JP2002325727A - Electronic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a color image by using a light source for white illumination in an electronic endoscope using a monochromatic imaging device. SOLUTION: A disk-like color separation filter 27 and a motor 28 are positioned within the connector part 20 of the electronic endoscope 10. RGB color filters are provided at an opening formed along the periphery of the color separation filter. The filter 27 is rotated by a prescribed period by the motor 28 with the center of a disk as an axis. Light is guided to the filter 27 through a light guide from a lamp 46 within a processor 40 and separated to be RGB lights through the opening where the respective color filters are provided. The separated RGB lights are emitted from an ejection end 15a through a light guide 15. The images of RGB are detected one by one by a monochromatic CCD 14 corresponding to the emission of the RGB lights and stored temporarily in field memories 22r, 22g and 22b. The images in the respective field memories are synchronized and outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field sequential type electronic endoscope.

[0002]

2. Description of the Related Art In recent years, a simultaneous type electronic endoscope using an on-chip color CCD has been widely used with an increase in the number of pixels of a CCD. Particularly, it is widely used in a field where the diameter of the insertion portion is not so required to be reduced, and accordingly, a light source device for white illumination is widely used. However, in a high pixel on-chip color CCD, the number of pixels is increasing with an increase in pixel density, and the size of the entire CCD is not so small. Further, since a large number of drive signals are required to drive the current on-chip color CCD, a large number of signal transmission cables are required, and the insertion portion of the electronic endoscope using the on-chip color CCD is thin. It is difficult to reduce the diameter. Therefore, there is a limit in using an on-chip color CCD with a large number of pixels for an electronic endoscope that requires a thin insertion portion such as a respiratory system, a urinary system, and an otolaryngology system.

On the other hand, as a high-pixel-size and small-sized image sensor, a monochrome image sensor has been conventionally used. In order to shoot a color image with an electronic endoscope using a monochrome image sensor, a frame sequential method is usually used. In the field sequential method, R
(Red), G (green), B (blue), etc., are illuminated as illumination light, and time-series RGB images are captured under RGB illumination.
Are obtained as a set of monochrome images. Therefore, in the field sequential method, a light source device that irradiates RGB illumination light sequentially in a time series is required.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic endoscope using a monochrome type image pickup device which can also be used as a light source for white illumination.

[0005]

An electronic endoscope according to the present invention comprises:
An electronic endoscope detachably connected to a processor, comprising: a monochrome image sensor; and color separation means for separating / extracting white light in a time series at a predetermined cycle for each color component of a three-color system. A first light transmission means for transmitting light from a light source provided to the light source device to the color separation means, and a first light transmission means for transmitting each color in a predetermined cycle in the color separation means in time series. A second light transmission unit that transmits light from a light source separated for each component to the distal end of the electronic endoscope and irradiates the light as illumination light for each color component; It is characterized in that it comprises a plane-sequential image pickup means for picking up a monochrome image for each color component in accordance with a predetermined cycle with light, and generating a video signal of a color image synchronized based on the monochrome image.

The color separation means includes, for example, a color separation filter in which three openings are provided at predetermined intervals along the circumference of a rotating disk, and each opening is provided with a color filter for separating a color component, and a center of the disk. A rotation driving device for rotating the color separation filter at a predetermined period around the axis, wherein light from the first optical transmission means sequentially passes through the color filter in time series with the rotation of the color separation filter. As a result, light of each color component is separated and extracted. Each color component of the three-color system is, for example, red, green, and blue.

Further, an electronic endoscope system according to the present invention includes the above-mentioned electronic endoscope.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram schematically showing a circuit configuration of an electronic endoscope system according to one embodiment of the present invention.

The electronic endoscope system according to the present embodiment includes an electronic endoscope 10, a video signal processing device (built-in light source) 40,
The outline of the monitor 50 is shown. The electronic endoscope provided with the image pickup device is detachably connected to a video signal processing device (hereinafter referred to as a processor) 40, and the TV monitor 50 is connected to the processor 40 via a video signal cable. In this embodiment, only the TV monitor 50 is shown as a peripheral device, but a peripheral device such as a video printer, a VCR, and a computer may be connected at the same time.

The electronic endoscope 10 is connected to an elongated and flexible insertion portion 11, an operation portion 12 for operating the electronic endoscope, a flexible connecting portion 13, and a processor 40. And a connector section 20 for performing the operation. At the tip of the insertion portion 11, a monochrome multi-pixel C is used as a high-resolution image sensor.
An emission end 15a of the CD 14 and the light guide 15 (second optical transmission means) is arranged. The driving of the CCD 14 is controlled by a CCD driving pulse output from a CCD driver 24 provided in the connector section 20, and the CCD driver 24 is driven based on a clock pulse output from a timing control circuit 25.

