JPH01113716A - Hard electronic endoscope - Google Patents

Abstract

PURPOSE:To easily set a visual field mask to obtain an endoscope image easy to see by arranging the visual field mask in the image forming position of an objective lens system or a relay optical system. CONSTITUTION:An objective lens 7 and relay lens groups 9a and 9b are arranged in series in a lens tube 4 in an insertion part 3 of a hard electronic endoscope 1. A visual field mask 10 is provided in the image forming position before the relay lens group 9a, and a solid-state image pickup element 11 is arranged at the rear of the lens group 9a. In this constitution, light irregularly reflected from the periphery of the relay lens group or dark peripheral light is intercepted by the visual field mask 10 and a distinct endoscope image is seen in distinction from the dark part. Thus, the mask is easily set without being stuck to the image surface of the solid-state image pickup element 11 to obtain the endoscope image easy to see.

Description

[Detailed Description of the Invention] [Industrial Application Field 1] The present invention relates to a rigid electronic endoscope in which an optical image transmitted by a relay optical system is formed on an imaging surface of a solid-state imaging device. .

[Problems to be solved by conventional techniques and inventions] In recent years,
By providing an observation means in the elongated insertion section, endoscopes can be widely used to diagnose affected areas within the body without the need for incisions, and to perform therapeutic procedures using a neck tool if necessary. became.

The endoscopes include flexible endoscopes with flexible insertion sections and rigid endoscopes with rigid insertion sections.

The flexible endoscope has the advantage of being able to be inserted through a curved insertion path, while the fecal endoscope can only be inserted in a straight line, but has the advantage of being highly effective at targeting target sites. or,
A rigid endoscope can use a relay optical system as an image guide, and has the advantage of increasing resolution.

In a rigid endoscope that uses this relay optical system, by placing a field mask at the imaging position between the relay optical system and the eyepiece, it is possible to block the light rays that are diffusely reflected from the periphery of the relay lens, and to It blocks out ambient light and provides a clear image.

Incidentally, recently, various electronic scopes incorporating solid-state imaging devices such as charge-coupled devices (CODs) into endoscopes as N-image means have been proposed, for example, in Japanese Patent Laid-Open No. 61-8273, and have not yet been put into practical use. It is being done. This electronic scope has a high resolution and can record and play back images without attaching a still camera or television camera to the eyepiece, and it is easy to perform image processing such as enlarging images and comparing two images. It has the following advantages. On the other hand, instead of an eyepiece,
A rigid electronic endoscope in which the imaging surface of a solid-state imaging device is arranged at the imaging position at the rear end of the relay optical system is also disclosed in Japanese Patent Application No. 110059/1986.
This method has been proposed in Japanese Patent Application No. 110060/1983.

However, in a rigid electronic endoscope in which the image plane of a solid-state image sensor is disposed at the imaging position at the rear end of the relay optical system, if a field mask is not placed on the image plane of the solid-state image sensor, the mass;
) Although the image is blurred and a clear image cannot be obtained,
On the imaging surface of the solid-state R image element, essential optical filters such as a color mosaic filter, a crystal filter, an infrared cut filter, and a dancing image surface protective glass are attached. Difficult to place.

Furthermore, in a rigid electronic endoscope in which an imaging lens group or a beam splitter for dividing the optical path is arranged between the relay optical system and the solid-state image sensor, a field mask is arranged at the rear end of the relay optical system. In some cases, it is necessary to arrange these imaging lenses or beam splitters in series, which complicates the structure and requires a long distance between the rear end of the relay optical system and the solid-state image sensor, making operation difficult. There is a disadvantage that the part is long and large.

The present invention has been made in view of these circumstances, and it is possible to arrange a field mask without attaching the field mask to the image plane of the solid-state image sensor or increasing the size of the operation section. , blocking diffusely reflected light rays or dark ambient light, surrounding the rigid electronic endoscope image on the TV monitor with a field mask image, and clearly separating the image from the surrounding dark area covered by the field mask image. It is an object of the present invention to provide a rigid electronic endoscope that allows easy-to-see images.

