JPH10319326A - Focusing mechanism for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize the focusing mechanism of a lens used in an endoscope, etc. SOLUTION: An electromagnetic actuator 60 is constituted of a stator 21 provided on a fixed part and a moving body 31 provided on a moving part. An electromagnetic coil 22 is disposed on the stator 21 along the optical axis of an objective lens at a specified pitch. An electromagnetic coil 32 is disposed on the body 31 along the optical axis of the objective lens at the same pitch as that of the coil 22. The stator 21 and the body 31 are disposed on the leading end part of the endoscope so that the respective coils 22 and 32 face each other. By controlling the direction of a current flowing in the coils 22 and 32, the attracting force and the repulsive force of the polarity of a magnetic field generated on the respective electromagnetic coils drive the body 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focusing mechanism for a lens used in an endoscope or the like.

[0002]

2. Description of the Related Art A conventional endoscope is provided with an insertion portion to be inserted into a body cavity, and an operation portion for operating an objective lens and a treatment member provided at the distal end of the insertion portion. A holding frame for holding the objective lens is provided at the distal end of the insertion section. By operating a wire connected to the holding frame with the operating section, the holding frame is moved along the optical axis of the objective lens, and the focus of the objective lens is adjusted. Adjustments are being made. That is, when an affected part is inspected by inserting an endoscope into the body, the focus is adjusted by moving the objective lens so that the affected part is focused.

[0003]

However, since the wire must be provided at the distal end, there is a problem that the distal end of the insertion portion, which is originally desirably small for the purpose of insertion into a body cavity, becomes large. .

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to reduce the size of a focusing mechanism of a lens used for an endoscope or the like.

[0005]

A focus adjustment mechanism for an endoscope according to the present invention is provided so as to hold a fixed portion and an objective lens and to be movable along the optical axis of the objective lens with respect to the fixed portion. And a moving part is moved by an electromagnetic force generated by an electromagnetic actuator including a stator provided on the fixed part and a moving part provided on the moving part to face the stator. And

Preferably, in the stator, a plurality of magnetic field generating elements are arranged at a predetermined pitch, and in the moving element, the plurality of magnetic field generating elements face the magnetic field generating elements of the stator at the same pitch as the predetermined pitch. It is arranged as follows.

The magnetic field generating elements of the stator and the mover are, for example, electromagnetic coils.

The magnetic field generating element of the stator is, for example, an electromagnetic coil, and the magnetic field generating element of the movable element is a magnet.

The magnetic field generating element of the stator is, for example, a magnet, and the magnetic field generating element of the movable element is an electromagnetic coil.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a distal end portion of the endoscope according to the first embodiment of the present invention. The distal end portion 1 of the endoscope is formed of a flexible cylindrical tube 10 having flexibility.
An observation window 11 made of a transparent member is provided at the tip of the flexible tube 10.
Is provided to prevent foreign matter from entering the inside of the distal end portion 1 of the endoscope. A fixed part 20 is fixed inside the flexible tube 10, and a moving part 30 is provided inside the fixed part 20. The objective lens 40 is supported by the lens support frame 41 in the moving unit 30. A fiber bundle 50 is disposed inside the flexible tube 10 on the opposite side of the observation window 11 with the objective lens 40 interposed therebetween. The fiber bundle 50 has its distal end positioned on the optical axis of the objective lens 40, passes through a communication pipe connecting the distal end portion 1 and a control mechanism (not shown), and forms an object image formed by the objective lens 40. Transmit to control mechanism. In FIG.
A pair of a stator and a movable element, which will be described later, are provided at upper and lower sides of the 0 and the moving unit 30 at positions facing each other, and constitute an electromagnetic actuator 60.

FIG. 2 is an exploded perspective view showing the electromagnetic actuator 60 in an enlarged manner. The electromagnetic actuator 60 includes a stator 21 provided on the fixed part 20 (see FIG. 1) and a movable element 31 provided on the moving part 30 (see FIG. 1). The stator 21 and the moving element 31 are flat plates whose longitudinal directions extend along the optical axis of the objective lens 40 (see FIG. 1).
An electromagnetic coil 22 which is a magnetic field generating element is arranged at a predetermined pitch on the stator 21 along the optical axis of the objective lens 40. Similarly, an electromagnetic coil 32, which is a magnetic field generating element, is arranged on the mover 31 along the optical axis of the objective lens 40 at the same pitch as the electromagnetic coil 22. Electromagnetic coil 22
And the electromagnetic coils 32 face each other.
And the moving element 31 are provided.

The plurality of electromagnetic coils 22 and 32 have a dimension in a direction perpendicular to the plane of the stator 21 and the movable element 31 smaller than a radial dimension in a plane parallel to the plane of the stator 21 and the movable element 31. It is a flat coil, and a magnetic field is generated by passing an electric current. Since an independent power supply is connected to each of the electromagnetic coils 22 and 32,
By controlling the direction of the current, the polarity of the magnetic field of each electromagnetic coil can be controlled independently.

