JPS6188216A - Lighting device of endoscope - Google Patents

Abstract

PURPOSE:To easily vary the light distribution state of illumination light and set a desired light distribution state speedily by using a liquid-crystal cell for a lighting optical system and providing a control means for an applied voltage which varies and controls the refractive index of liquid crystal at hand. CONSTITUTION:Liquid crystal materials 26a and 26b which have the same characteristics are charged between a plano-concave lens 24 and a concave lens 25 fitted to both sides of a transparent plate 22, such as a glass plate, fixed to a frame 21 across spacers 23 and 23, and the transparent plate 22. Those liquid crystal materials 26a and 26b decrease in refractive index as the applied voltage V0 rises, and therefore the focal length of a liquid crystal lens 15 as a concave lens becomes long. Consequently, the orientation angle (projection angle) of illumination light is decreased as the applied voltage V0 is raised, and increased by lowering the applied voltage. For the purpose, the applied voltage is controlled at hand to set a desired orientation state speedily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention 1] The present invention relates to an endoscope illumination device that can set a light distribution state suitable for observation.

[Technical background of the invention and its problems] Endoscopes are generally installed at the distal end of the elongated insertion section (in addition, an illumination means is also installed to illuminate the range that can be observed by the objective optical system for observation). Being numbered.

The illumination means transmits the illumination light from the light source in the light source device through a light guide, and emits it from the output Q4 end on the distal end side of the insertion tube directly or through a light distribution lens, and illuminates the object side in the range for the observation [ihi]. It is common that the lighting is for illumination.

The illumination light that is emitted through the light distribution lens is spread out at a considerably larger angle than the viewing angle of the observation means so that it can be used in conditions that vary greatly, such as when the object distance is small or large. (T1 is done.

For this reason, for example, when you want to focus on a part of the field of view from an appropriate distance and observe it in detail, the illumination light 'M tends to be insufficient, and the illumination condition may deviate from the optimal illumination condition for each subject distance. is often the case.

For this reason, for example, as disclosed in Japanese Utility Model Publication No. 5 F3-115201, a sufficient amount of light is required at the part where the illumination tube [1-B to C1] can be inserted into the FP channel of the endoscope. Irradiating illumination light, etc. (, J, There is one that makes it visible by observation in the REIT 1゜The above illumination lamp) - (Well, it is very right Because it requires moving the probe forward and backward, it takes a long time to set the desired illumination state, and care must be taken to ensure that the illumination probe does not damage the inner wall of the body cavity when it protrudes. There are problems such as not being able to do so.

[Objective of the Invention 1] The present invention has been made in view of the above points, and an object of the present invention is to provide an illumination device for an endoscope that can be easily and quickly set to a state suitable for observing a desired region. With the goal.

[Overview of optical system] The present invention is an optical system that is disposed on the distal end side of the insertion section and uses illumination light to vary the alignment state of liquid crystal molecules by applying a voltage or the like. control) 11
If you use a liquid crystal cell that can be used, the 111 (
By providing an operating means for varying the analysis t+, the light distribution state of the illumination light can be easily varied by nJ, l'l
This allows you to quickly set the desired light distribution pattern.

[See the drawings below for examples of optical applications. ; u l, write this Σ to f, 1. I explained to myself.

Figures 1 and 2 relate to the first embodiment of the present invention.
The figure shows an endoscope equipped with the first embodiment, and FIG. 2 shows the device portion of the first embodiment shown in FIG.

The endoscope 1 provided with the first embodiment includes a flexible and elongated insertion section 2, and an eyepiece section 3 connected to the rear end side of the insertion section 2.
, a light guide cable 4 extending from the eyepiece 3, and a light guide cable 4 to which the light guide cable 4 is detachably attached.

The distal end side of the insertion section 2 is connected to the distal end (1?i) using a metal member or the like.
An objective lens system 7 for imaging is housed inside, and an image transmission guide 8 (one stage for image transmission) is inserted so that its front end faces the focal plane of the objective lens system 7. There is. However, by the image kite 8, the image of the object such as the buttock formed on its front end is transmitted to the eyepiece section 3 side, where the rear end is fixed, and can be observed through the eyepiece lens 9. An observation optical system (observation means) is configured.

Note that the image kite 8 is formed of a flexible optical fiber sheath (fiber bundle).

