JP2001190488A - Electronic endoscope switchable between normal light illumination and special wavelength light illumination, and rotary primary color filter and shutter used therein - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Not only can normal light illumination and special wavelength light illumination be alternately switched for the same subject to perform diagnosis and diagnosis, but also the operability of the scope itself is normal light even during special wavelength light illumination. Provided is an electronic endoscope that is substantially the same as in the case of illumination. A pixel signal obtained by an image sensor of a scope of an electronic endoscope is output as a video signal after being appropriately processed by an image signal processing unit. A light guide cable 18 is passed through the scope to guide illumination light for illuminating the front of the distal end of the scope, the proximal end of which is optically connected to a lighting device in the image signal processing unit. The lighting device includes a normal light source 24 and a special wavelength light source 26.
And light source switching means 32 for selectively guiding one of the normal light from the normal light source and the special wavelength light from the special wavelength light source to the proximal end face of the light guide cable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a scope, an image sensor provided at a distal end of the scope, and an image signal processing unit connected to a proximal end of the scope. An electronic endoscope that outputs the obtained pixel signal as a video signal after being appropriately processed by an image signal processing unit, and switches between white light illumination, i.e., normal light illumination and special wavelength light illumination, when imaging with an imaging sensor. The present invention relates to a rotary primary color filter and shutter that can be used in such an electronic endoscope.

[0002]

2. Description of the Related Art As is well known, in an electronic endoscope as described above, an image sensor is a solid-state image sensor such as a CCD (char).
The image sensor includes an objective lens system. A light guide cable made of an optical fiber bundle is inserted into the scope, and the light guide cable is a white light source lamp such as a halogen lamp or a xenon lamp provided in the image signal processing unit when the scope is connected to the image signal processing unit. Optically connected to Thus, when the scope is inserted into the body cavity of the patient, the front of the objective lens system at the distal end is illuminated with the illumination light emitted from the distal end face of the light guide cable in the scope, thereby imaging the subject. An image is formed as an endoscope image on the light-receiving surface of the sensor, where it is photoelectrically converted as a pixel signal for one frame. The pixel signals for one frame are sequentially read from the image sensor and sent to the image signal processing unit, where they are appropriately processed and then output as video signals from the image signal processing unit. The video signal is sent to a TV monitor device, where the endoscope image is reproduced on the TV monitor device.

[0003] In recent years, in the field of electronic endoscope systems, attempts have been made to use special wavelength light as illumination light for diagnosis or treatment. As an example of diagnosis using illumination of special wavelength light, attempts have been made to use ultraviolet light as illumination light for early detection of cancer tissue. It is known that, when ultraviolet light is illuminated on a body tissue, fluorescence is emitted from the tissue, and the emission intensity of the fluorescence is stronger in healthy tissue than in cancer tissue. By illuminating the body tissue with ultraviolet light and observing the emission intensity of the fluorescence, it is possible to detect cancerous tissue at an early stage. On the other hand, as an example of treatment by illumination of special wavelength light, it is known to perform heat treatment by irradiating an affected part with infrared rays.

In order to perform the special wavelength light illumination in the same manner as the normal light illumination, that is, the white light illumination, a special wavelength light source and a light guide cable for guiding the special wavelength light to the distal end of the scope are separately required. However, as a design problem of the scope, it is impossible to provide both the light guide cable for the special wavelength light and the light guide cable for the normal light in the scope.

Therefore, conventionally, it has been proposed to perform special wavelength light illumination using a treatment tool insertion passage provided in a scope. That is, the treatment tool insertion passage is used for, for example, inserting a forceps as a treatment tool to protrude from the distal end of the scope and collecting a sample of a body tissue, or the like. A special wavelength light illumination is intended to be performed by inserting a light guide cable for special wavelength light illumination. Of course, in that case, the proximal end of the light guide cable for special wavelength light illumination is optically connected to a special wavelength light source such as an ultraviolet light source or an infrared light source. It has also been proposed to use two electronic endoscopes, an electronic endoscope having a normal light source and an electronic endoscope having a special wavelength light source.

[0006]

In the former case in which the light guide cable for special wavelength light illumination is inserted into the treatment tool insertion passage of the scope, the normal light illumination and the special wavelength light illumination are alternately performed on the same subject. There is an advantage that the diagnosis and diagnosis can be performed by switching to, but at the special wavelength light illumination, the operator of the electronic endoscope not only operates the scope itself but also operates the light guide cable for the special wavelength light illumination. Therefore, there is a problem in that the scope operation under the special wavelength light illumination is complicated and troublesome as compared with the normal light illumination.

On the other hand, in the latter case using two electronic endoscopes, an electronic endoscope having a normal light source and an electronic endoscope having a special wavelength light source, the operation itself of both scopes is performed separately. Since it is performed individually, the operability of each scope is not particularly problematic, but the diagnosis and diagnosis cannot be performed on the same subject by alternately switching between normal light illumination and special wavelength light illumination. In the latter case, another electronic endoscope is required only for examination / diagnosis using special wavelength light illumination, so that the cost for diagnosis / diagnosis using special wavelength light illumination is high. The sticking point is also a problem.

Accordingly, it is an object of the present invention not only to perform diagnosis and diagnosis by alternately switching between the normal light illumination and the special wavelength light illumination for the same subject, but also to improve the operability of the scope itself even during the special wavelength light illumination. It is an object of the present invention to provide an electronic endoscope that is configured to be substantially the same as in the case of ordinary light illumination.

Another object of the present invention is to provide a rotary primary color filter and shutter which can be used in an electronic endoscope as described above.

[0010]

According to a first aspect of the present invention, an electronic endoscope includes a scope, an imaging sensor provided at a distal end of the scope, and a proximal end of the scope. A pixel signal obtained by the image sensor is appropriately processed by the image signal processing unit and then output as a video signal. The electronic endoscope according to the present invention further includes a light guide cable inserted through the scope to guide illumination light for illuminating the front of the distal end of the scope, and an illumination provided in the image signal processing unit. A proximal end of the light guide cable is optically connected to the illumination device when the scope is connected to the image signal processing unit. According to the present invention, in such an electronic endoscope, the illumination device selectively selects one of the normal light source, the special wavelength light source, and the normal light from the normal light source and the special wavelength light from the special wavelength light source. Light source switching means for guiding to the proximal end face of the light guide cable.

[0011] In a preferred embodiment of the electronic endoscope according to the present invention, the light source switching means moves the light deflecting means between a first operating position and a second operating position. And a moving mechanism. The light deflecting means guides the normal light from the normal light source to the proximal end face of the light guide cable at the first operating position, and the light deflecting means intercepts the normal light from the normal light source and sets the special wavelength at the second operating position. It is configured to direct the special wavelength light from the light source to the proximal end face of the light guide cable.

In a preferred embodiment of the electronic endoscope according to the present invention, a rotary primary color filter / shutter is provided between a proximal end face of a light guide cable and the light source device, and the rotary primary color filter is provided. A moving mechanism for moving the filter / shutter between the first operating position and the second operating position; When the normal light from the normal light source is guided to the proximal end face of the light guide cable, the rotating primary color filter / shutter is placed in the first operating position, and the proximal end face of the light guide cable is at the proximal end face of the light guide cable. When the normal light is incident on the rotating primary color filter and shutter as three primary colors at predetermined time intervals, and when the special wavelength light from the special wavelength light source is guided to the proximal end face of the light guide cable, the rotating three primary colors are used. The filter / shutter is placed in the second operating position, at which time the special wavelength light from the special wavelength light source is made incident on the proximal end face of the light guide cable at predetermined time intervals.

According to the second aspect of the present invention, as the above-described rotary primary color filter / shutter, the disk elements and the disk elements are alternately arranged at predetermined intervals along the circumferential direction of the disk elements. There is provided an image display device including a color filter of three primary colors and three light-shielding regions, wherein at least one of the light-shielding regions extends radially outward, and the extended portion functions as a rotary shutter.

In such a rotary three-primary-color filter / shutter, preferably, only one of the three light-shielding regions extends radially outward. In such a case, the reading of the three primary color pixel signals read from the imaging sensor during normal light illumination and the reading of the single color pixel signal read from the imaging sensor during special wavelength light illumination are performed at different timings.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an electronic endoscope according to the present invention will be described with reference to the accompanying drawings.

Referring to FIG. 1, an electronic endoscope according to the present invention is schematically illustrated as a block diagram. The electronic endoscope comprises a scope 10 consisting of a flexible conduit, the proximal end of which is connected to a suitable connector means (not shown).
Image signal processing unit 1 called processor via
2 is detachably connected. The distal end of the scope 10 is provided with a solid-state imaging device such as a CCD (charge-co
An imaging sensor 14 including an imaging device is provided, and the imaging sensor 14 includes an objective lens system 16 combined with the CCD imaging device.

