JP3209070U - Endoscope - Google Patents

Abstract

An endoscope capable of accurately controlling the rotation of an observation image with a simple and space-saving structure. An endoscope according to the present invention includes an insertion portion having an objective lens at a distal end and a cylindrical proximal end portion having an eyepiece, and the proximal end portion 10 is located behind the endoscope body of the eyepiece. It is characterized by having two dove prisms 11 arranged in series along the optical axis X and a rotating means 12 for rotating one of the two dove prisms 11b on the end side. [Selection] Figure 2

Description

  The present invention relates to an endoscope, and more particularly to an endoscope that can accurately control the rotation of an observation image with a simple and space-saving structure.

  2. Description of the Related Art In recent years, an image observed by an endoscope is mainly observed on an image display means such as a monitor from an insertion unit having an objective lens at a distal end through an image transmission medium such as an image fiber. It is. Further, in some fields, the observation may be made visually because it can be observed with a simple configuration as compared with the case of observing with the above-described image display means.

  However, when observing with these endoscopes, there is a problem that the vertical direction of the observed image is shifted in the rotation direction and may not be displayed correctly. Since the vertical direction of the observed image (hereinafter referred to as “observation image”) is determined by the rotational direction of the distal end of the insertion portion, when the insertion portion is inserted into the body, the entire insertion portion is twisted. Will cause the top and bottom of the observation image to shift in the rotational direction.

In order to eliminate the vertical displacement of the observation image, there is a method in which the endoscope itself is rotated and adjusted so that the vertical relationship of the observation image is correct. However, it is very difficult to rotate the endoscope itself inserted in the body with the insertion portion bent, and it is difficult to control the rotation angle, and the vertical direction of the observation image is accurately adjusted. I couldn't.
Further, there is a technique in which the observation image displayed on a monitor or the like is digitally edited to rotate the observation image and adjust the vertical direction correctly. In this case, although the vertical direction of the observation image can be adjusted, a separate device for editing the image is required. Therefore, the rotation angle of the observation image is controlled and the vertical direction is adjusted with a simpler configuration. A technology that could be used was also desired.

  In view of the above problems, an object of the present invention is to provide an endoscope capable of accurately controlling the rotation of an observation image with a simple and space-saving structure.

  As a result of earnest research to solve the above problems, the inventors of the present invention have found that an endoscope having an insertion portion having an objective lens at a distal end and a cylindrical proximal end portion having an eyepiece lens. Two dove prisms are provided on the rear end side of the endoscope body (opposite to the observation object), and one of them is rotated around the optical axis. Thus, it was found that the rotation of the observation image can be accurately controlled.

The present invention has been made based on such knowledge, and the summary thereof is as follows.
An endoscope according to the present invention includes an insertion portion having an objective lens at a distal end and a cylindrical proximal end portion having an eyepiece, and the proximal end portion is located on the rear end side of the endoscope main body of the eyepiece. It has two dove prisms arranged along the optical axis, and rotating means for rotating one of the two dove prisms around the optical axis.
By providing the above configuration, the rotation of the observation image can be accurately controlled with a simple and space-saving structure.

  In the endoscope according to the present invention, it is preferable that both of the two dove prisms have a refractive index (nd) of 1.510 or more and an Abbe number (νd) of 63 or more. This is because it can contribute to better space saving.

  Furthermore, in the endoscope according to the present invention, it is preferable that each of the two dove prisms has a height of 3 to 5 mm and a length of 8.5 to 16 mm. This is because it can contribute to better space saving.

  Furthermore, in the endoscope according to the present invention, it is preferable that the main body outer shape of the base end portion is 15 mm or less. This is because it can contribute to better space saving.

  According to the present invention, it is possible to provide an endoscope that can accurately control the rotation of an observation image with a simple and space-saving structure.

It is the perspective view which showed typically one Embodiment of the endoscope of this invention. FIGS. 2A and 2B are cross-sectional views schematically showing a cross section in the A direction with respect to the proximal end portion of the endoscope shown in FIG. 1, in which FIG. The rotated state is shown. (A) shows an image state when an image is observed through one dove prism, and (b) shows an image state when the image is observed through two dove prisms.

The endoscope of the present invention will be described with reference to the drawings.
FIG. 1 schematically shows an example of an endoscope of the present invention. FIGS. 2A and 2B are views in the direction A of the proximal end portion of the endoscope shown in FIG. The cross section is schematically shown.
In addition, “the distal end side of the endoscope body (hereinafter sometimes referred to as“ the distal end side ”)”, which will be described later, refers to the distal end side (observation object side) of the insertion portion of the endoscope body. The rear end side of the endoscope main body (hereinafter sometimes referred to as “front end side”) indicates the rear end side (observer side) of the proximal end portion of the endoscope main body.
Further, the “optical axis X” described later is not an optical axis after being refracted in the Dove prism, but an optical axis until it enters the Dove prism and is emitted from the Dove prism.