On the other hand, a light source lamp 11 is housed in a light source device 5 that constitutes an illumination means (1η), and this illumination light is reflected by a reflecting mirror 12 to become a substantially parallel beam of light, and a condenser lens 13'c-
A light guide 1 composed of a fiber bundle is focused at an appropriate angle and passed through the guide cable 4 from the light guide 1.
The light is irradiated onto the incident end face attached to the light source device 5, which is connected to the light source 4. Therefore, the illumination light irradiated onto this incident end surface is emitted from the front end of the light guide 14 inserted through the insertion section 2.
The illumination light emitted from rJ q1 and then emitted from this output end after being expanded at an appropriate angle is further irradiated onto the object side through the liquid crystal lens 15 that constitutes the light distribution lens in front of it. It has become so.

As shown in FIG. 2, the liquid crystal lens 15 is an AC/A
The AC output voltage of the CD converter 16 is configured to be variably divided and applied via a variable resistor (device) 17, and this variable resistor 17 is The applied voltage Vo can be easily varied by rotating the knob 18 provided on the circumference JU of the eye part 3 or the eyepiece part 3. Depending on this applied voltage (value) Vo, the liquid crystal molecules The liquid crystal lens 15 has a structure as shown in FIG. 2, for example, in which the orientation state of the liquid crystal lens 15 is varied so that its till analysis;

A plano-concave lens 24 and a concave transparent plate are attached to opposite sides of the transparent plate 22 with spacers 23 and 23 interposed on both sides of the glass plate blade fixed to the frame 21. or concave lens 25], the same 11i□
liquid crystals 26a and 26b are sealed. Above liquid crystal 2
For 6a and 26b (-1, for example, MEE or [Yo PC
B-7 ticks: 1) One item is used.

In each hill having 14 liquid crystals 26a and 26b, each opposing surface, that is, both surfaces of the inner transparent slope 22, the inner surface of the plano-concave lens 24, and the inner surface of the concave lens 25 has 3n 02, etc. h L, transparent electrode 27 a,
27b, 28a, and 28b are installed.

Both of the outer sides 14i28a and 28b are electrically connected to each other by a lead wire or the like and connected to a ground terminal. Further, both the inner electrodes 27a, 27b are also electrically connected to each other and connected to the variable resistor 17 via a lead wire inserted through the insertion portion 2, and the voltage applied between the electrodes 27a, 28a; 27b, 28b. V. A liquid crystal lens 15 is constructed in which the alignment state of liquid crystal molecules is varied and the focal length is variably controlled.

It should be noted that each liquid crystal 26a, 26b changes when no voltage is applied (, ↓, tilt).
l + direction or arrow direction △ in Figure 2, and direction B that overlaps with this direction A. How r u b l) i n g
In each orientation direction, B is orthogonal to the direction of incident light. In this way, a variable focal length lens that does not require the use of a deflection root is constructed.

That is, the incident light can be decomposed into two orthogonal polarization components, for example, the alignment direction of the arrow B in the liquid crystal 26b in FIG. 2 and the alignment direction of the arrow A in the liquid crystal 26a. First, when a polarized light component parallel to the orientation direction of arrow B of the liquid crystal 26'b, which is one component of the incident OJ light, is incident, this light beam component becomes an extraordinary light beam with respect to the liquid crystal 26b. Therefore, if a voltage is applied to the liquid crystal 26b in this state,
Since the liquid crystal molecules gradually change their orientation toward the electric center of gravity in response to the voltage, the refractive index of the liquid crystal 26b changes continuously with respect to the extraordinary light component, and the effect of changing the focal length is I will receive it. Since the extraordinary light component for the liquid crystal 26b becomes the ordinary light component for the other liquid crystal 26a, the apparent refractive index hardly changes and the effect of changing the focal length is hardly lost. (For Jokou, Denbai J, Ruku 11i
1' becomes 1 (less than 1).Therefore, you can almost go straight.

On the other hand, the large sword light component of Mo-no-j, that is, the component corresponding to ordinary light (in the liquid crystal 26b), is
The refractive index of ) hardly changes and is not affected by the effect of changing the focal length, but in product 26 a, the component equivalent to 1 extraordinary light changes / x When extraordinary light enters the liquid crystal 26 b (
Similar to the above), the apparent refractive index changes and the effect of changing the focal length is affected. By the way, both liquid crystals 26a
, 26b is applied with a rotating voltage VO, so that the effect of varying the focal length by 3 equal to N is exerted, especially 41. Therefore, by turning the optical axes of these liquid crystals 26a and 26b so that they are orthogonal to each other, the lens can operate as a lens with a variable focal length even when polarized in any direction.
As a result, a lens has been realized in which the focus button can be adjusted independently of the polarization direction of light without using a polarizing plate. In other words, without using a white board, you can use white f!
? ! We have achieved a bright lens that is highly efficient in using natural light that is not polarized.