FIGS. 3A to 3C are diagrams showing the polarity patterns of the respective electromagnetic coils 22 and 32 of the electromagnetic actuator 60 shown in FIG. 1. The observation window 11 (see FIG. 1) is provided on the left side. The fiber bundle 50 on the right and left sides (see Fig. 1)
Is the side provided. As described above, the respective electromagnetic coils 22 and 32 are arranged at the same pitch P. The driving control of the objective lens 40 will be described with reference to FIGS. For convenience of explanation, FIG.
In the stator 21 of (c), the third electromagnetic coil from the observation window 11 side is 22a, and the electromagnetic coils arranged continuously to the electromagnetic coil 22a are 22b, 22c, and 22d. Similarly, in the moving element 31, 3
The second electromagnetic coil is defined as 32a, and the electromagnetic coils 32b, 32c, and 32d provided continuously to the electromagnetic coil 32a
And

First, as shown in FIG. 3A, each of the electromagnetic coils 22 has a polarity pattern such that every third coil has the same polarity and every other coil has no polarity. 22 is controlled. In the drawings, a symbol O is given to an electromagnetic coil having no polarity. At the same time, the polarity pattern of the electromagnetic coil 32 is
Are controlled to be opposite in polarity to the above. For example, in FIG. 3A, a current flows so that the electromagnetic coil 22a has the polarity of the N pole and the electromagnetic coil 22c has a polarity of the S pole, and no current flows through the electromagnetic coils 22b and 22d. Further, the electromagnetic coil 3 facing the electromagnetic coil 22a
2a is an S pole, an electromagnetic coil 3 facing the electromagnetic coil 22c.
2c passes an electric current so as to have N-polarity, and does not pass a current to the electromagnetic coils 32b and 32d facing the electromagnetic coils 22b and 22d.

The polarity of the electromagnetic coil 22 is shifted one pitch to the right. That is, the electromagnetic coil 32 having the polarity and the electromagnetic coil 22 on the one-pitch observation window side of the electromagnetic coil 22 opposed thereto have the same polarity, and the electromagnetic coil 32 having the polarity and the one pitch of the electromagnetic coil 22 opposed thereto have the same pitch. The polarity of the electromagnetic coil 22 on the fiber bundle side is reversed. For example, in FIG.
a, 22c to stop the current from flowing through the electromagnetic coil 22b.
, And a current flows so that the electromagnetic coil 22d takes on the polarity of the S pole.

As a result, an attractive force is generated in the electromagnetic coil 32a and the electromagnetic coil 22b, an attractive force is generated in the electromagnetic coil 32c and the electromagnetic coil 22d, and a repulsive force is generated in the electromagnetic coil 32c and the electromagnetic coil 22b. That is, the electromagnetic coil 3 having polarity
2 and the opposing electromagnetic coil 22 on the side of the one-pitch observation window of the electromagnetic coil 22, repulsive force is generated, and the electromagnetic coil 32 having polarity and the opposing electromagnetic coil 22 on the one-pitch fiber bundle side Attracting force is generated between the electromagnetic coil 22 and the electromagnetic coil 22. Therefore, the moving element 31
Is driven one pitch to the fiber bundle side (Fig. 3
(C)).

As described above, the direction and amount of movement of the moving element 31 are controlled by controlling the polarity patterns of the electromagnetic coils 22 and 32. The moving element 31 is a moving unit 30
, The moving unit 30 is driven along the optical axis of the objective lens 40 via the moving element 31, and the focus of the objective lens 40 can be adjusted. Therefore, when the endoscope is inserted into the body to inspect the affected part, each electromagnetic coil 2 is moved to move the objective lens 40 so that the affected part is focused.
Adjust the polarity patterns of 2, 32.

As a second embodiment, in the electromagnetic actuator 60 of the first embodiment, a permanent magnet may be used as a magnetic field generating element instead of the electromagnetic coil 32 of the moving element 31. Further, as a third embodiment, in the electromagnetic actuator 60 of the first embodiment, a permanent magnet may be used as a magnetic field generating element instead of the electromagnetic coil 22 of the stator 21.

As described above, in the first to third embodiments, the objective lens 40 provided at the distal end portion 1 of the endoscope is driven in the optical axis direction by the electromagnetic actuator 60 without using a wire. The endoscope end does not become large.

In the first to third embodiments, the moving element 31 is used.
Is stopped, the magnetic field generating element of the stator 21 and the magnetic field generating element of the movable element 31 are controlled so as to always face each other, so that the amount of movement can be controlled in pitch units of the magnetic field generating element.
Focus adjustment with high accuracy of 0 can be performed.

[0021]

As described above, according to the present invention, the size of the endoscope can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a distal end portion of an endoscope according to the present invention.

FIG. 2 is a perspective view of the electromagnetic actuator of the present invention.

FIG. 3 is a diagram illustrating a polarity pattern of electromagnetic coils of a stator and a moving element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Flexible tube 11 Observation window 20 Fixed part 21 Stator 30 Moving part 31 Movement 22, 32 Electromagnetic coil 50 Fiber bundle 60 Electromagnetic actuator

Claims (5)

[Claims] 1. A fixing unit, comprising: a fixed unit; and a moving unit that holds an objective lens and that is movable with respect to the fixed unit along the optical axis of the objective lens. A focus adjusting mechanism for an endoscope, wherein the moving unit is moved by an electromagnetic force generated by an electromagnetic actuator including a moving unit provided on the moving unit so as to face the child and the stator. 2. A plurality of magnetic field generating elements are arranged at a predetermined pitch in the stator, and a plurality of magnetic field generating elements are arranged at a same pitch as the predetermined pitch in the moving element. The focus adjustment mechanism for an endoscope according to claim 1, wherein the focus adjustment mechanism is disposed so as to face. 3. The focus adjusting mechanism for an endoscope according to claim 2, wherein the magnetic field generating elements of the stator and the mover are electromagnetic coils. 4. The focus adjusting mechanism for an endoscope according to claim 2, wherein the magnetic field generating element of the stator is an electromagnetic coil, and the magnetic field generating element of the movable element is a magnet. 5. The focus adjusting mechanism for an endoscope according to claim 2, wherein the magnetic field generating element of the stator is a magnet, and the magnetic field generating element of the moving element is an electromagnetic coil.