JPH06254044A - Endoscope - Google Patents

Abstract

PURPOSE:To prevent the generation of moire fringes by inclining one direction among the arranging directions of an optical fiber bundle at a specific angle so as not to overlap on one reference line among the vertical reference lines and horizontal reference lines passing a mark indicating the upward direction of a mask member. CONSTITUTION:The optical fiber bundle 16 provided with an objective lens on the objective side end face of the endoscope is constituted by piling plural pieces of optical fibers 34... on a reference plane, bundling these fibers and converging the fibers to an arranging pattern having directivity in three directions; a reference direction A1 (0 deg.) parallel with the reference plane and a 60 deg. direction A2 and 120 deg. direction A3 with this reference direction A1. The tubular mask 38 formed with a projecting piece 36 indicating the top position of the optical fiber bundle 16 is fixed to the end face of a pipe-shaped mouthpiece converging the optical fiber bundle 16. The optical fiber bundle 16 is so disposed that its reference direction has the angle inclined by 15 deg. to the plus side with the horizontal reference line orthogonal with the vertical reference line B1 passing the projecting piece 36 of the mask 38.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope, and more particularly to an endoscope having an optical fiber bundle as an image guide and a solid-state image pickup device connected to an end surface of an eyepiece portion of the optical fiber bundle.

[0002]

2. Description of the Related Art An endoscope provided with an optical fiber bundle as an image guide has an eyepiece portion formed on a hand-operated portion of the endoscope, and an end surface of the eyepiece portion of the optical fiber bundle is arranged in the eyepiece portion. The image appearing on the end face is observed from the eyepiece portion, or a TV camera having a solid-state image sensor (CCD) is attached to the eyepiece portion to monitor the image on the TV monitor screen.

Further, a mask having a mark indicating the upward direction of the image appearing on the end surface of the eyepiece is disposed on the end surface of the eyepiece of the optical fiber bundle. The TV camera is attached to the eyepiece so that the arrangement direction of CCD pixels is aligned with a vertical reference line passing through the mark indicating the upward direction of the mask member and a horizontal reference line orthogonal to the vertical reference line. To be

[0004]

However, in the conventional endoscope, one of the arranging directions of the optical fibers of the optical fiber bundle is made to coincide with one of the arranging directions of the pixels of the CCD. In addition, since the TV camera is attached to the eyepiece section of the handheld operation section, there is a drawback that moire fringes are likely to occur.

Therefore, in order to eliminate such a problem, an optical low-pass filter is attached between the eyepiece end surface of the optical fiber bundle and the CCD to remove the frequency of the moire fringes. It has the drawbacks that it requires a space for mounting the filter and is expensive. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an endoscope that prevents the occurrence of moire fringes without using an optical low-pass filter.

[0006]

In order to achieve the above-mentioned object, the present invention provides a plurality of optical fibers on a reference plane by stacking them in a bales-like shape and binding them to each other so that the end face of the optical fiber bundle is A reference direction parallel to the reference plane and 60 with respect to the reference direction
An image guide is provided with an optical fiber bundle on which an array pattern having directionality in three directions, ie, the ° direction and the 120 ° direction, is formed, and an image that appears on the end surface of the eyepiece portion is formed on the end surface of the eyepiece portion. In the endoscope in which the mask member having the mark indicating the upward direction is arranged, the optical fiber bundle and the mask member have one of the arrangement directions of the optical fiber bundle,
A vertical reference line that passes through the mark indicating the upward direction of the mask member and one of horizontal reference lines that are orthogonal to the vertical reference line and are inclined relative to each other so as not to overlap. I am trying.

The inclination angle is such that one of the arrangement directions of the optical fiber bundle is relative to one of the vertical reference line and the horizontal reference line of the mask member.
The feature is that the angle is inclined by 15 ° toward the plus side or the minus side.

[0008]

According to the present invention, one of the arrangement directions of the optical fiber bundle does not overlap with one of the vertical reference line and the horizontal reference line passing through the mark indicating the upward direction of the mask member. Since it is relatively inclined as described above, moire fringes do not occur. When connecting the solid-state imaging device to the eyepiece end face side of the optical fiber bundle, one of the arrangement directions of the optical fiber bundle is one of the vertical reference line and the horizontal reference line of the mask member. By setting an angle inclined by 15 ° to the plus side or minus side with respect to the two reference lines,
Since the distance between the pitches at which the end faces of the optical fibers and the pixels of the solid-state image sensor coincide with each other becomes the longest, moire fringes are most unlikely to occur.

[0009]

The preferred embodiments of the endoscope according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a perspective view showing an embodiment of an endoscope 10 according to the present invention. In the figure, the endoscope 10 has a hand operation section 12, and an eyepiece section 14 formed on the hand operation section 12 is provided with an end surface of an eyepiece section of an optical fiber bundle 16 as an image guide. There is.

The optical fiber bundle 16 is provided with the distal end hard portion 2 from the eyepiece portion 14 via the endoscope insertion portion 18 and the bending portion 20.
Up to 2, an objective lens (not shown) is provided on the end face on the objective side. The objective lens can form an image incident from the observation window 24 formed in the distal end hard portion 22 on the end face of the optical fiber bundle 16 on the objective side, and the formed image is an optical fiber. It is transmitted by the bundle 16 to the end surface of the eyepiece portion of the optical fiber bundle 16 and appears as an image on the end surface of the eyepiece portion. The image appearing on the end surface of the eyepiece is the eyepiece 1
An image is formed on the surface of a CCD 28 incorporated in a CCD TV camera 26 that is detachably attached to the camera 4. The image formed on the CCD 28 is photoelectrically converted by the CCD 28, and the photoelectrically converted signal is processed by the processor 30 and displayed on the monitor device 32.