The refractive index of the liquid crystals 26a and 26b decreases as the applied voltage VO increases, and therefore the C liquid crystal lens 1
The focal point rl' ld[ as a concave lens of No. 5 becomes longer. That is, as the applied voltage VO is increased, the orientation angle (output angle) of the illumination light is narrowed, and when the applied voltage is increased by a small amount, the orientation angle can be widened.

Therefore, for example, if you normally use a wide magnification to illuminate the outer periphery of the field of view so that it does not get dark, and if you wish to observe a part of the field of view in more detail, you can change that part of the field of view. The angle of expansion, that is, the angle of emission, is narrowed down by increasing the applied voltage VO.
Provides sufficient illumination light for more detailed observation. In addition, in the case of short distances, the application 'jt11f can be applied even under lighting conditions where the conventional example would not be able to sufficiently diffuse the light.
By increasing the size, it can be expanded more widely.

In these cases, the illumination range of the illumination light can be varied simply by rotating the eyepiece 8113 or the knob 18 provided around it, and the illumination intensity per medium area can be adjusted by the 'nJ variation. Since the intensity can be adjusted to 11, it is possible to set the black intensity suitable for observation for the observation site. Therefore, in the case of the conventional example, even at a distance where the illumination light speed tends to be insufficient due to excessive expansion, it is possible to observe by 30 minutes, and the burden of moving the endoscope can be reduced.

FIG. 3 shows the distal end side of an endoscope according to a second embodiment of the present invention, and FIG. 4 shows an enlarged view of a liquid crystal lens housed in the distal end side.

The liquid crystal lens 31 forming the illumination means of the second embodiment is
Like the liquid crystal lens 15 in the first embodiment, it is housed on the distal end side of the insertion section 2 of the endoscope 1.

The liquid crystal lens 31, as shown enlarged in FIG.
Transparent plates 33 and 34 are placed on both sides of the central transparent plate 32, facing each other with spacers 35 and 35 interposed therebetween, and a liquid crystal 35 is placed between these jΔ bright plates 32 and 33:32 and 34.
a and 35b are enclosed.

In addition, the inner surface of J'3 on both outer transparent plates 33 and 34 has a Fresnel (14 included) formed in the shape of a serrated surface.
? The liquid crystals 35a and 35b sealed here are designed so that when a voltage is applied, the liquid crystal molecules along the slope can respond quickly. still,'? ! 1ro 36a,
36b, 37a, 37b are electrically connected, and the code 3
8 is a concave lens.

The rest of the structure is the same as that of the first embodiment.

1-2 Since the liquid crystal lens 31 in the second embodiment has a Fresnel structure, it is easy to orient the liquid crystal molecules, and the response to the applied voltage VO is good. Also, LCD 3
Depending on the voltage applied to 5a, 35b, liquid crystal 35a,
Since the refractive index of 35b changes, the center direction of the emitted illumination light may be directed diagonally upward ( ) or substantially forward as shown by arrow C in the figure, for example.
It is now possible to (For application type 1.f, if V O is small, the angle of inclination to the upper side becomes large) That ll! j
(, l. It has the same effect as the first embodiment described above.

FIG. 5 does not show a third embodiment of the invention.

In the third embodiment (a3) of the endoscope 41, the f-mage guide 8 is not used, but the solid-state Katsuko 42 is used.

A liquid crystal lens 35 in the second embodiment is housed in front of the light guide 14. Further, a temperature sensor 43 is attached to this liquid crystal lens 35 in order to constitute means for compensating for temperature factors, and this temperature measurement signal is inputted to a correction circuit 44 to generate a signal for compensating for changes in refractive index caused by thirst 11ff. The output is input to one side of the subtracter 45, and a voltage set by the variable resistor 17 (if edge correction (IC+) is added to maintain the refractive index at a predetermined value.

As shown by the broken line, the correction circuit 44 takes in the set voltage of the variable resistor 17 as a control signal, and maintains it at a predetermined value over a wide temperature range and a wide range of focal length changes. be able to.

According to the third embodiment, the state of the illumination light output optical system is always set in the ship in consideration of the influence of the T temperature caused by the illumination light and the change in the ambient temperature 1σ. can be done.

In addition, it should be noted that, not limited to the above-mentioned ones, for example, the liquid crystal lens 5° 1: Isuru/, the structure of the liquid crystal 26a, The housing portion (cell) may be shaped so that 26b has a concave lens shape or a convex lens shape, or the concave lenses 24, 25 or the transparent plates on both sides can be shaped like convex lenses.Also, FIG. The transparent plate 34 can also be made into a concave lens shape or a convex lens shape, etc. In FIG. 4, the two serrated surfaces on the left have a symmetrical 414 shape; It may be the same, or it may be other sin λ1.