[Means for Solving the Problems and Their Effects] In order to achieve the above object, the rigid electronic endoscope according to the present invention has an elongated and rigid insertion section extending forward from the main body. An objective lens system for image formation is disposed at the rear of the objective lens system, and a relay optical system is disposed behind this objective lens system for transmitting the optical image formed by the objective lens system to the rear. In this configuration, a solid-state fil image element is disposed at an imaging position, and a field mask is disposed at an imaging position of either the objective lens system/relay optical system.

With this configuration, the rigid electronic endoscope image can be surrounded by a field mask image that blocks diffusely reflected light or dark ambient light.

[Embodiment] Figures 1 and 2 relate to a first embodiment of the present invention, in which Figure 1 is a body configuration diagram showing the main parts of a rigid electronic endoscope with cutouts, and Figure 2 is a frame sequential system. FIG. 2 is an explanatory diagram showing an outline of a rigid electronic endoscope device that employs the above.

In these figures, the symbol @1 indicates a rigid electronic endoscope, with an operating section 2 that also serves as a grip on the hand side, and a linear, elongated, rigid insertion section 3 that extends forward from the operating section 2. Consisting of
A lens tube 4 and a light guide 5 made of a fiber bundle are arranged in parallel in the axial direction from the operating section 2 to the insertion section 3, and the tip of the light guide 5 is located at the light output end on the distal end surface of the insertion section 3. It becomes. On the other hand, the lens tube 4 extends to the distal end surface of the insertion section 3, and has a cover glass 6 disposed within the distal end, and an objective lens 7 disposed within the lens tube 4 behind the cover glass 6. Furthermore, a plurality of relay lens groups 9a, 9b, . A field mask 10 is located at the imaging position in front of the lens group 9a.
A solid-state image sensor 11 is disposed at an imaging position behind the rearmost relay lens group 9a. The field mask 10 may be arranged at an imaging position in front of the relay lens groups 9b, . . . other than the rearmost relay lens group 9a.

The solid-state image sensor 11 is fixed to a substrate 14 with a protective filter 12 and an infrared cut filter 13 attached to the front surface thereof, and is connected to the substrate 14 with a bonding wire (not shown). It is attached to the mm of the lens tube 4 through the lens tube 4. A large number of signal lines 16 are connected to this substrate 14.

A flexible cable 17 is connected to the rear end of the operating section 2.
For example, they are integrally connected via a connecting portion 18, and the light guide 5 and the signal line 16 extend within this cable 17. A connector 17a is provided at the end of this cable 17, and an electrical system socket 19 and a light system socket 20 are provided on this connector 17a.

The IC control device 23 has a built-in light source device 21 and a video signal processing circuit 22, and the sockets 19 and 20 of the connector 17a are connected to the electric connector receiver 24 and the light receiver 25, respectively. At the same time,
A color CRT 26 is connected as a display means.

The light source device 21 provided in the control device 23 has a second
As shown in the figure, the light source lamp 27 and the red, green, and blue three
Rotating color filter 28 consisting of primary color transmission filters
It is equipped with This rotating color filter 28 is rotatably driven by, for example, a stepping motor 29.

The illumination light from the light source lamp 27 passes through the rotating color filter 28 and is sequentially turned into light of each wavelength of red, green, and blue, and is condensed by a condensing lens 30 to guide the light guide 5 in the cable. After that, the light is emitted from the tip of the insertion section 3, and the observation site is illuminated in color plane sequentially.

The reflected light corresponding to each color of red, green, and blue from the observation site is transmitted through an objective lens and a relay lens system, and is received by an image area of an imaging chip embedded in the solid-state imaging device 11. It has become.

In the case of the frame sequential system, the output signal from the image area of the imaging chip is subjected to video signal processing as shown in FIG. 2, for example.

That is, the signals corresponding to each pixel of the solid-state image sensor 11 are sequentially output in the horizontal direction, for example, in response to a clock signal applied from the drive circuit 31. The electrical signal containing this image information is amplified by a preamplifier 32, a video signal is extracted by a sample hold circuit 33, further γ-corrected by a γ-correction circuit 34, and then converted into a digital signal by an A/D converter 35. be done. This electrical signal is switched by a multiplexer 36 in synchronization with the color sequential illumination,
R frame memory 37 that sequentially corresponds to each color of red, green, and blue
．． G frame memory 38. It is stored in the B frame memory 39. Each of the frame memories 37, 38, and 39 is read out simultaneously in the horizontal direction at a speed matched to a display device such as a color CRT monitor 26, and each of the frame memories 37, 38, and 39 is read out simultaneously in the horizontal direction.
It is converted into an analog signal at 0.41°42, R, G,
This becomes a B color signal. By inputting these R, G, and B signals to the color CRT monitor 26, the observed region is displayed in color.