An illumination light guide cable 18 composed of an optical fiber bundle is inserted through the scope 10, and the distal end of the light guide cable 18 extends to the distal end of the scope 10. An illumination light distribution lens 20 is incorporated at a distal end surface of the light guide cable 18, and a suitable connection adapter 22 is attached to a proximal end of the light guide cable 18, and the connection adapter 22 is connected to the image signal processing unit 12. When the scope 10 is connected, the light guide cable 18 is connected to a connection socket (not shown) provided on an outer wall of the image signal processing unit 12, and a lighting device provided in the image signal processing unit 12 at this time. Optically connected to In FIG. 1, a part of the light guide cable 18 is schematically shown by a two-dot chain line for convenience of illustration.

The illumination device in the image signal processing unit 12 includes a normal light source, that is, a white light source and a special wavelength light source. In this embodiment, the white light source is a white light lamp 24 such as a xenon lamp or a halogen lamp. The wavelength light source is an ultraviolet (UV) lamp 26. As shown in FIG. 1, in the present embodiment, the white light lamp 24 is aligned so as to face the proximal end face of the light guide cable 18, and a condenser lens 28 is interposed therebetween,
The condensing lens 28 is used for condensing the white light emitted from the white light lamp 24 on the proximal end face of the light guide cable 18. UV lamp 26 is white light lamp 2
The ultraviolet rays are arranged between the focusing lens 4 and the condenser lens 28, and the direction of emission is perpendicular to the optical axis of the condenser lens 28.

The illumination device in the image signal processing unit 12 includes a light source switching means 30.
Reference numeral 0 denotes a mirror 32 functioning as a light deflecting member, and a moving mechanism 34 for moving the mirror 32 between a first operating position and a second operating position. At an angle of 45 °. In FIG. 1, the mirror 32 is shown in the first operating position.

Referring to FIGS. 2 and 3, the relative position of the mirror 32 with respect to the white light lamp 24 and the ultraviolet lamp 26 is shown in detail. In FIG. 2, as in FIG. In FIG. 3, the mirror 32 is shown in the second actuated position. When the mirror 32 is in the first operating position, the white light emitted from the white light lamp 24 is guided to the condenser lens 28. When the mirror 32 is moved from the first operating position to the second operating position, that is, when the mirror 32 is interposed between the white light lamp 24 and the condenser lens 28, the white light lamp 2
At the same time, the white light from 4 is blocked and the ultraviolet light from the ultraviolet lamp 26 is reflected by the mirror 32 and guided to the condenser lens 28. In short, the light source is switched by appropriately moving the mirror 32 between the first operating position and the second operating position, and one of white light and ultraviolet light is used as illumination light.

Referring to FIG. 4 and FIG. 5, a specific configuration of the moving mechanism 34 constituting a part of the light source switching means 30 is shown. The moving mechanism 34 includes a rectangular frame 34a appropriately fixed and supported by an internal frame structure (not shown) of the image signal processing unit 12, and a ball rotatably supported along a longitudinal axis of the rectangular frame 34a. A screw 34b is provided, and a movable plate member 34c is screwed to the ball screw 34b. An electric motor (for example, a stepping motor or a servomotor) 34 is provided on the top of the rectangular frame 34a.
d is installed, and the output shaft of the electric motor 34d is connected to one end or upper end of the ball screw 34b, whereby the ball screw 34d is driven to rotate. As is clear from FIG. 5, both side walls of the rectangular frame 34a are
c are slidably received in grooves formed at both ends of the electric motor 34d.
When the movable plate member 34c is driven to rotate, the movable plate member 34c is moved upward or downward along the ball screw 34b according to the rotational drive direction.

As is apparent from FIGS. 4 and 5, a mirror 32 is fixed to the front side of the movable plate member 34c so as to form an angle of 45 ° with the optical axis of the condenser lens 28. As the plate member 34c moves up and down, the mirror 32 also moves up and down, whereby the mirror 32 is moved between the first operating position and the second operating position. As shown in FIG. 4, in order to define a first operating position and a second operating position of the mirror 32, a first contact is provided on each of the upper end and the lower end of one of the side walls of the rectangular frame 34a. switch 36 ₁ and the second contact switch 36 ₂ is disposed, whereas ₂ first detecting dog 38 ₁ and the second detection dog 38 is provided on each of the upper and lower surfaces of the corresponding end of the movable plate member 34c Can be When the first detection dog 38 ₁ touches the first contact switch 36 ₁ while the electric motor 34 d is driven to move the movable plate member 34 c upward, the first contact switch 36 _1
1 is turned on, and at this time, the drive of the electric motor 34d is stopped, so that the mirror 32 is kept at the first operating position. Further, when the electric motor 34d is driven so as to move the movable plate member 34c on the lower side, when the second detection dog 38 ₂ touches the ₂ second contact switch 36, the second contact switch 36 ₂ Is turned on,
At this time, by stopping the driving of the electric motor 34d, the mirror 32 is kept at the second operating position.

Referring back to FIG. 1, the illumination device in the image signal processing unit 12 further includes a stop 40, which is located between the proximal end face of the light guide cable 18 and the condenser lens 28. To be interposed. The aperture 40 itself is well known in the art, and its opening is controlled by an actuator 42, whereby the amount of illumination light incident on the proximal end face of the light guide cable 18, that is, the amount of illumination light is appropriately adjusted.

The electronic endoscope system shown in FIG. 1 employs a frame sequential method to obtain a full-color image during normal light illumination, that is, white light illumination, while obtaining a monochromatic image during ultraviolet light illumination. Is done. For this purpose, a rotary primary color filter / shutter 44 is interposed between the proximal end face of the optical cable 18 and the stop 40. As shown in FIG. 6, in the present embodiment, the color filter / shutter 44 comprises a disc element, and the disc element includes a red filter element 44R and a green filter element 44G.
And a blue filter element 44B, each of which is in the form of a sector. The color filter elements 44R, 44G and 44B are arranged along the circumferential direction of the disk element so that their centers are at an angular interval of 120 °, and a light-shielding area is provided between two adjacent color filter elements. 44S. As is clear from FIG. 6, the light-shielding region 44S projects radially outward in a sector shape, and the region between two adjacent sector-like protrusions is an open region, that is, an exposure region 44E.

As shown in FIG. 1, a rotary primary color filter / shutter 44 is mounted on an output shaft of an electric motor 46 such as a stepping motor or a servo motor.
It is rotated at a predetermined rotation frequency. The rotation frequency of the color filter / shutter 44 is equal to T which is used in the electronic endoscope.
It is determined according to the V-video reproduction method. For example, NTSC
When the PAL system is adopted, the rotation frequency is appropriately determined according to the specification. However, the rotation frequency is typically 30 Hz. The frequency is appropriately determined according to the specification, but is typically 25 Hz.

Rotating three primary color filters and shutter 4
4 is moved between a first operating position and a second operating position, and such movement of the color filter / shutter 44 is performed by mounting an electric motor 46 on a moving mechanism 48. Referring to FIGS. 2 and 3, a color filter and shutter 44 for the proximal end of the light guide cable 18 is shown.
2, the color filter and shutter 44 is shown in a first operating position, and in FIG. 3, the color filter and shutter 44 is shown in a second operating position. Such movement of the color filter and shutter 44 is linked with the movement of the mirror 32 described above.

More specifically, as is apparent from FIG. 2, when the mirror 32 is located at the first operating position, that is, when the normal light illumination by the white light lamp 24 is selected, the color filter and the shutter are used. 44 placed in a first operating position, the proximal end face of the case the light guide cable 18 takes the relative position shown for the color filter and a shutter 44 with reference numeral 18 ₁ 6. That is, the proximal end face (18 ₁ ) of the light guide cable 18 is included in the rotation area of the three primary color filter elements (44R, 44G and 44B). In the clockwise direction, red light, green light and blue light are sequentially incident on the proximal end face of the light guide cable 18 at predetermined time intervals. In short, when the normal light illumination by the white light lamp 24 is selected, the three primary color lights are repeatedly emitted from the distal end of the light guide cable 18 in the order of red light, green light and blue light at predetermined time intervals. .

On the other hand, as is apparent from FIG.
2 is in the second operating position, i.e. when ultraviolet illumination by the ultraviolet lamp 26 is selected,
Color filters and shutters 44 are placed in the second operating position, the proximal end face of the case the light guide cable 18 takes the relative position shown for the color filter and the shutter 44 by the reference numeral 18 ₂ in FIG. 6. That is, the proximal end face of the light guide cable 18 (18 ₂₎ is included in the rotation area of the exposed region 44E, UV the proximal end face of the case the light guide cable 18 is caused to sequentially incident at a predetermined time interval. In short, when the ultraviolet illumination by the ultraviolet lamp 26 is selected, ultraviolet light is repeatedly emitted from the distal end of the light guide cable 18 at predetermined time intervals.

