JP2000304992A - Stop device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a small-sized stop device which prevents an adhesive stuck part, an adhesive enclosed part, etc., which cause a flange generation, from being formed when an adhesive with superior fluidity is poured into the gap between an optical lens and a lens frame to reach a stop opening. SOLUTION: On a 1st lens frame constituting the stop device, a 1st objective 11, a flow stop member 14, a luminance stop 13, and a 2nd objective 12 are arranged. An opening 13a of a specific diameter size is formed at the center part of the luminance stop 13. The flow stop member 14 has a through hole 14a having a larger diameter than the aperture 13a of the luminance stop 13. The adhesive 16 flowing in the gap between the 1st objective and flow stop member 14 reaches the edge of the through hole 14a of the flow stop member 14 to flow along the peripheral surface of the through hole 14a and then flows in the gap between the flow stop member 14 and luminance stop 13, so that it is solidified. Consequently, the adhesive 16 never reaches the opening 13a of the luminance stop 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm device formed by fixing a plurality of optical systems to a lens frame with an adhesive.

[0002]

2. Description of the Related Art In recent years, observations have been made by inserting an elongated insertion portion into a body cavity and inserting it into a medical endoscope for observing the body cavity, a pipe of a chemical plant or a jet engine, or a machine. In addition, industrial endoscopes used for inspection and inspection are widely used.

In these endoscopes, there are provided an optical endoscope for transmitting an observation image to an eyepiece through an image guide, and an image pickup device provided with a solid-state image pickup device such as a CCD at the tip of an insertion portion. There is an electronic endoscope. In these endoscopes, the insertion portion must be inserted into a small-diameter, meandering tube, and thus it has been desired to reduce the outer diameter and shorten the hard portion.

[0004] In order to reduce the outer diameter and shorten the hard portion, an optical lens, a brightness diaphragm, and the like are also used in a diaphragm device disposed at the distal end of the endoscope, for example, constituting an imaging optical system. Was reduced in diameter and thickness.

[0005]

However, since the optical lens and the aperture stop are formed thin and small in diameter, the assembling operation is complicated. In particular, FIG.
As shown in FIG. 1A, in a state where a thin objective lens 2 and a thick objective lens 3 and a thin aperture stop 4 having an opening 4a having a predetermined diameter are arranged on a lens frame 1,
The technique for bonding and fixing the thin objective lens 2 to the lens frame 1 required skill.

In other words, when the adhesive 5 having excellent fluidity is applied to the adhesive reservoir 1a for bonding and fixing, if the applied amount of the adhesive 5 is too large, the adhesive applied to the adhesive reservoir 1a is The agent 5 is used for the lens frame 1 by capillary action.
In addition to the gap between the objective lens 2 and the aperture stop, the light passes through the gap between the lens frame 1 and the objective lens 2 and flows into the gap between the objective lens 2 and the aperture stop 4 as shown in FIG. . As a result, an adhesive adhering portion 5a that causes flare is formed around the opening 4a of the aperture stop 4 as shown in FIG. 4C, or the opening 4a as shown in FIG. Is completely closed, and an adhesive sealing portion 5b is formed, causing a defect.

In order to prevent these problems, attempts have been made to fix the optical lens to the lens frame using a highly viscous adhesive, but the workability in applying the adhesive is poor and the adhesive strength is low. Will also vary.

The present invention has been made in view of the above circumstances, and when an adhesive having excellent fluidity is poured into a gap between an optical lens and a lens frame, the adhesive reaches the aperture of the diaphragm to generate flare. It is an object of the present invention to provide a compact drawing device excellent in assembling workability by reliably preventing formation of an adhesive attachment portion, an adhesive sealing portion, and the like that cause the above.

[0009]

A diaphragm device according to the present invention includes a lens frame, a plurality of optical lenses, and a diaphragm formed with an opening of a predetermined size disposed between the optical lenses.
A diaphragm device formed by fixing the optical lens to a lens frame with an adhesive, wherein at least one side surface of the diaphragm has a through hole formed with a diameter larger than an opening formed in the diaphragm. A stop member is arranged.

According to this structure, when the adhesive applied to fix the optical lens to the lens frame flows through the gap between the lens frame and the optical lens due to the capillary phenomenon, first, the optical lens and the flow stopper are stopped. It flows into the gap with the member. Next, the adhesive that has flowed into the gap between the optical lens and the flow stop member reaches the stop along the through-hole edge of the flow stop member. After this, the adhesive that reached this aperture,
It solidifies at this edge or flows into the gap between the flow stop member and the throttle to solidify. In other words, the adhesive that has flowed into the gap between the optical lens and the lens frame and has reached the stop does not reach the opening of the stop because it solidifies near the edge.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 relate to an embodiment of the present invention. FIG. 1 is a diagram illustrating a schematic configuration of a tip unit, FIG. 2 is a diagram illustrating a configuration of a diaphragm device, and FIG. 3 is a configuration and operation of a flow stop member. FIG. Note that FIG.
3A illustrates the aperture stop, FIG. 3B illustrates the stop member, FIG. 3C illustrates the operation of the stop member, and FIG. 3D illustrates the adhesive. It is a figure which shows the state when solidified.

