JPH0442816Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endoscope, and more particularly to an endoscope in which a face plate-like image sensor is disposed at its distal end as an imaging element.

In addition to endoscopes that use a so-called optical fiber bundle as an image guide, a TV endoscope has been proposed that uses a face plate-like image sensor that is a matrix arrangement of microphotoreceptors and is combined with a charge transfer device such as a CCD. has been done. This kind of TV endoscope has advantages such as being more durable than conventional endoscopes using image guide fibers, being able to perform various types of processing on electrical signals as video output, and being cost-effective. It is excellent in this respect, and its practical application is being considered.

By the way, the face-plate image sensor used as the tip image sensor of TV endoscopes has recently become considerably smaller due to improvements in manufacturing technology and integration, but it is still not suitable for use in endoscopes. I can't say that. This is because, as is well known, the outer diameter of an endoscope must be small in order to be inserted into a body cavity; for example, for a gastroscope, an outer diameter of about 10 mm or less is desirable. Furthermore, even if the size of the image sensor that is provided has been miniaturized to a satisfactory degree, there is also a demand for improving the resolution, that is, increasing the number of picture elements on the image sensor. works in the direction of increasing.

Against this background, in constructing a so-called TV endoscope, it is important to consider how efficiently the endoscope tip structure, especially the image sensor or the objective optical system for forming an optical image on it, can be constructed in terms of space. An important point is where to place them. Typical tip configurations that have been proposed so far include, in direct-viewing endoscopes, a face plate-like image sensor is placed along a plane perpendicular to the longitudinal direction (insertion direction) of the endoscope. However, in the case of a side-viewing endoscope, the optical image from the direct-viewing objective optical system is directly formed, or the image sensor is placed along the longitudinal direction of the endoscope and close to one side wall of the endoscope. , one in which an optical image from a side-viewing objective optical system is formed is known. However, the conventional type tip structure described above,
When trying to incorporate a realistic image sensor,
It's extremely unreasonable. This is because in the former case, when considering the cross section of the distal end, the image sensor face plate occupies most of the area within that plane, and other members required for the endoscope, such as the light guide channel, forceps channel, etc. It becomes very difficult to provide air and water channels. On the other hand, in the latter case, the image sensor face plate is placed on one side of the endoscope, and the optical image from the side-viewing objective optical system provided on the other side is focused on this, so the cross section of the tip is also considered. The side-view objective optical system occupies most of the area, and since the image sensor face plate is placed close to one side wall of the endoscope, which is said to preferably have a shape close to circular in cross-section, its cross-sectional shape is also difficult. Considerable changes are expected.

In addition, compared to conventional endoscopes that use optical fiber bundles as image guides, TV endoscopes have a more complex imaging system structure due to the arrangement of the image sensor. The problem is coordination.

[Purpose of invention]

The present invention was developed in view of the above circumstances, and allows a face plate-shaped image sensor to be placed without making the tip of the insertion section of the endoscope thicker. The purpose is to propose an endoscope that can be easily adjusted.

[Summary of the idea]

The imaging system of the present invention includes an objective optical system, an optical path converting prism, and a plate-shaped image sensor as one unit. That is, the face plate-like image sensor is arranged on a plane that includes the central axis in the longitudinal direction of the endoscope. The prism is fixed to the plate-shaped image sensor, and the objective optical system is attached to the prism to which the plate-shaped image sensor is fixed for optical adjustment such as focus adjustment and optical axis alignment. It is movable relative to the prism and is fixed to the prism after the optical adjustment, and the objective optical system, prism, and face plate-like image sensor are configured as a unit.

〔Example〕

Hereinafter, preferred embodiments of the endoscope according to the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show an example in which the present invention is applied to a direct-viewing endoscope, as a side sectional view of the distal end and a schematic front view, respectively. As shown in FIG.
and a flexible portion 14. Hard tip part 1
2 is made up of a metal tip 16 and cannot be bent, but the flexible part 14 is formed of a plurality of connected joint rings 18, and can be bent vertically and horizontally using a known operation wire (not shown). As shown in FIG. 2, in addition to the objective optical system 20, the endoscope tip 10 has light guide channels 22, 24, a forceps channel 26, and an air/water supply channel 28 in the longitudinal direction of the endoscope (see FIG. 1). It is inserted in the left and right direction at the top. As is clear from FIG. 1, the objective optical system 20 generally has a plurality of lens configurations, but in the present invention, a right angle prism 30 is provided behind it to convert the optical path of the objective optical system 20 by 90 degrees. A rectangular face plate-like image sensor 32 is bonded to the light exit surface.