Referring to FIGS. 7 and 8, the rotary primary color filter / shutter 44 is moved between the first operating position and the second operating position.
The specific structure of the moving mechanism 48 for moving the moving mechanism 48 to and from the operating position is shown. As in the case of the moving mechanism 34 of the mirror 32, the moving mechanism 48 is also a rectangular frame 48a fixedly supported as appropriate to the internal frame structure of the image signal processing unit 12.
And a ball screw 48b rotatably supported along the longitudinal axis of the rectangular frame 48a. A movable block member 48c is screwed to the ball screw 48b. An electric motor (for example, a stepping motor or a servomotor) 48d is provided at the bottom of the rectangular frame 48a, and the output shaft of the electric motor 48d is a ball screw 48b.
Is connected to one end, i.e., the lower end, so that the ball screw 48d is driven to rotate. As is clear from FIG. 8, both side walls of the rectangular frame 48a are
c are slidably received in grooves formed at both ends of the electric motor 48d.
When driven to rotate by the movable block member 48
c is moved upward or downward along the ball screw 48b in accordance with the rotational driving direction.

As is apparent from FIGS. 7 and 8, an electric motor 46 for rotatably holding the rotary color filter and shutter 44 is fixedly supported on the front side of the movable block member 48c. Three primary color filters / shutters 44 in accordance with the vertical movement of
Also moves up and down, whereby the color filter / shutter 44 is moved between the first operating position and the second operating position. As shown in FIG. 7, in order to define the first operation position and the second operation position of the color filter / shutter 44, first and second lower end sides of one side wall of the rectangular frame 48a are respectively provided. 1 contact switch 50 ₁
And second contact switches 50 ₂ are arranged, whereas the rod-shaped detecting dog 52 is attached to the corresponding side wall end face of the movable block member 48c. Electric motor 48d
There when driven to move the movable block member 48c on the upper side, the upper end of the rod-shaped detecting dog 52 touches the first contact switch 50 _1, the first contact switch 50 ₁ is turned on, the At this time, by stopping the driving of the electric motor 48d, the color filter / shutter 44 is kept at the first operating position. Also,
When the electric motor 48d is driven to move the movable plate member 48c downward, the rod-shaped detection dog 5
2 touches the second contact switch 50 ₂ ,
Contact switch 50 ₂ is turned on, by stopping the driving of the time motor 48d, the color filter and the shutter 44 is fastened to the second operating position.

When the mirror 32 and the rotary primary color filter / shutter 44 are respectively located at the first operating position, the electronic endoscope selects the normal light illumination mode as the illumination mode. Normal light, ie, white light, is incident on the proximal end face of the light guide cable 18.
On the other hand, when the mirror 32 and the rotary primary color filter / shutter 44 are respectively located at the second operating position,
In the electronic endoscope, the ultraviolet illumination mode is selected as the illumination mode.
UV light is incident on the proximal end face of the.

When the normal light illumination mode is selected, the rotary primary color filter / shutter 44 functions as a rotary color filter. At this time, when the color filter / shutter 44 is rotated at, for example, a rotation frequency of 30 Hz (NTSC system). ), The time required for one rotation is about 33.3ms
(1/30 sec), and each color filter element (44R, 44
G, 44B) is approximately 33/6 ms. From the distal end surface of the light guide cable 18, red light, green light, and blue light are sequentially emitted for approximately 33/6 ms every 33.3 ms (1/30 sec), so that the subject can emit three primary colors, that is, red light,
The light is sequentially illuminated with the green light and the blue light, and is sequentially formed on the light receiving surface of the image sensor 14 by the objective lens system 16. The image sensor 14 photoelectrically converts the optical subject image of each color, that is, an endoscope image, formed on the light receiving surface of the CCD image sensor into an analog pixel signal for one frame, and the analog pixel signal for one frame of each color is Lighting time for each color (33 /
6ms) and the next light-shielding time (33 / 6ms)
4 are sequentially read. The reading of the analog pixel signal from the image sensor 14 is performed by the CCD driver 54 provided on the scope side.
The analog pixel signals for the frame are sent to the image signal processing circuit 56 in the image signal processing unit 12, where they are appropriately processed and then output as color video signals from the image signal processing circuit 56 to the TV monitor device 58. The endoscope image is reproduced by the TV monitor device 58 as a color image.

Referring to FIG. 9, the image signal processing circuit 56
The image signal processing circuit 56 includes a preamplifier 60 and a preprocessing circuit 62 as shown in FIG.
And an analog / digital (A / D) converter 64. In the normal light illumination mode, the analog pixel signals for one frame of each color sequentially read from the image sensor 14 are amplified by a preamplifier 60 at a predetermined amplification degree (gain), and then subjected to predetermined image processing by a preprocessing circuit 62. For example, an analog pixel signal for one frame of each color that has undergone filtering processing, white balance correction processing, gamma correction processing, contour emphasis processing, clamping processing, and the like and has undergone predetermined image processing is processed by the A / D converter 64 for one frame. Is converted to a digital pixel signal. Note that the preamplifier 60 is configured as a voltage control amplifier (VCA), and the amplification degree is variable.

Further, the image signal processing circuit 56 is provided with frame memories 66R, 66G and 66B. Once written and stored. That is, the red digital pixel signal for one frame is written to the frame memory 66R, the green digital pixel signal for one frame is written to the frame 66G, and the blue digital pixel signal for one frame is written to the frame memory 66B. When A
The digital pixel signals for one frame of each color sequentially output from the / D converter 64 are stored in a corresponding frame memory (66R, 6R).
6G, 66B). On the other hand, digital image signals of three primary colors, that is, a red digital image signal, a green digital image signal, and a blue digital image signal are simultaneously read from the frame memories 66R, 66G, and 66B,
At this time, various synchronizing signals such as a horizontal synchronizing signal and a vertical synchronizing signal are added. In short, 1
The digital image signals of the three primary colors for a frame are output from the frame memories 66R, 66G, and 66B as color (three primary colors) digital video signals for one frame (that is, component video signals).

Further, the image signal processing circuit 56 includes digital / analog (D / A) converters 68R, 68G and 68.
B, and post-processing circuits 70R, 70G, and 70B are provided. The three primary color video signals read from the frame memories 66R, 66G, and 66B, that is, the red digital video signal, the green digital video signal, and the blue digital video signal are The signals are converted into red analog video signals, green analog video signals, and blue analog video signals by the D / A converters 68R, 68G, and 68B, respectively, and then input to the post-processing circuits 70R, 70G, and 70B. In each of the post-processing circuits (70R, 70G, 70B), the analog video signal of the corresponding color undergoes predetermined image processing, for example, filtering processing, color balance processing, gamma correction processing, contour emphasis processing, and the like, and then the component video signal ( (R, G, B) to the TV monitor device 58, where the endoscope image is reproduced as a color image.

When the ultraviolet illumination mode is selected, the rotary primary color filter / shutter 44 functions as a rotary shutter.
The rotation frequency of 4 is the same as in the normal light illumination mode. Therefore, as described above, when the color filter / shutter is rotated at a rotation frequency of 30 Hz (NTSC system), ultraviolet rays are emitted from the distal end face of the light guide cable 18 by approximately 33/6.
The object is sequentially emitted at time intervals of ms, and the subject is sequentially illuminated with ultraviolet light at the time intervals. Thus, the subject is sequentially formed as an endoscopic fluorescent image on the light receiving surface of the CCD image sensor of the image sensor 14 by the objective lens system 16. The image sensor 14 photoelectrically converts the fluorescent endoscope image formed on the light receiving surface into a single-color (ultraviolet) analog pixel signal for one frame, and the single-color analog pixel signal for one frame is used for the illumination time (33 / 6ms) and the next light-shielding time (3
3/6 ms) from the image sensor 14.

It should be noted that the image sensor 14
Is also read out by the CCD driver 54 in the same manner as in the case of reading out the three primary color analog pixel signals described above.
This means that the single-color analog pixel signals for one frame sequentially read from the image sensor 14 are processed in the same manner as the analog pixel signals for one frame of each color of the three primary color analog pixel signals described above. To elaborate,
In the ultraviolet illumination mode, the color filter and shutter 4
3 frames of single color (ultraviolet light) equivalent to 1 frame of color (three primary colors) analog video signal for each rotation of 4
An analog video signal is obtained, and these three-frame single-color analog pixel signals are converted into three-frame single-color digital pixel signals by the A / D converter 64, and then distributed and stored in the frame memories 66R, 66G, and 66B. As a result, in the ultraviolet illumination mode, the frame memories 66R, 66G, and 66B output the three primary color video signals, namely, the red, green, and blue video signals corresponding to the three monochromatic (UV) signals. ) A video signal is obtained. In the ultraviolet illumination mode, only one of the three monochromatic video signals is used to reproduce a monochromatic endoscope image, that is, a fluorescent endoscopic image.

In short, by using the rotary primary color filter and shutter 44 as shown in FIG. 6, the image signal processing circuit 56 designed to generate the three primary color video signals in the normal light illumination mode can be used for the ultraviolet illumination. Can be used as it is for the creation of a monochromatic analog video signal. In other words, the image signal processing circuit 56 is commonly used for generating the three primary color video signals by the normal light illumination and the single color video signal by the ultraviolet illumination. No image signal processing circuit is required.

