JP4317285B2 - Endoscopic imaging device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus for an endoscope, and more particularly to a structure of an imaging apparatus that holds a lens barrel movably in an optical axis direction by a lens barrel holding member during assembly.
[0002]
[Prior art]
FIG. 4 shows a configuration of an imaging apparatus used in a conventional electronic endoscope or the like. This imaging device is arranged in the distal end portion of the endoscope. As shown in FIG. 4A, the lens barrel 3 holding the objective optical system (lens group) 1 in the lens frame 2 and the lens barrel 3 are arranged. A lens barrel holding member 4 that holds the lens 100 so as to be movable in the optical axis direction 100 is provided, and the first lens 1A of the objective optical system 1 is disposed on the distal end surface.
[0003]
A prism 5 is attached to the rear of the lens barrel holding member 4, and a CCD (Charge Coupled Device) 7 that is a solid-state imaging device is optically connected to the prism 5 through a cover glass 6. The CCD 7 is housed in a package 8 that functions as a circuit board, and the upper side thereof is closed by the cover glass 6, and a signal line for transmitting a video signal is connected to the package 8.
[0004]
According to such an imaging apparatus, the image light captured by the objective optical system 1 is reflected by the prism 5 and reaches the imaging surface (upper surface) of the CCD 7, and the CCD 7 corresponds to incident light. The charge amount is output as a video signal, and the video signal is processed to form an image in the observed body.
[0005]
[Problems to be solved by the invention]
However, in this type of endoscope imaging device, the length L1 of the optical path space of the lens barrel holding member 4 may be longer than the length L2 of the lens barrel 3, as shown in FIG. In this case, there is a problem that the lens barrel 3 enters the lens barrel holding member 4 as shown in FIG.
[0006]
That is, the lens barrel holding member 4 serves to set the focusing and imaging size of the imaging system to a predetermined size at the time of assembly by enabling the lens barrel 3 to move back and forth in the optical axis direction 100. . In the endoscope, the size of image display on the monitor is set to various sizes by adjusting the image formation size on the imaging surface of the CCD 7, and for example, the entire area of the image obtained by the objective optical system ( It is adapted to a type that displays a circular region), a type that displays a region where the top and bottom, left and right are missing (this lacking ratio has various sizes), and the like.
[0007]
In general, the length L1 of the lens barrel holding member 4 is set from the beginning in accordance with a predetermined imaging size of the production model. Conversely, the lens barrel is adjusted so as to be adjusted to various imaging sizes. It is also possible to increase the length L1 of the holding member 4. However, in this case, as shown in FIG. 4 (B), the lens barrel 3 enters the lens barrel holding member 4 and cannot come out to the front side.
[0008]
On the other hand, even if the length L1 of the lens barrel holding member 4 is considered in terms of the holding function, if the fitting length is short, the lens barrel 3 cannot be held with sufficient strength, and shaft runout or the like may occur. Therefore, a longer length L1 is better.
[0009]
Therefore, it is also possible to employ the cutting structure shown in FIG. 5 as a solution when the lens barrel 3 is immersed. That is, as shown in the drawing, a groove-like cut 10 having an open end on the front side is provided in the horizontal direction on, for example, the left and right side surfaces of the barrel holding member 4. According to this, when the lens barrel 3 enters the holding member 4, the lens barrel 3 can be grasped by the tweezers-like jig through the above-described notch 10 and pulled out. However, since the diameters of the lens barrel 3 and the lens barrel holding member 4 are as small as millimeters, the drawing operation with a jig becomes complicated.
[0010]
The present invention has been made in view of the above problems, and an object of the present invention is to provide an imaging apparatus for an endoscope in which the lens barrel does not enter the lens barrel holding member and the drawing work with a jig or the like is not required. It is to provide.
[0011]
[Means for Solving the Problems]
To achieve the above object, according to the present invention, a lens barrel having a length L2 for attaching an objective optical system lens to a lens frame member, and holding the lens barrel movably in the optical axis direction, the lens barrel length L2 is provided. In an endoscope imaging apparatus comprising: a lens barrel holding member having a longer optical path space of L1; and an extension portion in which the lens frame member protrudes in the optical axis direction at the rear end portion of the lens barrel (immersive preventing means) is provided, the length L3 of the extending portion, L3> by setting L1 -L2, the barrel is prevented from immersion to the optical path space within the barrel holding member It is characterized by that.
[0012]