The objective optical system 20 is connected to the endoscope tip 10 in the following order.
installed within. First, when displaying on a monitor TV, etc., use the image sensor 3 to prevent the image from falling over.
The arrangement direction of the picture elements No. 2 and the direction of the prism 30 are aligned using a jig or the like, and the prism 30 is fixed onto the image sensor 32 with an adhesive. Next, focus adjustment and optical axis alignment of the objective optical system 20 are performed using a jig or the like with respect to the bonded block of the image sensor 32 and prism 30. That is, the lens barrel 20A of the objective optical system 20 is slid within the lens barrel 30A on the prism 30 side, and the optical image is transmitted to the image sensor 3.
At the same time, the optical axis of the objective optical system 20 and the optical axis of the prism 30 are aligned. After completing this adjustment, the objective optical system 20 is fixed onto the prism 30 with adhesive. As a result, the image sensor 32 and the objective optical system 20 are configured as one unit, and there is no misalignment of their optical axes. Objective optical system 20 configured as follows,
A unit consisting of a prism 30 and an image sensor 32 is inserted into the tip fitting 16. Next, while watching the monitor TV, slide the unit within the bracket 16 so that the object at a predetermined distance from the tip of the tip bracket 16 becomes a predetermined size on the monitor TV, position it, and move the optical axis of the unit to the tip. Adjustment is made so that it is parallel to the central axis XX of the section 10.
After this adjustment, the unit is fixed to the tip fitting 16 with adhesive or the like.

The image sensor 32 is connected to the central axis in the longitudinal direction of the endoscope (X-X line in FIG. 1 and X1-X1 line in FIG. 2).
The outer diameter of the endoscope can be used effectively. Openings are formed in the tip metal fitting 16 in accordance with other various channels. For example, a forceps tube 36 is connected to the forceps channel 26 as shown in FIG. 1, and the forceps are inserted therein. As is clear from FIGS. 1 and 2, the substrate 38 of the image sensor 32 is formed to be slightly longer than the image sensor 32 in the width direction (the diameter direction of the endoscope insertion part), and The insertion portions are formed to have substantially the same length (longitudinal direction). Lead wires 40 of image sensor 32 are connected to substrate 38 and to individual microphotoreceptors of image sensor 32 . The lead wire 40 sends a drive signal from a drive circuit of a control unit (not shown) to the image sensor 32, and also sends a video signal from the image sensor 32 to the control unit.

The distal end portion 10 of the endoscope insertion section is divided into an upper side and a lower side with the image sensor 32 as a boundary in FIG. The lead wire 40 is located behind this objective optical system 20. That is,
The image sensor 32 is aligned with the central axis X in the longitudinal direction of the endoscope.
- When placed on a surface containing X-rays, the image sensor 32 can be highly integrated without making the tip of the endoscope thicker.
Furthermore, the relatively space-consuming forceps channel 26 and the objective optical system 20 can be arranged above and below it. Further, the lead wire 40 can be placed in a space below the image sensor 32 and behind the objective optical system 20 without interfering with other members.

According to the embodiment of the endoscope according to the present invention configured as described above, it is possible to sufficiently accommodate the size of the image sensor 32 whose one side is about the outer diameter of the tip of the endoscope.
The side on which the objective optical system 20 is not provided can be used as a space unrelated to the imaging body, and therefore, the forceps channel 26, air/water supply channel 28, etc. can be freely installed in that space in the form described above. It will be possible to place it.

Further, according to the embodiment, the forceps channel 26 is disposed on the upper side divided by the image sensor 32 in FIG. 1, and the objective optical system 20 is disposed on the lower side. can be used, and the lead wire 40 can be freely arranged in this space.

In the first and second embodiments, a direct-viewing endoscope has been described, but the present invention can also be applied to a side-viewing endoscope. For side-viewing endoscopes, Figure 1
In addition to the prism 30 of the direct-viewing endoscope shown in FIG. 2, a side-viewing prism is arranged at the front of the objective optical system 20.

[Effect of idea]

As explained above, according to the endoscope according to the present invention, the lens barrel on the prism side and the lens barrel of the objective optical system are slidably fitted between the prism and the objective optical system, and are moved relative to each other. Since we have provided an adjustment mechanism that can be adjusted,
After optical adjustment, the imaging unit can be fixed to the distal end of the endoscope, and the optical adjustment can be easily performed.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing a case where an embodiment of the endoscope according to the present invention is applied to a direct-viewing endoscope, and FIG. 2 is a schematic front view thereof. 10... endoscope tip, 16... tip metal fitting, 2
0... Objective optical system, 30... Prism, 32...
Image sensor, 40...Lead wire.

Claims (1)

[Scope of utility model registration request] It includes an objective optical system disposed along the longitudinal direction of the endoscope, a prism that polarizes the optical path from the objective optical system, and an axis fixed to the light exit surface side of the prism and extending along the longitudinal direction of the endoscope. In an endoscope including a face plate-like image sensor arranged on a surface, a lens barrel on the prism side and a lens barrel of the objective optical system are slidably fitted between the prism and the objective optical system. An endoscope characterized by being provided with an adjustment mechanism that can adjust relative movement.