However, the image sensor 14 has high sensitivity to the band of visible light (three primary color lights), but the sensitivity is low to ultraviolet light. (Amplification degree) is set higher in the ultraviolet light illumination mode than in the normal light illumination mode, and the noise level of the amplified single-color (ultraviolet) analog pixel signal is higher than the noise level of the analog video signal of the three primary colors. The noise removal band setting by the filtering process in the preprocessing circuit 62 is also set higher in the ultraviolet light illumination mode than in the normal light illumination mode. Further, since the sensitivity of the image sensor 14 is different between visible light and ultraviolet light,
The clamping process in the pre-processing circuit 62, that is, the setting process for determining the pedestal level of the analog pixel signal is different between the normal light illumination mode and the ultraviolet illumination mode.

As shown in FIG. 1, a system controller 72 is provided in the image signal processing unit 12, and the system controller 72 is composed of, for example, a microcomputer. That is, the system controller 72 includes a central processing unit (CPU), a program for executing various routines, a read-only memory (ROM) for storing constants and the like, and a writable / readable memory (ROM) for temporarily storing data and the like. RAM) and an input / output interface (I / O), and controls the overall operation of the electronic endoscope. For example, the operations related to the present invention include the above-described contact switches (36 ₁ , 36 ₂ : 50 ₁ , 5
0 ₂ ) is connected to the system controller 72, whereby the rotational drive of the electric motor 34 d of the moving mechanism 34 of the mirror 32 and the electric motor 48 d of the moving mechanism 48 of the rotary primary color filter 44 is controlled, and the preamplifier (VCA) The setting of the amplification degree of 60), the setting of the noise removal band and the setting of the clamp processing in the preprocessing circuit 62 are also performed under the control of the system controller 72.

As shown in FIG. 1, the image signal processing unit 12 is also provided with a timing generator 74, and this timing generator 74 is operated under the control of the system controller 72. Various clock pulses are output from the timing generator 74 for reading analog pixel signals from the image sensor 14 and for processing image signals in the image signal processing circuit 56. The timing generator 74 has a built-in crystal oscillator for generating a basic clock pulse, and various clock pulses can be obtained by dividing the frequency of the basic clock pulse.

Regarding the reading of the analog pixel signal from the image sensor 14, the timing generator 74
This is performed according to a read clock pulse output to the CD driver 54. In order to properly read out such analog pixel signals, that is, transfer analog pixel signals from the CCD image sensor of the image sensor 14, it is necessary to output a read clock pulse output from the timing generator 74 to the CCD driver 54. The timing must be accurately synchronized with the rotational frequency of the rotary primary color filter / shutter 44. In other words, the electric motor 46 of the color filter and shutter 44 is driven to rotate in accordance with the drive pulse output from the drive circuit 76. The output timing of this drive pulse is determined by the read clock output from the timing generator 74 to the CCD driver 54. It is necessary to synchronize with the output timing of the pulse. Therefore, the output timing of the drive pulse from the drive circuit 76 is also controlled according to the clock pulse output from the timing generator 74.

Since the rotation of the electric motor 46 is accompanied by an unavoidable rotation error, the phase of the actual rotation frequency of the rotary primary color filter and shutter 44 always coincides with the phase of the drive pulse to the electric motor 46. Thus, it is necessary to eliminate the accumulation of the rotation error of the electric motor 46. For this purpose, as shown in FIG. 1, a phase detection sensor 78 is arranged at a predetermined position with respect to the color filter / shutter 44, and the rotational phase of the color filter / shutter 44 is detected by the phase detection sensor 78. . In this embodiment, the phase detection sensor 78 is configured to include a light emitting element such as a light emitting diode and a light receiving element such as a photodiode. On the other hand, as shown in FIG.
Three light shielding areas 44S of the color filter and shutter 44
One of, for example, a red filter element 44R and the blue filter first detected reflection area 80 ₁ and the second detected reflection region 80 ₂ in the light shielding region 44S between the element 44B are formed, these second The first and second detected reflection areas 80 ₁
And 80 ₂ are spaced apart by a predetermined distance in a radial direction along the boundary, for example the light shielding region 44S and a red filter element 44R. Note that the first and second detected reflection area 80 ₁ and 80 _2, can be obtained by pasting a suitable metal Hakuhen example aluminum foil pieces to the color filter and the shutter 44.

When the color filter / shutter 44 is located at the first operating position, the first detected reflection area 80
₁ is detected by the phase detection sensor 78, also when the color filters and shutters 44 are placed in the second operating position, the second detected reflection region 80 ₂ is adapted to be detected by the phase detection sensor 78 ing. That is, during the rotation of the color filter / shutter 44, the phase detection sensor 7
Numeral 8 emits light from the light emitting element, and the reflection area (8)
The rotation phase of the color filter / shutter 44 is detected by receiving the reflected light from the light receiving elements 0 ₁ and 80 ₂ ) by the light receiving element. The drive circuit of the phase detection sensor 78 is built in the drive circuit 76 of the electric motor 46, and is operated under the control of the system controller 72.

In short, the color filter and shutter 44
Every time one rotation is made, a phase detection signal is output from the light receiving element of the phase detection sensor 78 to the drive circuit 76, and the drive pulse is output from the drive circuit 76 so that the phase matches the phase of the phase detection signal. Output to the electric motor 46. Thus, the phase of the actual rotation frequency of the color filter / shutter 44 always coincides with the phase of the drive pulse to the electric motor 46, whereby the rotation drive of the color filter / shutter 44 and the analog pixel signal from the image sensor 14 are performed. Are read out in synchronization with each other.

Referring to FIG. 10, there is shown a timing chart based on the phase detection signal output from light receiving element 78a in the normal light illumination mode. As is clear from the figure, a phase detection signal is output from the light receiving element 78b for each rotation of the color filter and shutter 44, and the phase of the drive pulse from the drive circuit 76 to the electric motor 46 is the phase of the phase detection signal, That is, the phase of the rotation frequency of the color filter and shutter 44 is made to match. In the timing chart of FIG. 10, the rotation frequency of the color filter / shutter 44 is set to 30 Hz as in the above-described example, and the red light illumination (R), the green light illumination (G), The period of the blue light illumination (B) is shown as a high-level period, and the low-level period therebetween is a light-shielding period (S). In each light shielding period (S), a read clock pulse is output from the timing generator 74 to the CCD driver 54, and at this time, the analog pixel signals (R, G, B) for one frame of each color are output from the image sensor 1
4 and transferred to the image signal processing circuit 56.

Referring to FIG. 11, there is shown a timing chart based on the phase detection signal output from the light receiving element 78a in the ultraviolet illumination mode. As in the timing chart of FIG. 10, even in the ultraviolet illumination mode, a phase detection signal is output from the light receiving element 78b for each rotation of the color filter and shutter 44, and the drive circuit 76 outputs the electric motor 4
6 is the phase of the phase detection signal,
That is, the phase of the rotation frequency of the color filter and shutter 44 is made to match. Ultraviolet illumination (UV) for one rotation of the color filter / shutter 44 is repeated three times, each of which is indicated as a high level period, and a low level period therebetween is defined as a light shielding period (S). Each shading period (S)
In this case, a read clock pulse is output from the timing generator 74 to the CCD driver 54, and at this time, an analog pixel signal (UV) for one frame of a single color (ultraviolet light) is read from the image sensor 14 and the image signal processing circuit 56 Is forwarded to

As described above, various clock pulses are output from the timing generator 74 to the image signal processing circuit 56 as well. That is, as shown in FIG. 9, the pre-processing circuit 62 and the A /
D converter 64, frame memory (66R, 66G, 66
B), a clock pulse of a predetermined frequency is output to each of the D / A converters (68R, 68G, 68B) and the pre-processing circuits (70R, 70G, 70B). Preprocessing circuit 6
In 2, the various image processing as described above is performed according to the clock pulse input thereto. A / D converter 6
In 4, the conversion from the analog pixel signal to the digital pixel signal is performed according to the clock pulse or sampling pulse inputted thereto. Frame memory (66R, 6
6G, 66B), and reading of the digital pixel signal therefrom is performed according to the write clock pulse and the read clock pulse from the timing generator 74. D / A converter (68R, 68
G, 68B), the conversion from the digital video signal to the analog video signal is performed according to the clock pulse input thereto. Pre-processing circuit (70R, 70G, 70
In B), the various image processings described above are performed according to the clock pulse input thereto. In short, the process from processing the analog pixel signal obtained from the image sensor 14 to outputting it as a video signal is performed by the timing generator 74 in accordance with various clock pulses synchronized with each other.

As shown in FIG. 1, the white light lamp 24 is powered by a power supply circuit 82 and the ultraviolet lamp 26 is powered by a power supply circuit 84. Each power supply circuit (82, 8
The power supply from (4) to the corresponding lamps (24, 26) is performed under the control of the system controller 72. In the present embodiment, regarding the power supply control to each lamp (24, 26),
Each of the lamps (24, 26) can be turned on and off as required, as well as turned on and off.

