JPH0938025A - Lens barrel for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a lens barrel from tilting and easily manufacture a means therefor. SOLUTION: A lens barrel 10 is formed in a tubular support 11, holding an observation lens 3 and objective lenses 4, 5, 6. Around the intermediate position of the tubular support 11, a slit 12 is formed and a partition board 14 for positioning an optical member from the slit 12 is set in the support 11. An opening is made on the partition board 14. Since the portioning of the lenses 3-6 is performed by the partition board 14 around the central position of the support 11, tilting of the optical axis of the lenses can be prevented. Since the slit 12 can be formed from the outer periphery of the support 11 and the partition board 14 can be made separately from the support 11, it can be easily made.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel for endoscopes, and more particularly to a structure of a lens barrel which is disposed in a tip portion having a reduced diameter and holds a plurality of lenses and the like.

[0002]

2. Description of the Related Art FIG. 5 shows the structure of a conventional lens barrel arranged at the tip of an endoscope. In the figure, the lens barrel 1
Is an observation window lens 3 in a cylindrical support (lens barrel tube) 2.
Objective lens system lenses 4, 5, and 6 are provided. For example, this objective lens system is put in a cylindrical support 2 in the order of lenses 6, 5, and 4 and finally an observation window lens 3 is attached. In addition to these members, a diaphragm member or the like (optical member) is also arranged.

According to the lens barrel 1 described above, the inside of the object to be observed is captured by the lenses 4, 5 and 6 through the observation window lens 3. For example, in an electronic endoscope, the objective lens system (4, 5,
6) is a CCD (Charge Coupled D) which is a solid-state image sensor.
evice) is optically connected, and the image of the inside of the observed body is captured by the CCD.

[0004]

However, in the above-mentioned lens barrel 1, the diameter of the lens barrel 1 is extremely small because the thin lens barrel 1 is arranged in the endoscope having a diameter of 10 mm or less.
Since the lens barrel 1 has a certain length with respect to this small diameter, there is a problem in that the optical axes of the lenses 3, 4, 5, 6 and the like inside may be inclined and attached. If the optical axes of these lenses 3 to 6 are tilted, it is not possible to obtain good image light inside the object to be observed.

Therefore, in such a case, it is conceivable to form a positioning pad (shelf) as shown in FIG. In the lens barrel 1 of FIG. 6, an annular contact portion 8 is provided on the inner periphery of the support body 7 near a predetermined intermediate position. 3-
By inserting and arranging 6, the inclination of the optical axis of each lens 3 to 6 can be eliminated.

However, in the production of the above-mentioned pad portion 8, the inner diameter of the small-diameter support body 7 is shaved from both ends so that the pad portion 8 is left in the middle portion of the support body 7, and the pad portion 8 is also opened (diaphragm). However, there is a problem that the production becomes complicated because of the provision of.
Further, it is difficult to form the opening and the thickness of the pad portion 8 accurately, and the pad portion 8 itself may be removed after manufacturing.

The present invention has been made in view of the above problems, and an object thereof is to prevent an inclination of a lens and to easily manufacture a means for preventing the inclination. It is to provide a lens barrel.

[0008]

In order to achieve the above object, the present invention provides an endoscope barrel in which an objective lens system optical member is arranged on a cylindrical support, and a slit is formed on the cylindrical support. It is characterized in that a space plate for forming and positioning an optical member disposed inside is provided from the slit into the cylindrical support body.

[0009]

According to the above construction, the spacing plate is arranged inside the cylindrical support through the slit, and the objective lens system member is mounted by using this spacing plate as a positioning member, so that the inclination of the optical axis of the lens is prevented. It In addition, since the spacing plate can be manufactured separately from the support and the slit is formed from the outer periphery of the support, there is an advantage that the manufacturing can be easily performed.

[0010]

1 and 2 show the structure of an endoscope lens barrel according to an embodiment of the present invention, and FIGS.
Shows the configuration of the distal end portion of the side-view endoscope in which the above-mentioned lens barrel is arranged. 1 and 2, the lens barrel 10 has a metal-made cylindrical support (lens barrel tube) 11,
As shown in FIG. 2, the support 11 is provided with slits 12 at vertical positions in the vertical direction. This slit 1
2 is formed by cutting from the outer periphery at a predetermined intermediate position of the support 11.