As shown in FIG. 1, an endoscope 1 according to the present invention includes an insertion portion 20 having an objective lens at a distal end 20a and a cylindrical proximal end portion 10 having an eyepiece.
And, as shown in FIGS. 2A and 2B, the endoscope 1 according to the present invention has the proximal end portion 10 on the optical axis X on the rear end side of the endoscope body of the eyepiece 13. Two dove prisms 11 arranged in series along the axis, and rotating means 12 for rotating one of the two dove prisms 11 (in FIG. 2, the dove prism 11b located on the rear end side of the endoscope main body). It is characterized by that.

Here, the Dove prism is an optical element processed into a trapezoidal shape as shown in FIG. 2A, and the image is inverted when the image is observed through the Dove prism, and the longitudinal direction of the Dove prism is used as an axis. When rotated, the image appears to rotate with twice the amount of rotation.
Therefore, when an observation object is observed with the endoscope of the present invention, the observation image formed by the objective lens or the eyepiece lens 13 passes through the dove prism 11a located on the distal end side, so that the image is inverted. Thereafter, the inverted observation image passes through the dove prism 11b on the rear end side, so that the inverted observation image is inverted again to form a normal observation image, and the dove prism 11b is adjusted around the optical axis X. By rotating while rotating (FIG. 2B), it is possible to accurately control the rotation (vertical direction) of the observation image.

FIG. 3 shows a case where an image is observed through one dove prism (FIG. 3A) and an image is observed through two dove prisms arranged in series along the optical axis X (FIG. 3B). Is a comparison. Note that an image composed of large and small squares is observed so that the inversion of the image at the time of each observation can be seen.
As can be seen from FIG. 3, when the image is observed through one Dove prism rotated about 15 degrees around the optical axis X (FIG. 3A), the image appears to be rotated and inverted by 30 degrees. However, when the image is observed through the two dove prisms, it can be seen that the image is rotated by 30 ° in a state where the image is not reversed (FIG. 3B). By using this function and adjusting the rotation angle of one of the dove prisms, the rotation angle of the observed image can be adjusted.

The dove prism is not particularly limited as long as the above-described operation can be realized, and a commercially available dove prism can also be used.
However, the refractive index (nd) of the two dove prisms 11a and 11b is preferably 1.510 or more and 1.550 or more from the viewpoint that the dove prism can be miniaturized and space can be saved. It is more preferable that it is 1.565 or more. Further, from the viewpoint of suppressing the color blur of the observation image that has passed through the Dove prism, it is preferable that the Abbe numbers (νd) of the two Dove prisms 11a and 11b are both 63 or more. More preferably, it is more preferably 65 or more. The upper limit of these parameters is not particularly limited, but from the viewpoint of operability and suppression of color blur of the observed image, the refractive index (nd) is 1.599 and the Abbe number (νd) is about 65.6. Preferably there is.

The dove prism 11 is preferably downsized from the viewpoint of space saving as described above. For example, the length L of the dove prism 11 (the size of the portion having the largest value in the longitudinal direction of the tab prism) is preferably 8.7 mm. The height H of the dove prism 11 (the size in the direction perpendicular to the longitudinal direction of the tab prism) is preferably 3 mm. Note that the length L of the Dove prism depends on the height H. The smaller the height H, the shorter the length L, but it is limited by the size of the image. If the height H is too small, the periphery of the image may be vignetted (part of the periphery of the image is missing). For this reason, the height H of the Dove prism is 3 to 5 mm and the length L is 8.5 to 16 mm, which is a suitable size.
Further, as shown in FIG. 1 (a), the distance from the Dove prism 11a located on the distal end side to the eyepiece lens 13 (distance M where the Dove prism 11a and the eyepiece lens 13 are closest to each other) is omitted. From the standpoint of space, the closer it is, the more preferable, specifically 1 mm or less.
Furthermore, an arrangement interval between the Dove prism 11a located on the front end side and the Dove prism 11b located on the rear end side (the Dove prism 11a located on the front end side and the Dove prism 11b located on the rear end side are closest to each other). It is preferable that the interval P) is as small as possible from the viewpoint of space saving.

  The optical constants and dimensions of the two dove prisms 11 are preferably the same from the viewpoint of easy accurate rotation control of the observation image. However, if accurate rotation control of the observed image can be performed, it is also possible to use Dove prisms having different dimensions and optical constants.