More specifically, generally, when the normal light illumination mode is selected, only the white light lamp 24 is turned on and the ultraviolet lamp 26 is turned off. When the ultraviolet illumination mode is selected, only the ultraviolet lamp 26 is turned on and the white light is turned on. Light lamp 2
4 is turned off. However, in a case where the normal light illumination mode and the ultraviolet light illumination mode are frequently switched, that is, in a case where the endoscope image by the ordinary light illumination and the endoscope image by the ultraviolet light illumination are repeatedly compared and observed, one of the lamps is used. It is not preferable to turn off the other lamp during lighting. This is because frequent repetition of blinking of the lamps (24, 26) shortens the life of the lamps, and the light emission state becomes unstable immediately after each lamp is switched from off to on. It is. Therefore, in the case where the normal light illumination mode and the ultraviolet illumination mode are frequently switched, it is preferable that when one of the lamps is turned on, the other lamp is turned off.

In FIG. 1, reference numeral 86 denotes a drive circuit for driving the actuator 42 of the diaphragm 40.
6 is driven under the control of the system controller 72. More specifically, the pre-processing circuit 6 of the image signal processing circuit 56
An integration circuit is provided in 2, and an analog pixel signal read from the image sensor 14 is passed through the integration circuit. In the integration circuit in the pre-processing circuit 62, the signal level value of the analog pixel signal obtained for each rotation of the color filter / shutter 44 is integrated, and the integrated value is used as the overall endoscope image reproduced by the TV monitor device 58. The luminance is output to the drive circuit 86 as a luminance evaluation signal for evaluating the luminance. The drive circuit 86 drives the actuator 42 based on the luminance evaluation signal to adjust the opening of the diaphragm 40. That is,
The aperture of the diaphragm 40 is adjusted so that the value of the luminance evaluation signal always coincides with a predetermined reference luminance value. By adjusting the aperture of the diaphragm 40, the distance of the subject from the distance to the distal end of the scope 10 is controlled. Instead, the brightness of the reproduced endoscopic image on the TV monitor device 58 can be always kept constant.

In FIG. 1, reference numeral 88 denotes a front panel mounted on the outer wall of the housing of the image signal processing unit 12, and the front panel 88 is provided with various switches and displays. In particular, the switch according to the present invention includes a power supply O of the image signal processing unit 12 itself.
An N / OFF switch 90, a lamp ON / OFF switch 92, an illumination mode changeover switch 94, and a light extinguishing / reduced light mode changeover switch 96 are exemplified.

When the power ON / OFF switch 90 is turned on, a power supply device (not shown) provided in the image signal processing unit 12 is turned on, and the image signal processing unit 12 becomes operable. Note that the power supply device is connected to a commercial power supply via a connection plug, and supplies stable power to each of the components of the image signal processing unit 12.

The lamp ON / OFF switch 92 is a common switch for the white light lamp 24 and the ultraviolet lamp 26, and when the lamp ON / OFF switch 92 is turned on,
Both lamps 24 and 26 are ready for lighting,
When the lamp ON / OFF switch 92 is turned off, lighting of both lamps 24 and 26 is prohibited. The lamp ON / OFF switch 92 is a switch for selecting whether the lamps 24 and 26 can be turned on or turned off.
The turning on and off of the UV lamp 4 and the ultraviolet lamp 26 are individually controlled in a manner described later.

The illumination mode changeover switch 94 is a switch for selecting one of the normal light illumination mode and the ultraviolet illumination mode as described above. When the image signal processing unit 12 starts up, that is, the power ON / OFF switch 90
Is turned on, the normal light illumination mode is forcibly selected. From the illumination mode changeover switch 94 to the system controller 7
2, the output level changes from a high level to a low level when the illumination mode changeover switch 94 is pressed, and the illumination mode is detected by detecting this level change. Is switched. That is, as described above, when the image signal processing unit 12 starts up, the normal light illumination mode is selected. However, when the illumination mode changeover switch 94 is subsequently pressed, the normal light illumination mode is switched to the ultraviolet illumination mode. When the illumination mode changeover switch 94 is depressed thereafter, the mode is returned from the ultraviolet light illumination mode to the normal light illumination mode, and the illumination mode changeover is performed by repeating the depression operation of the illumination changeover switch 94 in this manner. .

An extinguishing / dimming mode switch 96 selects whether to turn off or diminish a lamp used in the other illumination mode when one of the illumination modes is selected by the illumination mode switching switch 94. When the image signal processing unit 12 starts up, the light-off mode is forcibly selected. As in the case of the lighting mode switch 94, the output level from the light-off / light-down mode change-over switch 96 to the system controller 72 is normally set to a high level, but the light-off / light-down mode changeover switch 96 is pressed. Then, the output level changes from a high level to a low level. By detecting this level change, switching between the light-off mode and the light-off mode is performed.

As shown in FIG. 1, a keyboard 98 is connected to the system controller 72.
Various command signals, data, and the like necessary for the overall operation of the electronic endoscope are input to the image signal processing unit 12 via 8. In the present embodiment, the same functions as the illumination mode switch 94 and the light-off / light-off mode change-over switch 96 are assigned to specific function keys on the keyboard 98. Can also be performed by pressing a specific function key on the keyboard 98. Of course, if necessary, the illumination mode switch 9
4 and extinguishing the light-off / light-off mode changeover switch 96,
The switching of the lighting mode and the switching of the light-off / light-off mode may be performed only by a specific function key on the keyboard 98.

Referring to FIG. 12, there is shown a flowchart of an initialization routine executed by the CPU of the system controller 72. This initialization routine is executed only once when the power ON / OFF switch 90 on the front panel 88 is turned on. You.

At step 1201, the flags CF1, CF2 and WF are initialized to "0".

The flag CF1 is an illumination mode instruction flag for indicating whether the normal light illumination mode or the ultraviolet illumination mode is selected. When CF1 = 0, it indicates that the normal light illumination mode is selected. And CF1 =
When it is 1, it indicates that the ultraviolet illumination mode is selected. In short, when the image signal processing unit 12 starts up, that is, when the power ON / OFF switch 90 is turned on,
The normal light illumination mode is forcibly selected.

The flag CF2 is a light-off / light-off mode instruction flag for indicating whether the light-off mode or the light-off mode is selected. When CF2 = 0, it indicates that the light-off mode is selected. , CF2 = 1, indicates that the dimming mode is selected. in short,
When the image signal processing unit 12 is started, the light-off mode is forcibly selected.

The flag WF is used at the time of executing the illumination mode changeover switch monitoring routine shown in FIG. 14. When the illumination change is confirmed, a standby instruction for instructing to enter a standby state for a predetermined time, for example, 3 seconds. It is a flag. That is, every time the lighting is switched, the standby instruction flag W
F is rewritten from "0" to "1". Thereafter, the illumination mode changeover switch monitoring routine (FIG. 14) is in a standby state for three seconds, during which operation associated with the shift to the illumination mode changeover (for example, mirror 32 and color filter). Shutter 4
4 is performed, and in such a standby state, even if any one of the illumination mode changeover switch 94 and the corresponding function key on the keyboard 98 is pressed, the pressing operation is invalidated. In short, a waiting time of 3 seconds is set as the time required for completing the operation accompanying the switching of the illumination mode.

In step 1202, "60" is set as an initial value in the standby time counter WC. The standby time counter WC is configured as a subtraction counter, and counts the above-described standby time of 3 seconds. The illumination mode changeover switch monitoring routine (FIG. 14) is a time interruption routine repeatedly executed every 50 ms, and the initial value “60” is set as a numerical value corresponding to 3 seconds.

[0064] At step 1203, the first whether a first contact switch 50 ₁ of the contact switch 36 ₁ and the moving mechanism 48 are both on state of the moving mechanism 34, i.e., a mirror 32 and a color filter and a shutter It is determined whether or not each of the 44 is in the first operating position. When the normal light illumination mode as described above is selected, the mirror 32 and the color filter and the shutter 44 must not be placed in the first operating position respectively, if the contact switch 36 ₁ and 50 ₁ are both turned on If it is, the process proceeds to step 1204.

In step 1204, the white light lamp 24
Is turned on, and the ultraviolet lamp 26 is turned off.
Of course, the reason why the white lamp 24 is turned on is that the normal light illumination mode is forcibly set in the initial setting (CF1).
= 0) and the ultraviolet lamp 26 is turned off because the light-off mode is forcibly set in the initial setting.

In step 1205, the amplification degree of the preamplifier 60 is set to a value corresponding to the normal light illumination mode. Then, in step 1206, various image processing performed by the pre-processing circuit 62 is set to the setting corresponding to the normal light illumination mode. Is done.

[0067] On the other hand, when the contact switches 36 ₁ and 50 ₁ are both turned off at step 1203, i.e., the power ON / OFF switch 90 as one likes the state of the ultraviolet illumination mode is turned off in the previous use of the electronic endoscope The mirror 32 and the color filter / shutter 44 are
When in the operating position (second both turned on and the contact switch 50 ₂ of the second contact switch 36 ₂ and the moving mechanism 48 of the moving mechanism 34), the process proceeds from step 1203 to step 1207, where the mirror 32 first The electric motor 34d is driven so as to move from the operation position 2 to the first operation position.
At 208, the electric motor 48d is driven so as to move the color filter / shutter 44 from the second operating position toward the first operating position. It should be noted that the mirror 32 and the color filter / shutter 44 are respectively located at the first operation position in the initial setting, of course, because the normal light illumination mode is forcibly selected when the electronic endoscope is started.