In this configuration, light rays diffusely reflected from the periphery of the relay lens group or dark ambient light are blocked by the field mask 10 disposed at the imaging position in front of the relay lens group 9a,
Only clear endoscopic images enter the solid-state image sensor 11.

FIG. 3 is an explanatory diagram showing an overview of the control unit, etc. of a rigid electronic endoscope according to a modification of the first embodiment of the present invention which employs a simultaneous system.

In this embodiment, a color mosaic optical filter 44 is disposed between the solid-state image sensor 11 and the protective filter 12, which are disposed at the imaging position of the rearmost relay lens group 9a.

On the other hand, the control device 23 is provided with a mosaic process circuit 45 and a light source device 46 as shown in FIG. The light source device 46 includes a light source lamp 27 and a condensing lens 3.
It is composed of 0.

The white light emitted from the light source lamp 27 is condensed by the condenser lens 30, enters the light guide 5 made of a fiber bundle in the cable, and enters the insertion section 3.
The light is emitted from the tip and illuminates the observation area.

The white light reflected from this observation site passes through an objective lens and a relay lens system, and then passes through a protective filter 13. After passing through the infrared cut filter 12, a color mosaic optical filter 4 is applied.
4, and is separated into red, green, and blue pigments by this color mosaic optical filter 44.

The light separated into red, green, and blue pigments is received by the image guide area of the imaging chip. The electrical signal containing image information from this imaging chip is
In the case of the simultaneous system, for example, as shown in FIG. 3, video signal processing L! ! be done.

That is, signals corresponding to each pixel in the image area of the imaging chip are sequentially outputted, for example in the horizontal direction, in synchronization with a clock signal applied from the drive circuit 31. This electrical signal is amplified by a preamplifier 32 and input to a luminance signal processing circuit 47 and a color signal reproducing circuit 48. As a result, the luminance signal processing circuit 47 generates the luminance signal Y, and the color signal reproducing circuit 48 generates the color difference signals R-Y and 8-Y in time series for each horizontal line. , the white balance is compensated by the white balance circuit 49, one is directly input to the analog switch 50, the other is delayed by one horizontal line by the 1H delay line 51 and input to the analog switch 50a, and the color difference signal is input by a switching signal of a timing generator (not shown). R
-Y, BY are generated. The luminance signal Y and the color difference signals R-Y and B-Y are multiplexed by an NTSC encoder 52 and input to a color CTR monitor 26, so that the observed region is displayed in color.

FIG. 4 is a sectional view of essential parts of a rigid electronic endoscope according to a second embodiment of the present invention.

In this embodiment, in the rigid electronic endoscope of the first embodiment,
A field mask 10 is disposed at the imaging position of the objective lens 7 on the distal end side of the insertion section 3.

FIG. 5 is an explanatory cutaway view of the main parts showing the operation section side of the rigid electronic endoscope according to the third embodiment of the present invention.

In this embodiment, the operating section 54 and the infrared cut filter 1
3 and the solid-state imaging probe 11 to which the protective filter 12 is adhered
For example, a male screw formed on the outer periphery of the operating section 54 and an image capturing section 5 are connected to each other.
The connecting ring 56 is rotatably engaged with the outer periphery of the connecting ring 5, and a female thread formed on the inner periphery of the connecting ring 56 is screwed into the connecting ring 56, thereby removably connecting the connecting ring 56. A cover glass 57 is attached to a set screw 5 through an O-ring 58 in the rear end open portion formed in the operating portion 54.
A light guide cap 60 is provided on the side of the operating section 54, and by fixing the light guide 5, the rigid electronic endoscope 53 including the operating section 54 has a watertight structure. There is. - On the other hand, in front of the infrared cut filter 13, a cover glass 61 is crimped and fixed to the imaging section 55 with a set screw 63 through an O-ring 62, and on the rear end side of the imaging section 55, from the substrate 14. A cable 64 containing an extended signal line 16 is connected to the prefectural image portion 55 to form a watertight structure. Further, an O-ring 65 is disposed between the end faces of the operating section 54 and the IS section 55 so that the O-ring 65 is crimped when the two are connected.
In addition to preventing water from entering the outer surface of the cover glass 57, 61, the distance between them is R-end lens 8.
The light beam emitted from C passes through the cover glass 57.61 and the infrared cut filter 13. The solid-state image sensor 11 is adjusted to be placed at a position where it passes through the protective filter 12 and forms an image. Note that the screw 6 is inserted from the outer periphery of the connecting ring 56.
6 is threaded through 4 and abuts against the outer periphery of the image section 55. By screwing in the screw 66, the connecting ring 56 is connected to the imaging section 5.
It can be fixed to 5.