Further, a metal spacing plate 14 which can be introduced into the inside of the support 11 from the slit 12 is provided. That is, as shown in FIG. 2B, the spacing plate 14 has a width slightly smaller than the circumferential width t of the slit 12, and the spacing plate 14 has an opening 15 used as a diaphragm.
Is formed. Although the slit 12 shown in the drawing has a width larger than the thickness of the spacing plate 14 and has a margin, it can be made substantially the same as the thickness of the spacing plate 14.

In such a lens barrel 10, as shown in FIG. 1, after the spacing plate 14 is arranged in the slit 12 of the support 11, the observation window lens 3 and the lens 4 are first introduced into the support 11. To be done. Then, after positioning the lenses 4 by applying them to the spacing plate 14, the lenses 5 and 6 are introduced into the support body 11, and the lenses 5 and 6 are also positioned, Lens 3
Assembling of ~ 6 is performed. Therefore, these lenses 3 to
Since 6 is positioned near the intermediate position of the support 11,
The optical axis is prevented from being tilted and arranged in the support 11.

In FIGS. 3 and 4, the lens barrel 10 is mounted inside with a set screw 19 or the like in a state where the observation window lens 3 is arranged on the side surface of the tip end portion 18. A CCD 21 is attached to the lens barrel 10 via a prism 20, and an image of the inside of the observed body is picked up by the CCD 21. An irradiation window 22 (FIG. 3) is arranged near the observation window lens 3, and a light guide 23 (FIG. 4) for introducing light is connected to the irradiation window 22. In addition, an upright stand 24 for raising the treatment tool introduced from the treatment tool insertion channel in a predetermined direction is arranged at the distal end portion 18, and the upright stand 24 is driven by a wire 25.

According to the above construction, the spacing plate 14 provided near the intermediate position of the lens barrel 10 or the support 11 allows
Since the lenses 3 to 6 are positioned, the lenses 3 to 6 themselves do not tilt as in the conventional case. Moreover, in manufacturing the lens barrel 10, it is only necessary to form the slit 12 on the support body 11 from the outer side and separately prepare the spacing plate 14 having the opening 15, and as shown in FIG. Compared with a lens barrel having an annular contact portion (8) formed inside (7), the present invention has the advantage of facilitating manufacture, and the contact portion (8) is not removed.

In the above description of the embodiment, only one spacing plate 14 is arranged near the intermediate position of the support body 11. However, a plurality of spacing plates 14 may be arranged according to the length of the lens barrel 10. Good. Further, although the side-viewing type electronic endoscope has been described as an example, the present invention can be applied to a lens barrel used for another endoscope such as a direct-viewing type.

[0016]

As described above, according to the present invention,
Since a slit is formed in the cylindrical support, the spacing plate is arranged from the slit into the support, and the positioning of the optical member arranged inside is performed by the spacing plate,
In addition to being able to prevent the optical axis of the lens from tilting inside the support,
This means for preventing the inclination is advantageous in that it can be easily manufactured and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a configuration of a lens barrel for an endoscope according to an embodiment of the present invention.

2A and 2B show a state in which a spacing plate is removed from the lens barrel of FIG. 1, FIG. 2A is a side sectional view, and FIG. 2B is a sectional view taken along a slit portion.

FIG. 3 is a side view (partial cross section) showing the configuration of the side-view endoscope in the embodiment.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a side sectional view showing a configuration of a conventional endoscope barrel.

FIG. 6 is a side sectional view of a lens barrel when the configuration of FIG. 5 is improved.

[Explanation of symbols]

 1, 10 ... Lens barrel, 2, 11 ... Supporting body, 3 ... Observation window lens, 4, 5, 6 ... Lens, 8 ... Abutting part, 12 ... Slit, 14 ... Interval plate.

Claims (1)

[Claims] 1. In an endoscope barrel in which an objective lens system optical member is arranged on a cylindrical support, a slit is formed in the cylindrical support, and an interval for positioning the optical member arranged inside is formed. A lens barrel for an endoscope, characterized in that a plate is provided from the slit into the tubular support body.