Subsequently, in step 1209, a command is issued to execute the contact switch monitoring routine shown in FIG. As described later, the micro switch monitoring routine of Fig. 16 is executed, whether the respective contact switches 36 ₁ and 50 ₁ are what time on is monitored. When the first contact switch 36 ₁ of the moving mechanism 34 is turned on, i.e., when the mirror 32 that has reached the first operating position is confirmed, the electric motor 34
The drive of d is stopped. Further, the first contact switch 50 ₁ of the moving mechanism 48 is turned on, i.e., when the color filter and the shutter 44 that has reached the first operating position is confirmed, the drive is stopped in the electric motor 48d .

After the execution command of the contact switch monitoring routine (FIG. 16) is issued in step 1209, the flow advances to step 1204 to execute the above-described initialization processing, that is, the initialization processing required for the normal light illumination mode. Is done.

Referring to FIG. 13, there is shown a flowchart of a lighting / reduced light mode changeover switch monitoring routine executed by the CPU of the system controller 72. A time interrupt routine is repeatedly executed every time, and the execution is started after the execution of the initialization routine shown in FIG. 12 and after the lamp ON / OFF switch 92 is turned on.

In step 1301, it is determined every 50 ms whether or not any of the ON / OFF mode switch 96 and the corresponding function key on the keyboard 98 has been pressed. When it is confirmed that any one of the lighting / light reduction mode changeover switch 96 and the corresponding function key on the keyboard 98 has been pressed, the process proceeds from step 1301 to step 1302, where the light emission / light reduction mode instruction flag CF2 is set to "0". Is determined as "1" or "1".

If CF2 = 0 in step 1302, that is, if the light-off mode is selected, step 13
Proceeding to step 03, the lighting mode instruction flag CF2 is rewritten from "0" to "1". That is, rewriting of the light-off / light-off mode instruction flag CF2 from “0” to “1” indicates that the mode has been switched from the light-off mode to the light-off mode. On the other hand, in step 1302, CF2 = 1
In this case, that is, when the light reduction mode is selected, the process proceeds from step 1302 to step 1304, where the light-off / light reduction mode instruction flag CF2 is rewritten from "1" to "0". That is, the light-off / light-off mode instruction flag C
Rewriting of F2 from "1" to "0" indicates that the mode has been switched from the light reduction mode to the light extinguishing mode.

Referring to FIG. 14, there is shown a flowchart of an illumination mode changeover switch monitoring routine executed by the CPU of the system controller 72. This illumination mode changeover switch monitoring routine also has an appropriate time interval, for example, 50 ms.
A time interruption routine is repeatedly executed every time. The execution is started after the execution of the initialization routine shown in FIG. 12 and the lamp ON / OFF switch 92 as in the case of the light reduction mode changeover switch monitoring routine shown in FIG. After turning on.

In step 1401, the standby instruction flag W
It is determined whether F is “0” or “1”. Since WF = 0 in the initial stage (FIG. 12), step 1
Proceeding to 402, it is determined whether one of the illumination mode changeover switch 94 and the corresponding function key on the keyboard 98 has been pressed. If the pressing operation of any of the illumination mode changeover switch 94 and the corresponding function key on the keyboard 98 is not confirmed, the present routine ends once. Thereafter, this routine is repeatedly executed every 50 ms, but no progress is made unless the pressing operation of the illumination mode changeover switch 94 and the corresponding function key on the keyboard 98 is confirmed.

If it is confirmed in step 1402 that any one of the illumination mode changeover switch 94 and the corresponding function key on the keyboard 98 is pressed, step 140
Then, the process proceeds to step 3, where the standby instruction flag WF is rewritten from “0” to “1”. Then, the operation proceeds to step 1404, where it is determined whether the illumination mode instruction flag CF 1 is “0” or “1”. . When CF1 = 0, that is, when the normal light illumination mode is selected, step 1
Proceeding to 405, the illumination mode instruction flag CF1 is rewritten from "0" to "1", thereby instructing that the normal light illumination mode has been switched to the ultraviolet illumination mode. On the other hand, when CF1 = 1, that is, when the ultraviolet illumination mode is selected, the process proceeds from step 1404 to step 1406, where the illumination mode instruction flag CF is rewritten from "1" to "0". Indicates that the mode has been switched to the normal light illumination mode. In any case, the process proceeds to step 1407, in which a command is issued to execute the illumination mode switching transition routine shown in FIG.

This routine is executed again after a lapse of 50 ms, but since WF = 1 at this time (step 14).
03), the process proceeds from step 1401 to step 1408, where "1" is subtracted from the standby time counter WC (initial setting value 60). Next, at step 1409,
It is determined whether or not the subtraction value of the standby time counter WC has reached “0”. If WC> 0, this routine ends once. Thereafter, this routine is executed every elapse of 50 ms, but at step 1409, the standby time counter WC
No progress is made until the subtraction value of reaches “0”.
In short, this routine enters a standby state (WF = 1) during execution of the illumination mode switching transition routine of FIG. 15, and the operation of the illumination mode switching transition is completed during the standby state. Of course, during such a transition to the illumination mode switching, the illumination mode switching switch 94 and the keyboard 98 corresponding thereto are switched.
Even if any of the above function keys is pressed, the pressing operation is invalidated.

In step 1409, the standby time counter WC
When the subtraction value of “.” Reaches “0”, that is, when three seconds have elapsed after entering the standby state, the process proceeds from step 1409 to step 1410, where the standby instruction flag WF is returned from “1” to “0”. Then, in step 1411, an initial setting value “60” is set in the standby time counter WC,
This routine ends once. Thereafter, this routine is executed every 50 ms, and the pressing operation of any one of the function keys on the keyboard 98 corresponding to the illumination mode changeover switch 94 and the corresponding illumination mode changeover switch 94 is monitored. Such rewriting of the illumination mode instruction flag CF1 is performed.

Referring to FIG. 15, there is shown a flowchart of an illumination mode switching transition routine executed by the CPU of the system controller 72. It is executed every time one of the illumination mode changeover switch 94 and the corresponding function key on the keyboard 98 is pressed.

At step 1501, the lighting mode instruction flag CF1 is determined, and thereby the switching of the lighting mode is determined. When CF1 = 1, this means switching from the normal light illumination mode to the ultraviolet illumination mode, and then proceeds to step 1502, where the mirror 32 is moved from the first operating position toward the second operating position. In step 1503, the electric motor 48d is driven so as to move the color filter and shutter 44 from the first operation position toward the second operation position. Subsequently, in step 1504, a command is issued to execute the contact switch monitoring routine shown in FIG.

[0080] As described later, the micro switch monitoring routine of Fig. 16 is executed, or each of the contact switches 36 ₂ and 50 ₂ is what time on is monitored. When the second contact switch 36 ₂ is turned on the moving mechanism 34, i.e., the mirror 32 that has reached the second operating position is confirmed, the driving of the electric motor 34d is stopped. Further, when the second contact switch 50 ₂ is turned on the moving mechanism 48, that is, the color filter and the shutter 44 that has reached the second operating position is confirmed, the drive is stopped in the electric motor 48d .

After the execution command of the contact switch monitoring routine shown in FIG. 16 is issued in step 1504, the process proceeds from step 1504 to step 1505, where the ultraviolet lamp 26 is turned on, and then the process proceeds to step 1506, where the light is turned off / dimmed. It is determined whether the mode instruction flag CF2 is "0" or "1". CF2 =
When the value is 0, that is, when the extinguishing mode is selected, the process proceeds to step 1507, where the white light lamp 24 is extinguished. On the other hand, when CF2 = 1 in step 1506, that is, when the dimming mode is selected, the process proceeds to step 1508, where the white light lamp 24 is dimmed.

In any case, after the white light lamp 24 is turned off or turned off, the process proceeds to step 1509, where the amplification degree of the preamplifier 60 is set to a value corresponding to the ultraviolet illumination mode. Circuit 62
Are set according to the ultraviolet illumination mode.

When CF1 = 0 in step 1501, this means switching from the ultraviolet illumination mode to the normal light illumination mode, and then proceeds from step 1501 to step 1511 where the mirror 32 is moved from the second operating position. The electric motor 34d is driven to move toward the first operating position, and then at step 1512, the electric motor is moved so as to move the color filter and shutter 44 from the second operating position toward the first operating position. 4
8d is driven. Subsequently, in step 1513, a command is issued to execute the contact switch monitoring routine shown in FIG.

[0084] As described later, the micro switch monitoring routine of Fig. 16 is executed, or each of the contact switches 36 ₁ and 50 ₁ are what time on is monitored. When the first contact switch 36 ₁ of the moving mechanism 34 is turned on, i.e., when the mirror 32 that has reached the first operating position is confirmed, the driving of the electric motor 34d is stopped. Further, the first contact switch 50 ₁ of the moving mechanism 48 is turned on, i.e., when the color filter and the shutter 44 that has reached the first operating position is confirmed, the drive is stopped in the electric motor 48d .