Furthermore, in the above description, the light distribution state of the illumination light is variably controlled by varying the applied voltage and changing the refractive index of the liquid crystal lens or liquid crystal cell.
It is also possible to variably control the angle 1fi-<° by varying the frequency of the applied voltage, or both can be made variable.
A wide range of i + J changes to make it look like a monkey, and - C monkey. In addition, if you raise the kidney 1 and control II, you can beat the monkey with b.

In addition, the means for varying the refractive index by varying the applied voltage etc. is not limited to a variable resistor, and the first stage of operation at - is 131 [IiJ It can be structured so that it can be operated by a radio foot switch, etc.

Also, the electric potential of the above applied voltage! I! is not limited to converting a commercial AC power supply into an AC voltage of a predetermined frequency Hy or a variable frequency;
C] You may use a hat using Nhaata.

In addition, the 1J optical system that changes the light distribution shape] 81 by 1 is dk
It may be combined with not only a quality lens but also a normal lens or a transparent ceramic lens whose refraction and f-line can be varied by applying voltage.

In addition, the light source for transparency is not limited to one that is located in a light source device external to the endoscope insertion section; for example, an illumination light source such as a light emitting diode or lamp may be installed at the distal end of the insertion section, and a liquid crystal display may be installed in front of the endoscope. It is of 1η construction (with a cell or liquid crystal lens installed) and is good.

<; J5, the present invention is limited to the direct view type, and is applicable only to the F side view navel or the 1:1 view I'll, which is used for 1 baby mirror and 1 side view.

For example, in 1911, it is not limited to the surface electrodes provided on the small poles 27a and 27b. An electrode that has been divided into multiple parts, such as division, can be divided into multiple parts using ':Q + F.
1141 that allows you to select a wider range of light distribution conditions by applying different voltages to the father's electrodes? It can also be used as a lighting means.

[Effects of the Invention] As described above, according to the present invention, the illumination optical system extends from the distal end side of the insertion portion of the endoscope to the object side;
(1) If a mirror is used, the refractive index of the liquid crystal can be variably controlled.)
The neutral force 1 can be adjusted by varying the applied voltage or the voltage that can be applied to the
1, it is possible to quickly set the illumination state suitable for observing the target region of interest with a simple operation.

[Brief explanation of the drawing]

1 and 2 relate to a first embodiment of the present invention, FIG. 1 is a schematic configuration diagram of an endoscope equipped with a first practical IM example, and FIG. 2 is a summary of the first embodiment. The explanatory diagrams, FIGS. 3 and 4, showing the vicinity of the liquid crystal lens, which is the main part, relate to the second embodiment of the present invention.
Fig. 3 is a cross-sectional view showing the distal end of the insertion section in the second embodiment of the endoscope; Fig. 4 is an enlarged cross-sectional view of the liquid crystal lens portion in Fig. 3; It is an explanatory diagram showing the - part of the third embodiment of the invention. 1... Endoscope 2...1 Application part 3...1
8111N section 5...Light source device 7...Objective lens system 8...Image guide 14...Light guide 15. ... Mouth J resistance 18 ... Knob 21 ... Rule-lx
22.32...; Δ closing plate 24.2! i...Concave lens 26a, 26b, 3
Chive +3 1 J 5 b...i
l'2 products 27a, 27b, 28a, 28b, 36F3
．． 3 (31), 37 a, 37 b-Lightning 1 mountain 4
2...Solid Fri steam j stop completed 44...t+ti positive [)1 route 4 boat)...loaded (
) Device Agent 5″?Built-IJ'n??! Inside Susumu Co., Ltd.

Claims (2)

[Claims] (1) In order to illuminate the object that can be imaged by the imaging optical system installed at the distal end of the insertion section of the endoscope, light is transmitted through the light distribution lens installed at the distal end of the insertion section. In the illumination means for emitting illumination light, a liquid crystal cell is used in which at least a part of the light distribution lens is sealed with a liquid crystal, and a refractive index variable control means for the liquid crystal in the liquid crystal cell is used, and the variable control means is operated. 1. An illumination device for an endoscope, characterized in that the illumination device for an endoscope is provided with means to make the light distribution state of illumination light variable controllable. (2) The illumination device for an endoscope according to claim 1, wherein the refractive index variable control means is comprised of a means for varying the value of the voltage applied to the liquid crystal or the frequency of the applied voltage.