Here, as shown in FIG. 2A, the base end portion 10 is composed of main bodies 10 a and 10 b of the base end portion 10 and a cover portion 16. In the present invention, the base end body may be referred to as a base end portion.
The method for fixing the Dove prism 11 at the base end portion 10 is not particularly limited as long as it does not interfere with the reflection of the lower bottom portion of the Dove prism, and the method is not particularly limited. For example, as shown in FIG. 2, the main bodies 10 a and 10 b of the base end portion 10 and the dove prisms 11 a and 11 b can be connected via a predetermined connecting member 15. Since the base end main bodies 10a and 10b are cylindrical, by connecting the dove prism 11 via the connecting member 15, the arrangement position of the dove prism can be accurately controlled. The connecting member 15 may be replaced with an adhesive or the like as long as the position of the dove prism can be accurately controlled.

The size of the base end portion 10 is preferably as small as possible from the viewpoint of space saving. The Dove prism 11 and, depending on the size of the eyepiece 13, specifically, the outer diameter R ₁ of the part of the body 10a, 10b of the proximal portion 10 is preferably 15mm or less, 10 mm The following is more preferable. The inner diameter R ₂ of the proximal portion 10 is preferably 6mm or less, more preferably 5mm or less.

  As shown in FIG. 2B, the rotating means 12 has one of the dove prisms 11 (in FIG. 2, the dove prism 11b located on the rear end side of the endoscope body) as an axis of rotation. Rotate. Thus, it is possible to accurately control the rotation (vertical direction) of the observation image while inverting the inverted observation image after passing through the dove prism 11a located on the tip side to form a normal observation image again. It becomes possible.

Here, the mechanism of the rotating means 12 is not particularly limited as long as one of the Dove prisms can be rotated around the optical axis X.
For example, the rotating means 12 can be rotated manually so as to be rotatable. Moreover, it is also possible to rotate it electrically by attaching a motor or a gear. However, it is preferable to rotate manually from the viewpoint of a simple and space-saving structure.
Further, when one of the dove prisms is rotated around the optical axis X by the rotating means 12, a part 10b of the main body of the base end 10 and the rear end side can be rotated. The dove prism 11b can be rotated, and the main body of the base end portion 10 is fixed, and by rotating a part of the connecting portion 15, the dove prism 11b on the rear end side is rotated. You can also.

  In FIG. 2B, of the two dove prisms 11, the dove prism 11b located on the rear end side of the endoscope body is rotating. However, the dove prism 11a on the front end side is rotated. You can also. However, from the viewpoint of ease of control of the rotation angle, it is preferable that the rear end side dove prism 11b be rotated.

In addition to the eyepiece lens 13, the dove prism 11, and the rotating means 12 described above, the base end portion 10 can also include members such as an image sensor (not shown) and a relay lens 14 as necessary. .
The imaging element is provided on the further rear end side of the dove prism 11b located on the rear end side of the endoscope body, and the relay lens 14 is provided on the further front end side of the eyepiece lens 13.

As shown in FIG. 1, the endoscope of the present invention has an operation unit 30 and an insertion unit 20 on the distal end side of the endoscope main body at the distal end side of the proximal end portion and an endoscope body rear end side of the proximal end portion. The mount part 40 can further be provided.
Here, the configuration of the operation unit 30, the insertion unit 20, and the mount unit 40 is not particularly limited, and an operation unit and an insertion unit used in a conventional endoscope can be appropriately used.

  Further, the insertion portion 20 may be manufactured using either a hard material or a flexible material. That is, the endoscope of the present invention may be a so-called hard mirror or soft mirror.

DESCRIPTION OF SYMBOLS 1 Endoscope 10 Base end part 11 Two dove prisms 11a Dove prism 11b of the endoscope main body front end side Dove prism 12 of the endoscope main body rear end side Rotating means 13 Eyepiece 14 Relay lens 15 Connection part 16 Cover part 20 Insert portion 20a Insert portion distal end 30 Operation portion 40 Mount portion

Claims (4)

An insertion portion having an objective lens at the distal end and a cylindrical proximal end portion having an eyepiece;
The base end portion rotates two dove prisms arranged in series along the optical axis on the rear end side of the endoscope body of the eyepiece and one of the two dove prisms around the optical axis. An endoscope having a rotating means.   2. The endoscope according to claim 1, wherein each of the two dove prisms has a refractive index (nd) of 1.510 or more and an Abbe number (νd) of 63 or more.   The endoscope according to claim 1 or 2, wherein each of the two dove prisms has a height of 3 to 5 mm and a length of 8.5 to 16 mm. The endoscope according to claim 3, wherein an outer diameter of the main body of the base end portion is 15 mm or less.

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