After the execution command of the contact switch monitoring routine shown in FIG. 16 is issued in step 1513, the process proceeds from step 1513 to step 1514, where the white light lamp 24 is turned on, and then the process proceeds to step 1515, where it is turned off / reduced. It is determined whether the light mode instruction flag CF2 is "0" or "1". CF2 =
When it is 0, that is, when the extinguishing mode is selected, the process proceeds to step 1516, where the ultraviolet lamp 26 is extinguished. On the other hand, when CF2 = 1 in step 1515, that is, when the dimming mode is selected, the process proceeds to step 1517, where the ultraviolet lamp 26 is dimmed.

In any case, after the ultraviolet lamp 26 is turned off or turned off, the process proceeds to step 1518, where the amplification degree of the preamplifier 60 is set to a value corresponding to the normal light illumination mode. Circuit 62
Are set according to the normal light illumination mode.

Referring to FIG. 16, there is shown a flowchart of a contact switch monitoring routine executed by the CPU of the system controller 72. As described above, the contact switch monitoring routine is executed in step 1209 of the initialization routine of FIG. It is executed when the execution command is issued and when the execution command is issued in steps 1504 and 1513 of the illumination mode switching transition routine of FIG.

At step 1601, the lighting mode instruction flag CF1 is determined, whereby the switching of the lighting mode is determined. When CF1 = 0, which means switching from ultraviolet illumination mode to the normal illumination mode, this time, the program proceeds to step 1602, where the first micro switch 36 ₁ is whether or not turned on in the moving mechanism 34 is Will be determined. If it is the micro-switch 36 ₁ is off, skip to step 1604, where the moving mechanism 4
8 first micro switch 50 ₁ is whether it is on is determined. If it is the micro-switch 50 ₁ is off, skip to step 1606, where whether the micro switch 36 ₁ and 50 ₁ are both turned on is determined. When the micro switch 36 ₁ and 50 ₁ are not both turned on, the flow returns to step 1602.

At step 1602, the microswitch 36
_When it is confirmed that ₁ is ON, that is, when it is confirmed that the mirror 32 has reached the first operating position from the second operating position, the process proceeds to step 1603, where the electric motor 34d
Is stopped. Further, the on of the micro switch 50 ₁ is confirmed in step 1604, i.e., when the color filter and the shutter 44 reaches the first actuating position from the second operating position is confirmed, step 1605
The driving of the electric motor 48d is stopped there.
In step 1606, the microswitches 36 ₁ and 50 ₁
When it is confirmed that both have been turned on, this routine ends.

When CF1 = 1 in step 1601, this means switching from the normal light illumination mode to the ultraviolet illumination mode. At this time, the process proceeds from step 1601 to step 1607, where the second micro switch of the moving mechanism 34 is set. 36 ₂ whether it is on is determined. If it is the micro-switch 36 ₂ is turned off, step 16
09 skips, where the second micro switch 50 ₂ is whether it is on the moving mechanism 48 is determined. If If the micro switch 50 ₂ is turned off, step 1
Skips to 611, where whether or not the micro-switch 36 ₂ and 50 ₂ are both turned on is determined. When the micro switch 36 ₂ and 50 ₂ are not both turned on, the flow returns to step 1607.

At step 1607, the microswitch 36
_When it is confirmed that the mirror ₂ has been turned on, that is, when it is confirmed that the mirror 32 has reached the second operating position from the first operating position, the process proceeds to step 1608, where the electric motor 34d
Is stopped. Further, the on of the micro switch 50 ₂ is confirmed in step 1609, i.e., the color filter and the shutter 44 that has reached the second operating position is confirmed from a first operating position, step 1610
The driving of the electric motor 48d is stopped there.
Microswitch 36 in Step 1611 ₂ and 50 ₂
When it is confirmed that both have been turned on, this routine ends.

The routine consisting of steps 1602 to 1606 and the routine consisting of steps 1607 to 1611 are repeatedly executed at appropriate time intervals, for example, every 50 ms.

Referring to FIG. 17, there is shown a modified embodiment of the rotary primary color filter / shutter 44, the rotary primary color filter / shutter of this modified embodiment being indicated generally by the reference numeral 44 '. In FIG. 17, the same reference numerals are used for components common to the color filter and shutter 44 of FIG. In the modified color filter / shutter 44 ', the red filter element 44
Only the light-shielding region 44S between R and the blue filter element 44B is projected outward in the radial direction in a sector shape, and a peripheral region excluding the sector-shaped projection (region indicated by a two-dot chain line).
Is an open area, that is, an exposure area 44E '.

When the modified color filter / shutter 44 'is used in place of the color filter / shutter 44, when the normal light illumination mode is selected (first operating position), the modified color filter / shutter 44' is turned off as shown in FIG. And functions as a three-primary-color filter in the same manner as the color filter and shutter 44 shown in FIG. On the other hand, when the ultraviolet illumination mode is selected (second
As in the case of the color filter and shutter 44 in FIG. 6, the modified color filter and shutter 44 'also functions as a rotary shutter, but the exposure time during which the image sensor 14 is exposed during one rotation is shown in FIG. 6 is much longer than the color filter and shutter 44 of FIG.

Referring to FIG. 18, there is shown a timing chart in the ultraviolet illumination mode when the modified color filter and shutter 44 'is used. As is clear from the comparison between the timing chart and the timing chart shown in FIG. 11, the ultraviolet illumination period (UV) indicated as the high level period is five times as long as the timing chart of FIG. A single-color (ultraviolet) analog pixel signal for one frame is read out from the image sensor 14 exposed during the extended ultraviolet illumination period over a light-shielding period (S) indicated as a low-level period. Therefore, when the modified color filter / shutter 44 'is used, the output of the read clock pulse from the timing generator 74 to the CCD driver 54 in the ultraviolet illumination mode is as shown in the timing charts of FIGS. It is necessary to perform in a different manner from the above. That is, as is clear from the timing chart of FIG. 18, during one rotation of the deformed color filter and shutter 44 ', a clock pulse read from the timing generator 74 to the CCD driver 54 for a light shielding period (S) corresponding to 33/6 ms. Must be output.

In short, when the modified color filter and shutter 44 'as shown in FIG. 17 is used, the read clock pulse is output from the timing generator 74 to the CCD driver 54 as shown in FIG. It must be output at the timing, and in the ultraviolet illumination mode, the timing generator 7
4 to the CCD driver 54, the read clock pulse must be output at the output timing as shown in FIG. In other words, every time the illumination mode is switched, the output timing of the read clock pulse from the timing generator 74 to the CCD driver 54 must be changed.

It should be noted here that when the ultraviolet illumination mode is selected using the modified color filter and shutter 44 'shown in FIG. 17, various processing timings in the image signal processing circuit 56 are changed. It is not necessary.

More specifically, in the example of the timing chart shown in FIG. 18, the read timing at which a single-color (ultraviolet) analog pixel signal for one frame is read from the image sensor 14 is a blue analog pixel in the normal light illumination mode. Since it matches the read timing when the signal is read,
A single-color analog pixel signal for one frame read from the image sensor 14 is converted into a digital pixel signal by a digital pixel A / D converter 64, and the digital pixel signal for one frame is stored in a frame memory 66B. Is done. Therefore, when the ultraviolet illumination mode is selected, only the video signal output from the preprocessing circuit 70B is sent to the TV monitor device 58, and a monochromatic endoscope image is reproduced by the TV monitor device 58 based on the video signal.

In the case described above, the operation of writing the digital pixel signal into the other two frame memories 66R and 66G is performed at a predetermined timing. Therefore, the video signals are output from the preprocessing circuits 70R and 70G, respectively. However, the digital pixel signals written to the frame memories 66R and 66G are insubstantial, and the processing circuits 70R and 70G merely output apparent video signals. .
In short, the various processes in the image signal processing circuit 56 are apparently performed at a predetermined timing in the same manner as in the normal light illumination mode. Thus, even if the ultraviolet illumination mode is selected using the modified color filter and shutter 44 'shown in FIG.
It is possible to reproduce the monochromatic endoscope image by the ultraviolet illumination with the TV monitor device 58 without changing the various processing timings in Step 6.

In the case where the modified color filter and shutter 44 'shown in FIG. 17 is used, it is necessary to slightly change the initial setting routine shown in FIG. 12. Referring to FIG. A modification example is shown.

As shown in FIG. 19, step 1900 is provided at an appropriate place, for example, immediately before step 1204. In short, in the initial setting routine, the normal light illumination mode is forcibly selected.
The output timing of the read clock pulse output from the timing generator 74 to the CCD driver 54 is set so as to follow the normal light illumination mode. That is, the output timing of the read clock pulse is as shown in FIG.

Similarly, when the modified color filter / shutter 44 'shown in FIG. 17 is used, the illumination mode switching routine shown in FIG. 15 also needs to be slightly changed. A modified example of the illumination mode switching transition routine is shown.