Further, a male thread is formed on the outer periphery of the light guide cap 60, and is screwed into a female thread formed on the inner periphery of a connecting ring 69 rotatably engaged with the outer periphery of the cap 68 of the light guide cable 67. , the light guide 5 and the light guide 70 in the light guide cable 67 are detachably connected so that their end faces coincide with each other. An electrical socket 19 and a light socket 20 are provided at the extended ends of the cable 64 and the light guide cable 67, and the electrical connector receiver 24 and light receiver of the control device 23 are connected to the connector receiver 25, respectively. The observation site is displayed in color by a frame-sequential control device 23. Note that a simultaneous method may be adopted by arranging the color mosaic optical filter 44.

With the above configuration, the field mask image is formed on the imaging surface of the solid-state image sensor and surrounds the endoscopic image, so that the endoscopic image and the surrounding dark area covered by the field mask image are separated. A clearly separated, easy-to-see image can be easily obtained without the troublesome task of pasting a field mask on the imaging surface.

In addition, in the third embodiment, the insertion part that requires disinfection can be separated watertight from the fixed image sensor, which is sensitive to heat, etc., so a powerful moisturizing method that can damage electronic equipment such as autoclaves can be implemented to prevent infection. A great effect can be expected. Furthermore, by preparing several types of insertion sections having different optical systems such as strabismus and side viewing, there is an advantage that one expensive imaging section can be used for various purposes.

FIG. 6 is an explanatory cutaway view of the main parts showing the operating section side of the rigid electronic endoscope according to the fourth embodiment of the invention.

In this embodiment, imaging lenses 72a and 72b are provided between the final relay lens group 9a and the solid-state image sensor 11.

72c, along with spacer tubes 73a and 73b, are fixed to a slide tube 75 from which the bottle 74 protrudes from the outer periphery, and are arranged so that they can be moved back and forth in the axial direction within the operating section 76 together with the slide tube 75. be. Bin 74 is
A straight line type 7 extending in the axial direction opened in the side wall of the operation unit 76
7 and is slidable in both the linear type 77 and the cam groove 78b to the inside of the cam m 78 b provided on the inner periphery of a cam tube 78 a rotatably locked to the outer periphery of the operating portion 76 It has been extended to A light guide base 80 to which a light guide cable 79 is connected is fixed to the front side wall of the operation unit 76, and the light guide 5 is connected to the light guide cable 79.
It extends through the light guide base 80 to the light system socket 20 provided at the rear end. Operation section 76
A substrate 14 including a solid-state image sensor 11 to which an infrared cut filter 13 and a protection filter 12 are attached is attached to the rear end.
An imaging unit 81 is connected to the imaging unit 8.
Further, a cable 64 is connected to the rear end of the board 14 with a built-in signal line 16 coming out from the board 14.

With the above configuration, even if the distance between the objective lens and the subject changes greatly, by rotating the cam tube 78a, the bottle 74 will slide within the cam groove 78b and the linear type 77, and the operating section Imaging lenses 72a and 7'2b are disposed inside 76 together with the slide tube 75.

72C is moved, and the internal mirror image is always solid-state 'rA image element 1.
The image can be formed on one imaging plane, and an easy-to-see image can be obtained in which the endoscopic image and the surrounding dark area covered by the field mask image are clearly separated.

Moreover, since there is no need to provide the field mask 10 inside the operating section 76, the structure is simplified, and the relay lens group 9a
Since the imaging lenses 72a, 72b, and 72C can be brought as close as possible to the relay lens group 9a and the solid-state image sensor 1,
1 can be shortened, making it possible to downsize the operating section 76.