As shown in FIG. 1, for example, a distal end unit is disposed in a distal end portion forming an insertion portion of an electronic endoscope. The tip unit includes a unit main body 20 which is a substantially pipe-shaped frame, and a light guide fiber 10 and an imaging unit 30 which supply illumination light to be housed and arranged in the internal space of the unit main body 20.

The image pickup unit 30 comprises an objective lens group 31 constituting an image pickup optical system, which is one of the optical systems, and an image pickup section 32 for converting an optical image into an image signal. A CCD 33 is arranged in the image pickup section 32,
A cover glass 34 is adhered and fixed to the imaging surface side of the CD 33. An external lead 35 extends from the CCD 33. The external lead 35 is electrically connected to a circuit board 36 on which electric components such as an IC chip 41 are sealed and mounted and a signal line 43 inserted into a signal cable 42. The connected connection board 37 is connected. Reference numeral 44 denotes a first sealing resin that protects electric components such as the IC chip 41 and the like and a connection portion with the signal line 43.

On the other hand, the objective lens group 31 includes, for example, a first lens frame 38 and a second lens frame 39, and the first lens frame 38 and the second lens frame 39 have one optical lens. An optical lens such as a first objective lens 11 formed of a flat flat plate, a field lens 40 having one end having a convex shape, a brightness stop 13, and the like are incorporated therein.

The imaging unit 30 includes the imaging unit 32
After the cover glass 34 and the field lens 40 forming the objective lens group 31 are integrally fixed, the optical image passing through the objective lens group 31 is
The first lens frame 38 and the second lens frame 39 are formed by adjusting the positional relationship and adjusting the focus so that an image is formed on the imaging surface of the first lens frame 38. The built-in components such as the imaging unit 30 and the light guide fiber 10 are fixed in the unit main body 20 in a stable state by the second sealing resin 46 filling the internal space of the unit main body 20.

Reference numeral 47a denotes a distal bending piece rotatably connected to the connecting member 45.
47c is also a bending piece connected rotatably.
Reference numeral 48 denotes a fixed tube 48a attached to the tip bending piece 47a.
The other end is a bending wire fixed to a bending operation knob (not shown), and reference numeral 49 is a guide tube through which the bending wire 48 is inserted.

As shown in FIG. 2, the first lens frame 38
One side, which is one of a first objective lens 11 having a flat wall and a thin wall, a flow stop member 14 having a through-hole 14a formed therein, a brightness stop 13 having an opening 13a, and an optical lens, is sequentially flat from the front end side. A diaphragm device is configured by disposing a thick second objective lens 12 having a flat plate and the other surface formed as a convex surface.

The aperture stop 13 is made of, for example, phosphor bronze having a thickness of 3/100 mm.
As shown in FIG. 3A, an opening 13a having a predetermined diameter is formed at the center of the aperture stop 13. On the contrary,
As shown in FIG. 2B, the flow stop member 14 is formed of phosphor bronze having a thickness of 3/100 mm, similarly to the brightness stop 13, and is formed on the brightness stop 13 at the center. A through hole 14a having a larger diameter than the opening 13a is formed.

The first objective lens 11 is connected to the first lens frame 3.
When an adhesive 16 having a high fluidity is applied to the adhesive reservoir 15 in order to fix it to the adhesive 8, the adhesive 16 flows into the gap between the first objective lens 11 and the first lens frame 38 by capillary action.

At this time, when the amount of the adhesive 16 applied to the adhesive reservoir 15 is large, the adhesive 16 flowing into the gap between the first objective lens 11 and the first lens frame 38 is As shown in (c), it flows into the gap between the first objective lens 11 and the flow stopping member 14.

Then, as shown in FIG. 2C, the adhesive 16 flowing into the gap between the first objective lens 11 and the flow stopper 14 is applied to the through hole 1 of the flow stopper 14.
4a reaches the edge portion and solidifies, while the remaining part of the adhesive 16 flows along the edge of the through hole 14a and flows into the gap between the flow stop member 14 and the brightness stop 13 to be solidified. I do.

That is, the adhesive 16 flowing into the gap between the first objective lens 11 and the first lens frame 38 out of the adhesive 16 applied to the adhesive pool 15 becomes the first objective lens 11 and the first lens A gap between the frame 38, a gap between the first objective lens 11 and the flow stopping member 14, an edge of the through hole 14a,
Since the solidification occurs in the gap between the flow stop member 14 and the brightness stop 13 (see FIG. 4D), the opening 13a of the brightness stop 13 is formed.
Can not be reached.