The optical fiber bundle 16 is, as shown in FIG.
A large number of optical fibers 34, 34 ... Are bundled on the reference plane P so as to be stacked in a stack, and the eyepiece end surface thereof has a reference direction A1 (0 °) parallel to the reference plane P and this reference direction. An array pattern having directivity in three directions of 60 ° direction A2 and 120 ° direction A3 with respect to A1 is formed. Further, the optical fiber bundle 16 is converged on a pipe-shaped base (not shown). As shown in FIG. 3, an annular mask 38 having a protrusion 36 indicating the top position of the optical fiber bundle 16 is fixed to the end surface of the base, and the optical fiber bundle 16 has a reference direction A1. , The plus side with respect to one of the vertical reference line B1 passing through the protruding piece 36 of the mask 38 and the horizontal reference line B2 orthogonal to the vertical reference line B1 (in this embodiment, the horizontal reference line B2). It is installed at an angle of 15 °.

On the other hand, the arrangement of the pixels 40 of the CCD 28 is, as shown in FIG. 4, a reference direction C1 parallel to the reference plane P.
(0 °) has directivity in two directions, that is, a direction C2 orthogonal to the reference direction C1. The CCD TV camera 2
6 is an eyepiece portion 14 so that the arrangement directions C1 and C2 of the CCD 28 coincide with the B2 and B1 directions of the mask 38.
Positioned and fixed to.

The positional relationship of the CCD 28 with respect to the eyepiece end surface of the optical fiber bundle 16 will be described below with reference to FIG. As described above, the CCD TV camera 26
Is the B of the mask 38 when the arrangement directions C1 and C2 of the CCD 28 are
Since the optical fibers 34 are fixed to the eyepiece portion 14 so as to coincide with the directions B and B1, the arrangement direction A1 of the optical fibers 34, 34 ...
This means that the CD 28 is inclined 15 ° toward the plus side with respect to the arrangement direction C1.

As a result, the distance between the pitches at which the end faces of the optical fibers 34, 34 ... And the pixels 40, 40. Therefore, generation of moire fringes can be prevented without using an optical low-pass filter. In addition, in the present embodiment, "optical fiber 3
The reference directions A1 of 4, 34 ... Are tilted to the plus side by 15 ° with respect to the horizontal reference direction B2 of the mask 38 '. However, the present invention is not limited to this and may be tilted to the minus side by 15 °.

Further, the arrangement direction A of the optical fibers 34, 34 ...
One of the vertical reference direction B1 of the mask 38 and the horizontal reference direction B2 of the mask 38 may be inclined by 15 ° toward the plus side or by 15 ° toward the minus side. Further, the present invention is not limited to CCDs, and is effective when combined with a device having a grid pattern such as a shadow mask of a TV monitor.

[0016]

As described above, according to the endoscope of the present invention, one of the arrangement directions of the optical fiber bundle is
Prevents moire fringes from occurring without using an optical low-pass filter because it is inclined relative to one of the vertical and horizontal reference lines that pass through the mark indicating the upward direction of the mask member so that they do not overlap. it can.

When the solid-state image pickup device is connected to the end face side of the optical fiber bundle, the one of the arrangement directions of the optical fiber bundle is set to the vertical reference line and the horizontal reference line of the mask member. By tilting 15 ° toward the plus side or the minus side with respect to one of the reference lines, the distance between the pitches at which the end face of the optical fiber and the pixel of the solid-state image sensor match becomes the longest, and the moire fringes are generated most. It's hard to do.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an endoscope according to the present invention.

FIG. 2 is an explanatory diagram showing an arrangement pattern of optical fibers.

FIG. 3 is an explanatory view showing an attachment angle of an optical fiber bundle with respect to a mask.

FIG. 4 is an explanatory view showing an arrangement pattern of CCD pixels.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Endoscope 12 ... Hand operation part 14 ... Eyepiece part 16 ... Optical fiber bundle 26 ... CCDTV camera 28 ... CCD 30 ... Processor 32 ... Monitor device A1, A2, A3 ... Optical fiber arrangement direction C1, C2 ... Pixel Array direction 34 ... Optical fiber 40 ... Pixel

Claims (2)

[Claims] 1. A plurality of optical fibers are stacked and bundled on a reference plane so as to form a stack, so that the end face of the optical fiber bundle has a reference direction parallel to the reference plane and 60 relative to the reference direction.
An image guide is provided with an optical fiber bundle on which an array pattern having directionality in three directions, ie, the ° direction and the 120 ° direction, is formed, and an image that appears on the end surface of the eyepiece portion is formed on the end surface of the eyepiece portion. In the endoscope in which the mask member having the mark indicating the upward direction is arranged, the optical fiber bundle and the mask member are arranged such that one of the arrangement directions of the optical fiber bundle is the upper surface of the mask member. An endoscope characterized in that the vertical reference line passing through the mark indicating the direction and one of the horizontal reference lines orthogonal to the vertical reference line are tilted so as not to overlap with each other. . 2. The inclination angle is such that one of the arrangement directions of the optical fiber bundles is on the plus side with respect to one of the vertical reference line and the horizontal reference line of the mask member, or The endoscope according to claim 1, wherein the angle is 15 ° to the minus side.