FIG. 7 is a cutaway explanatory view of the main parts showing the operating section side of the rigid electronic endoscope according to the fifth embodiment of Honbatsucho.

In this embodiment, a beam splitter 83 is arranged behind the final relay lens group 9a by adhesively fixing it to the inner wall of the operating section 84, and a part of the light beam transmitted by the relay lens system is arranged with respect to the light axis. It is split into rays that travel at right angles. Infrared cut filter 13 and protection filter 12
The imaging section 85 fixing the substrate 14 containing the solid-state imaging device 11 with the solid-state imaging device 11 attached thereto is fixed to the beam splitter 83 so that the light beam split by the beam splitter 83 is focused on the imaging surface of the solid-state imaging device 11. It is arranged. The signal line 16 connected to the board 14 is connected to the light guide 5.
At the same time, it extends into the cable 17 connected to the base 86 attached to the side wall of the operating section 84 . on the other hand,
At the rear end of the operation unit 84, an eyepiece lens 87 is arranged on the optical axis that advances straight from the relay lens group 9a and the beam splitter 83.
An eyepiece section 88 is connected thereto.

With the above configuration, it is not necessary to arrange the field mask 10 between the relay lens group 9a and the beam splitter 83, and the distance between them can be made sufficiently close, and the beam splitter 83 and Since there is no need to provide two field masks 10 both between the solid stone image elements 11 and between the beam splitter 83 and the eyepiece 87, the structure of the operating section 84 can be simplified and downsized. Moreover, the field mask 10 provided within the relay lens system makes it possible to obtain an easy-to-see image in which the endoscopic image and the surrounding dark area covered by the field mask image are clearly separated.

[Effects of the Invention] As explained above, according to the present invention, the field of view mask can be disposed on the imaging surface of the solid-state image sensor or without increasing the size of the operation unit. , blocking diffusely reflected light rays or dark ambient light, surrounding the rigid electronic endoscope image on the TV monitor with a field mask image, and clearly separating the image from the surrounding dark area covered by the field mask image. This has the effect of providing an easy-to-see image.

[Brief explanation of the drawing]

1 and 2 relate to the first embodiment of the present invention, FIG. 1 is an overall configuration diagram showing the main parts of a rigid electronic endoscope with cutouts, and FIG. 2 is a rigid electronic endoscope using a field sequential method. FIG. 3 is an explanatory diagram showing an outline of an endoscope apparatus, FIG. 3 is an explanatory diagram showing a modification of the first embodiment of the present invention that employs a simultaneous system, and FIG.
5 is a cross-sectional view of the embodiment, FIG. 5 is a cutaway diagram of the main part according to the third embodiment, FIG. 6 is a cutaway diagram of the main part of the fourth embodiment,
FIG. 7 is a cutaway explanatory diagram of a main part according to the fifth embodiment. 2...Operation section 3...Insertion section 7...Objective lenses 9a, 9b...Relay lens 10...Field mask 11...Solid-state image sensor, PAL'7. . Agent: Patent Attorney Susumu Ito 1, :“
Figure 2 Figure 3 Figure 4 Soa Figure 5 Figure 6 Figure 7 Procedure Ne City official document (spontaneous) March 15, 1988 1, Indication of incident 1988 Patent Application No. 272609
No. 2, Title of the invention Rigid electronic endoscope 3, Relationship with the case of the person making the amendment Representative of the patent applicant: Satoshi Shimoyama Department 5, Date of the amendment order (voluntary) 6, Subject of the amendment The “invention” in the specification 1. In the 3rd page, line 16 of the specification, "infrared cut filter filter" should be corrected to "infrared cut filter". Masu. 2. On page 11, line 11 of the specification, "this electrical signal is" should be corrected to "this electrical signal is". 3. On page 16, line 15 of the specification, there is a ``protective filter''
" is corrected to "protection filter". Figure 4■

Claims (1)

[Claims] An elongated and rigid insertion section is provided forward from the main body, and an objective lens system for imaging is disposed at the distal end of the insertion section, and an image is formed by the objective lens system behind the objective lens system. A relay optical system is disposed to transmit an optical image rearward, and a solid-state image pickup device is disposed at the final imaging position of the optical system, and a solid-state image sensor is disposed at the final imaging position of the objective lens system/relay optical system. ,
A rigid electronic endoscope characterized by being equipped with a field mask.