As described above, by disposing the flow stop member having a through-hole having a diameter larger than the opening of the brightness stop on one side surface of the brightness stop where the thin objective lens is provided, the capillary tube is provided. It is possible to prevent the adhesive flowing into the gap between the objective lens and the lens frame from reaching the opening formed in the aperture stop due to the phenomenon.

With this, when the optical lens is bonded and fixed to the lens frame without largely changing the hard length of the lens frame constituting the diaphragm device, the adhesive adheres to the opening peripheral surface of the aperture stop. In addition, since defects such as closing the openings are reliably prevented, the bonding workability and the yield rate are greatly improved.

The hole diameter of the opening 13a and the hole diameter of the through hole 14a are appropriately set depending on the fluidity of the adhesive used, the thickness or diameter of the optical member, and the like.

In this embodiment, the aperture is described as a brightness aperture. However, the aperture is not limited to a brightness aperture, and may be a field stop or the like. That is, the aperture device is not limited to the one used as the imaging optical system of the electronic endoscope.

Further, as shown in FIG. 4, when the second objective lens 12 is adhered and fixed to the first lens frame 38, when there is a possibility that the adhesive may flow, the aperture stop 13 and the second objective lens 12 may be connected to each other. An anti-flow member 14 is disposed therebetween. That is, the flow stop members 14 are arranged on both sides of the aperture stop 13.

As a result, the adhesive does not adhere to the periphery of the opening of the aperture stop or the opening is not closed by the adhesive, and the adhesive is sufficiently applied to attach the objective lens to the first lens frame. It can be easily and reliably adhered and fixed.

The first objective lens 11 and the second objective lens 12 are not limited to flat plate optical lenses. For example, as shown in FIG. 5 (a), an objective lens 11a having a flat surface formed with a concave portion 11b having a diameter φR. And so on.

At this time, the flow stop member 14 is formed with a through hole 14b having a diameter larger than the diameter of the opening 13a formed in the aperture stop 13 and the concave portion 11b of the objective lens 11a. .

That is, the diameter (φR) of the concave portion 11b
The relationship of φR <φD is set between the flow stop member 14 and the hole diameter (φD) of the through hole 14b.

As a result, the same functions and effects as those of the above embodiment can be obtained. In addition, FIG.
As shown in (b), the flow preventing member and the throttle may be integrated to form an adhesive flow prevention throttle 13A. The adhesive flow preventing aperture 13A has a large-diameter concave portion 14c and an inclined concave portion 14d formed with a large diameter with respect to the opening 13a.

Incidentally, an adhesive reservoir groove 14e may be provided as shown by a broken line in the figure. Further, the large-diameter concave portion 14c and the inclined concave portion 14d are connected to the adhesive flow preventing aperture 14A.
May be provided on both sides.

It should be noted that the present invention is not limited to only the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

[Appendix] According to the embodiment of the present invention described in detail above, the following configuration can be obtained.

(1) A lens frame, a plurality of optical lenses, and a stop formed between the optical lenses and having an opening of a predetermined size are formed, and the optical lens is fixed to the lens frame with an adhesive. An endoscope in which a flow stop member having a through hole formed to have a diameter larger than an opening formed in the diaphragm is disposed on at least one side surface of the diaphragm.

(2) The endoscope according to appendix 1, wherein the flow stopping member is disposed on a side surface of the diaphragm on the side where the adhesive is poured.

[0038]

As described above, according to the present invention, when an adhesive having excellent fluidity is poured into the gap between the optical lens and the lens frame, the adhesive reaches the aperture of the diaphragm and causes flare. It is possible to surely prevent the formation of the adhesive-attached portion, the adhesive-sealed portion, and the like that cause the problem, and to provide a small drawing device excellent in assembling workability.

[Brief description of the drawings]

FIG. 1 to FIG. 3 relate to an embodiment of the present invention,
FIG. 1 is a diagram illustrating a schematic configuration of a tip unit.

FIG. 2 illustrates a configuration of an observation optical system.

FIG. 3 is a diagram illustrating a configuration and an operation of a flow stopping member.

FIG. 4 is a diagram illustrating another configuration of the observation optical system.

FIG. 5 is a diagram illustrating another configuration of the observation optical system.

FIG. 6 is a diagram illustrating another configuration of the flow stopping member.

FIG. 7 is a diagram illustrating the configuration of a conventional observation optical system, the state of adhesive flowing in, and the effect of the adhesive on the diaphragm.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... 1st objective lens 12 ... 2nd objective lens 13 ... Brightness stop 13a ... Opening 14 ... Flow stop member 14a ... Through-hole 16 ... Adhesive

Claims (1)

[Claims] 1. An optical system comprising: a lens frame; a plurality of optical lenses; and an aperture formed between the optical lenses and having an opening having a predetermined size, the optical lens being fixed to the lens frame by an adhesive. A diaphragm device, comprising: a flow stop member having a through-hole formed in a diameter larger than an opening formed in the diaphragm, on at least one side surface of the diaphragm.