120°) side, and 8 to ∞mm on the narrow angle (60°) side.
With a two-point zoom of 5 to 10 mm on the side, the depth overlap at both positions is 8 to 10 mm. Therefore,
If you approach the subject on the wide-angle side and zoom in when the distance is 8-10mm, you can get a good image even on the narrow-angle side by getting within the depth range. The magnification ratio on the narrow-angle side is 2.3 times that of the wide-angle (screen area ratio).

The front group lens frame 10 and the rear group lens frame 12 configured in this manner are provided with protrusions 20 and 21 facing each other, as shown in FIGS. 2 and 3. Projection portion 20 provided on the front group lens frame 10
is located at the front end of the notch 15 and is housed in the recess 1a provided in the tip component body 1, and the protrusion 21 provided on the rear group lens frame 12 is located at the rear end of the notch 15. positioned. Therefore, protrusions 20 and 21 are provided at the front and rear ends of the notch 15, and a protrusion 22 that projects integrally from the movable lens frame 16 is provided between these. That is, the protrusion 22 is provided on the peripheral wall of the movable lens frame 16, passes through the notch 15, and projects outward from the front group lens frame 10 and the rear group lens frame 12. An operating wire 23 is attached to this protrusion 22.
One end side is connected by a connector 24, and the other end side passes through the protrusion 21 of the rear group lens frame 12 and is connected to an operation knob of a hand operation section (not shown) of the endoscope. . That is, the protrusion 21
A through hole 25 is bored in the through hole 25, and a guide pipe 27 is fixed to this through hole 25 via a fixed pipe 26 which is screwed and fixed. The operation wire 23 is connected to the fixed pipe 26 and the guide pipe 2.
The guide pipe 27 is connected to an insulating tube 28 that covers the operating wire 23 over its entire length.

Further, a dustproof cover 29 as a shielding member is provided between the protrusion 20 of the front group lens frame 10 and the protrusion 21 of the rear group lens frame 12 so as to fit the protrusion 22 together with the notch 15. ing. As shown in FIG. 4, the dustproof cover 29 is made of, for example, a metal plate bent into a U-shape, and is attached to cover the protrusions 20 and 21. Therefore, the objective lens internal space 30 of the objective optical system unit 5 and the endoscope internal space 31 are separated by the pair of protrusions 20 and 21 and the dustproof cover 29. Further, the outer side of this dustproof cover 29 is a front group lens frame 10 and a rear group lens frame 1.
It is covered with an insulating coating 32 which is fitted together with 2.

The objective optical system unit 5 is integrally constructed as described above, and is attached by being inserted into the through hole 4 from the rear of the tip body 1. That is, the fixed frame 6
An annular groove 34 for housing an O-ring 33 is provided on the outer peripheral surface of the
A fixing groove 35 having a V-shaped cross section is provided, and a fixing screw 36 is screwed in the distal end component main body 1 facing the fixing groove 35 in the radial direction. Then, screw in this fixing screw 36 and insert its tip into the fixing groove 36.
By abutting against the tip, the tip component main body 1 and the objective optical system unit 5 are integrally connected. Further, the upward direction of the image is determined by using the protrusions 20 and 2 of the objective optical system unit 5 with respect to the upward direction of the insertion section.
This is done depending on the position of 1. In other words, the protruding portion 20 of the objective optical system unit 5 is arranged so that the position of the recess 1a is estimated with respect to the up position of the tip component main body 1, and the up direction of the solid-state image sensor 37 is projected in advance with respect to the rear group lens frame 12. , 21 into the concave portion 1a of the tip component main body 1, the upward direction of the image can be determined.

In addition, in FIG. 1, 38 is the solid-state image sensor 3.
7, and a solid-state image sensor 37 is attached to the rear group lens frame 12 via an element frame 39.

Figure 5 shows the structure of the water supply pipe provided in the main body 1 of the tip component, and 40 is the first hole drilled from the rear.
41 is the second drill hole drilled from the front.
This is a drill hole. As described above, if the first drill hole 40 and the second drill hole 41 have to be offset from each other due to the layout of the tip component main body 1, a step may be formed in the communication portion 42. Although it causes flow resistance, there is a notch 4 in the pipe wall at the end of the water nozzle pipe 43 inserted into the second drill hole 41.
4, the flow resistance can be reduced.
Note that 45 is a connecting pipe inserted into the first drill hole 40 and connected to the water supply tube 46.

〔Effect of the invention〕

As explained above, according to the present invention, the objective optical system unit is provided with a blocking member to shut off the internal space of the objective lens and the internal space of the endoscope. Since it can be dust-proofed before installation, it is possible to ensure dust-proofing, and the simple structure prevents dust from entering the internal space of the objective lens, making it possible to always obtain normal endoscopic observation images. This effect is achieved.

[Brief explanation of the drawing]

The drawings show one embodiment of the invention.
The figure is a longitudinal side view of the endoscope tip component, FIG. 2 is a sectional view taken along the - line in FIG. 1, FIG. 3 is a sectional view taken along the - line in FIG. The perspective view and FIG. 5 are longitudinal sectional side views showing the structure of the water supply pipe provided in the distal end component. 5... Objective optical system unit, 10... Front group lens frame, 12... Rear group lens frame, 16... Movable lens frame, 29... Dust cover (blocking member), 30...
... Objective lens internal space, 31... Endoscope internal space.

Claims (1)

[Claims] 1. In an endoscope equipped with an objective optical system unit having a variable magnification or focusing function in the distal end component, the objective optical system unit is moved in the optical axis direction between a front group lens frame, a rear group lens frame, and between both frames. a movable lens frame provided in the objective optical system unit, and a protrusion provided at both ends of a notch provided in the objective optical system unit; and a movable lens disposed between the protrusions so as to protrude from the notch. 1. An endoscope, comprising: a protrusion of the frame and a blocking member that covers the notch, thereby blocking an internal space of the objective lens from an internal space of the endoscope.