According to the above configuration, as immersive prevention means extending portion all or part of the rear end portion was extended only in the optical axis direction by a predetermined length of the lenses frame member (holding member) is provided, mirror Even when this extension part hits the rear end surface of the lens barrel holding member due to the movement toward the rear side of the lens barrel, the front side of the lens barrel protrudes from the lens barrel holding member, and the mirror is held in the lens barrel holding member. The torso never gets in.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
1, the structure of the endoscopic imaging apparatus according to an exemplary form Tairei (solid-state imaging device assembled body) is shown. As shown in the figure, this imaging apparatus is basically the same as the conventional one, and the lens barrel 12 includes an objective optical system (lens group) 1 including a first lens 1A arranged on the distal end surface of the endoscope as a lens frame. 13 to hold. The lens barrel 12 is held in the lens barrel holding member 4 so as to be movable in the optical axis direction 100.
[0014]
A prism 5 is attached behind the lens barrel holding member 4, and a CCD 7, which is a solid-state image sensor, is optically connected to the prism 5 through a cover glass 6. That is, the CCD 7 is housed in a package 8 that functions as a circuit board, and the upper surface of the package 8 is covered with the cover glass 6. Although not shown, a video signal is transmitted to the package 8. Signal lines are connected.
[0015]
As shown in FIGS. 1B and 2, the lens frame 13 of the lens barrel 12 has an extended portion in which the frame member protrudes in the optical axis direction by a length L3 at the rear end. 13A is provided. That is, the portion of the lens barrel 12 where the objective optical system 1 is disposed has a length L2 as in the prior art, and a cylindrical extending portion 13A having no contents is provided behind the lens barrel 12 having the length L2. Form. The length L3 of the extending portion 13A is set so that the value added to the length L2 of the main body portion is longer than the length L1 of the lens barrel holding member 4 (L2 + L3> L1), that is, L3> L1. Set to -L2. Instead of the extending portion 13A, an extending portion 13B in which a part of the cylindrical lens frame 13 is extended can be provided as shown in FIG.
[0016]
Exemplary form Tairei has the above configuration, the imaging apparatus of Figure 1, by moving the barrel 12 at barrel holding member within 4 along the optical axis 100, and adjustment of the image size at the imaging surface of CCD7 Focusing will be performed. As described above, some endoscopes have different types of image frames (circle regions) displayed on the monitor screen, and the optical axis direction of the lens barrel 12 is set so as to have an image formation size that matches the size. Adjust the position of 100.
[0017]
When the optical adjustment of the lens barrel 12 is performed, even if the lens barrel 12 is moved to the rear end portion, the extension portion 13A (or 13B) abuts against the inner rear end surface of the lens barrel holding member 4. The lens barrel 12 itself does not enter the lens barrel holding member 4 as in the prior art, and the image formation size adjustment and focusing can be performed smoothly.
[0020]
【The invention's effect】
As described above, according to the present invention, in the imaging apparatus including the lens barrel holding member having the optical path space of L1 longer than the lens barrel length L2 , the lens frame member is optically connected to the rear end portion of the lens barrel. By providing an extending portion protruding in the axial direction and setting the length L3 of the extending portion to L3> L1−L2, the lens barrel can be immersed in the optical path space in the lens barrel holding member. Having prevented, without entering the lens barrel into the barrel holding member during assembly, the lead working becomes unnecessary due to the jig or the like, can be adjusted and focusing the image formation size satisfactorily.
[Brief description of the drawings]
[1] a side sectional view showing the configuration of the endoscope imaging apparatus according to an exemplary form Tairei of the present invention, FIG. (B) are views of a state in which moving the barrel to the rear end.
FIG. 2 is an external perspective view showing a lens barrel of the embodiment.
FIG. 3 is a side cross-sectional view showing a configuration of a conventional endoscope imaging device, and FIG. 3B is a diagram showing a state in which a lens barrel is moved to a rear end portion.
FIG. 4 is a side view of an imaging apparatus showing an example for solving a conventional problem.

Claims (1)

A lens barrel of length L2 for attaching the objective optical system lens to the lens frame member;
An endoscope imaging apparatus comprising: a lens barrel holding member that holds the lens barrel movably in the optical axis direction and has an optical path space of L1 longer than the lens barrel length L2 .
Provided at the rear end of the lens barrel is an extension that projects the lens frame member in the optical axis direction,
The length L3 of the extending portion, by setting the L3> L1 -L2, among which the barrel is characterized by being prevented from immersion to the optical path space within the barrel holding member endoscope Imaging device.

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