As shown in FIG. 20, step 2000 is provided at an appropriate location, for example, immediately before step 1509, and step 2001 is also provided at an appropriate location, for example, immediately before step 1518. Step 20 when switching from the normal light illumination mode to the ultraviolet illumination mode.
At 00, the output timing of the read clock pulse output from the timing generator 74 to the CCD driver 54 is set so as to follow the ultraviolet illumination mode. That is, the output timing of the read clock pulse is as shown in FIG. On the other hand, when the mode is switched from the ultraviolet illumination mode to the normal light illumination mode, step 20 is executed.
In 01, the output timing of the read clock pulse output from the timing generator 74 to the CCD driver 54 is set so as to follow the normal light illumination mode. That is, the output timing of the read clock pulse is as shown in FIG.

Needless to say, an advantage of using the modified color filter and shutter 44 'as shown in FIG. 17 is that a sufficient exposure time is given to the image sensor 14. As described above, the imaging sensor 1
Since the CCD image pickup device used in No. 4 has low sensitivity to ultraviolet rays, an endoscope image with sufficient brightness can be obtained by lengthening the exposure time.

When the illumination mode is switched, the mirror 3
2 and the movement of the color filter and shutter (44, 44 '), the proper illumination is not performed, so that the reproduced endoscope image of the TV monitor device 58 is extremely disturbed. In order to avoid the reproduction of such a disturbed image, it is preferable to forcibly close the aperture 40 completely. For this purpose, for example, a step of forcibly and fully closing the diaphragm 40 is provided immediately before step 1601 of the contact switch monitoring routine of FIG.
Immediately after 11 a step can be provided to return the aperture 40 to normal control.

In the embodiment of the electronic endoscope according to the present invention described above, the ultraviolet lamp 2 is used as the special wavelength light source.
Although 6 is used, an infrared lamp, for example, may be used as another special wavelength light source.

[0107]

As is apparent from the above description, according to the electronic endoscope according to the present invention, the normal light illumination and the special wavelength light illumination can be performed by the common light guide cable, that is, one unit. The endoscope image obtained by the normal light illumination and the special wavelength light illumination can be obtained by the electronic endoscope described above, so that diagnosis and diagnosis based on the normal light illumination and the special wavelength illumination can be performed at low cost. Also, when compared with the case of an electronic endoscope configured to perform special wavelength light illumination by inserting the light guide cable for special wavelength light illumination into the treatment tool insertion passage of the scope,
The electronic endoscope according to the present invention also has an advantage that the user can concentrate on the operation of the scope at the time of illuminating the special wavelength light.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing an embodiment of an electronic endoscope according to the present invention.

FIG. 2 is a schematic diagram showing a relationship between a mirror and a rotary primary color filter and shutter when a normal light illumination mode is selected in the illumination device shown in FIG. 1;

FIG. 3 is a schematic diagram showing a relationship between a mirror and a rotary primary color filter / shutter when an ultraviolet illumination mode is selected in the illumination device shown in FIG. 1;

FIG. 4 is an elevation view of the mirror moving mechanism shown in FIGS. 2 and 3;

FIG. 5 is a sectional view taken along the line VV of FIG. 4;

FIG. 6 is a front view of the rotary primary color filter / shutter shown in FIGS. 2 and 3;

FIG. 7 is an elevational view of the moving mechanism of the rotary primary color filter and shutter shown in FIGS. 2 and 3;

FIG. 8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a detailed block diagram of the image signal processing circuit shown in FIG. 1;

FIG. 10 is a timing chart when a normal light illumination mode is selected in the electronic endoscope shown in FIG. 1;

FIG. 11 is a timing chart when an ultraviolet illumination mode is selected in the electronic endoscope shown in FIG. 1;

FIG. 12 is a flowchart of an initialization setting routine executed by a system controller in the image signal processing unit of the electronic endoscope shown in FIG.

FIG. 13 is a flowchart of a lighting / reducing mode changeover switch monitoring routine executed by a system controller in the image signal processing unit of the electronic endoscope shown in FIG. 1;

FIG. 14 is a flowchart of an illumination mode changeover switch monitoring routine executed by a system controller in the image signal processing unit of the electronic endoscope shown in FIG. 1;

FIG. 15 is a flowchart of an illumination mode switching transition routine executed by a system controller in the image signal processing unit of the electronic endoscope shown in FIG. 1;

FIG. 16 is a flowchart of a contact switch monitoring routine executed by a system controller in the image signal processing unit of the electronic endoscope shown in FIG. 1;

FIG. 17 is a front view showing a modification of the rotary primary color filter and shutter shown in FIG. 6;

FIG. 18 is a timing chart when an ultraviolet illumination mode is selected using the rotary primary color filter and shutter shown in FIG. 17;

FIG. 19 is a part of a flowchart showing a part of the initialization setting routine of FIG. 8 that needs to be changed when the rotary primary color filter and shutter shown in FIG. 17 is used;

20 is a part of a flowchart showing a part to be changed in an illumination mode switching transition routine of FIG. 15 when the rotary primary color filter and shutter shown in FIG. 17 are used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Scope 12 Image signal processing unit 14 Image sensor 18 Light guide cable 24 White light lamp 26 Ultraviolet lamp 32 Mirror 34 Moving mechanism 44 Rotary three primary color filter and shutter 48 Moving mechanism 56 Image signal processing circuit 58 TV monitor 72 System controller 74 Timing generator 90 Power ON / OFF switch 92 Lamp ON / OFF switch 94 Illumination mode switch 96 and OFF / Dark mode switch

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takayuki Enomoto 2-36-9 Maeno-cho, Itabashi-ku, Tokyo Asahi Gaku Kogyo Co., Ltd. F-term (reference) 2H040 BA09 CA02 CA09 CA11 CA12 CA23 DA03 DA15 DA51 GA02 GA05 GA06 4C061 AA00 BB02 CC06 DD00 GG01 HH51 LL02 MM01 MM03 NN01 NN05 NN10 QQ02 QQ03 QQ04 QQ07 QQ09 RR02 RR04 RR15 RR17 RR22 RR26 SS05 SS09 SS11 SS17 SS18 WW17 5C054 CA03 CA04 CB00 CC03 CC03 CC

Claims (6)

[Claims] 1. A scope comprising: a scope; an image sensor provided at a distal end of the scope; and an image signal processing unit connected to a proximal end of the scope. An electronic endoscope that outputs a video signal after being appropriately processed by the image signal processing unit, and is further inserted through the scope to guide illumination light for illuminating the front of a distal end of the scope. A light guide cable and a lighting device provided in the image signal processing unit, wherein a proximal end of the light guide cable is optically connected to the lighting device when the scope is connected to the image signal processing unit. In the electronic endoscope, the illumination device is a normal light source, a special wavelength light source, a normal light from the normal light source and a special wavelength light from the special wavelength light source. Electronic endoscope characterized in that it comprises a light source switching means for directing the proximal end face of the or selectively the light guide cable one. 2. The electronic endoscope according to claim 1, wherein
The light source switching means comprises a light deflecting means, and a moving mechanism for moving the light deflecting means between a first operating position and a second operating position, wherein the light deflecting means is in its first operating position. The normal light from the normal light source is guided to a proximal end face of the light guide cable, and the light deflecting means intercepts the normal light from the normal light source at the second operation position and the special wavelength light from the special wavelength light source. Endoscope for guiding the light guide cable to a proximal end face of the light guide cable. 3. The electronic endoscope according to claim 1, wherein a rotary primary color filter / shutter is provided between a proximal end face of the light guide cable and the light source device.
A moving mechanism for moving the rotary three primary color filter / shutter between a first operating position and a second operating position, wherein normal light from the normal light source is transmitted to a proximal end face of the light guide cable. When guided, the rotary tri-color filter and shutter is placed in the first operating position, and at this time the proximal end of the light guide cable receives normal light from the normal light source as the rotary tri-color filter. When the special wavelength light from the special wavelength light source is guided to the proximal end face of the light guide cable through the shutter at predetermined time intervals as three primary color lights, the rotating three primary color filter / shutter is used for the second primary color light. In the working position, the special wavelength light from the special wavelength light source is incident on the proximal end face of the light guide cable at a predetermined time interval. Electronic endoscope according to claim Rukoto. 4. The electronic endoscope according to claim 3, wherein
The rotary primary color filter / shutter is composed of a disk element, and the primary color filter and three light shielding areas are alternately arranged at predetermined intervals along the circumferential direction of the disk element. An electronic endoscope, wherein at least one of the regions projects radially outward, and the projection functions as a rotary shutter. 5. The electronic endoscope according to claim 3, wherein
Only one of the three light-shielding regions of the rotary primary color filter / shutter protrudes radially outward,
The overhanging portion functions as a rotary shutter, and reading of three primary color pixel signals read from the image sensor during the normal light illumination and reading of a single color pixel signal read from the image sensor during the special wavelength light illumination are performed. An electronic endoscope, which is performed at different timings. 6. A rotary primary color filter and shutter interposed between the proximal end face of the light guide cable and the light source device in the electronic endoscope according to claim 1 or 2, wherein the disc is a disc. And three color filters and three light-shielding regions alternately arranged at predetermined intervals along the circumferential direction of the disk element, and at least one of the light-shielding regions projects radially outward. A rotary primary color filter, wherein the overhanging portion functions as a rotary shutter.