The light guide 15 is composed of a bundle of ultra-fine optical fibers, and R (red), G (green), and B (blue) illumination light are emitted from one end, an exit end 15a, as described later. Injected sequentially in chronological order. In the CCD 14, an image is taken in accordance with the RGB illumination light emitted from the emission end 15a, and a monochrome field image corresponding to each color of RGB is detected as an analog image signal. This image signal is sent to the connector section 20 of the electronic endoscope 10 via a signal cable and is input to the pre-processing circuit 21. The pre-processing circuit 21 amplifies the image signal from the CCD 14 to an appropriate signal level, performs signal processing such as sample hold, blanking, clamping, white balance, and gamma correction, and converts the image signal into a digital image signal. You. The digital image signal is converted into a monochrome field image for each of RGB by a field memory 22.
r, 22g, and 22b and temporarily stored in order. RGB in field memories 22r, 22g, 22b
When one set of the field images is prepared, these are synchronized and output to the post-processing circuit 23. In the post-processing circuit 23, the digital image signal is converted into an analog signal, subjected to amplification, clamping, and blanking processing, and is converted into, for example, a luminance signal Y and a color signal C. The luminance signal / color signal Y / C is output to the video signal processing circuit 41 of the processor 40 via the terminal group 31a. Pre-processing circuit 2
1. The field memories 22r, 22g, 22b and the post-processing circuit 23 are controlled by a system control circuit 26 based on a pulse signal from a timing control circuit 25. The drive of the timing control circuit 25 is controlled by the system control circuit 26.

The RGB light emitted from the exit end 15a of the light guide 15 is a lamp (light source) of the processor 40.
Supplied from 46. The lamp 46 is a white light source, and is composed of, for example, a xenon or halogen lamp or a number of LEDs. After the amount of white light from the lamp 46 is adjusted by the diaphragm 45, the white light is focused on the incident end 16b of the light guide 16 (first light transmission means). Incident end 16b
Is incident on the light guide 16 and is guided into the connector section 20 along the light guide 16, and the R light, the G light, and the B light are provided by the color separation mechanism including the color separation filter 27 provided in the connector section 20. Is decomposed into

That is, the emission end 16 of the light guide 16
a and the incident end 15b of the light guide 15
a is arranged facing each other with a predetermined gap so that the optical axis extending from the optical axis a substantially coincides with the optical axis extending from the incident end 15b.
7 is inserted. The color separation filter 27 is provided with three openings at substantially equal intervals along the circumferential direction, and each opening is provided with an RGB color filter (see FIG. 3). The color separation filter 27 is driven by a motor (rotation driving device) 28 around the center of the disk, for example, from 1200 to 18
It is rotated at 00 rpm. The rotation axis is the color separation filter 27
And is provided substantially parallel to the optical axis described above. The rotation axis is arranged so that each of the RGB color filters crosses the optical axis when the disk rotates. Thereby, the white light emitted from the emission end 16a is
With the rotation of the disk, the light is sequentially incident from the incident end 15b through the RGB color filters, and is emitted from the exit end 15a of the light guide 15 as R light, G light, and B light, respectively.
In the CCD 14, in accordance with the irradiation of the RGB light,
GB monochrome images are sequentially detected. That is, CC
D14 and the drive of the motor 27 are synchronized. The rotation of the motor 28 is controlled by the motor control circuit 29 based on the clock pulse of the timing control circuit 25.

The operation unit 12 of the electronic endoscope 10 is provided with an operation button group (operation switch group) A. The operation of the operation button group A is transmitted to the system control circuit 26 via a signal line. Is done. The system control circuit 26 is connected to the system control circuit 42 of the processor 40 via the terminal group 31b. The operation button group A is used, for example, for displaying a freeze image and recording the freeze image. In addition, power is supplied to the scope power supply 30 of the electronic endoscope 10 from the power supply 43 of the processor 40 via the terminal group 31c.

The processor 30 includes a video signal processing circuit 4
1. The system generally includes a system control circuit 42, an aperture 45, a lamp 46, a lamp control circuit 47, and a front panel 44.

As described above, the light emitted from the lamp 46 is condensed on the incident end 16b of the light guide 16 via the stop 45, and is incident on each optical fiber from the incident end 16b. The light guide 16 is provided in the connector section 20 of the electronic endoscope 10. The light guide 16 is inserted into the processor 30 by connecting the connector section 20 to the processor 30, and the incident end 16 b of the light guide 16 is connected to the lamp 46. It is arranged at a position where light is collected. As a result, the light is transmitted to the distal end of the electronic endoscope 10 (the distal end of the insertion section 11) via the light guide 16, the color separation filter 27, and the light guide 15, and is emitted from the exit end 15a as RGB illumination light.
The lighting of the lamp 46 is controlled by a lamp control circuit 47, and the driving of the lamp control circuit 47 and the aperture 45 are controlled by the system control circuit 42.

The video signal processing circuit 41 includes the electronic endoscope 1
The video signal output from the 0 post-processing circuit 23 is input via the terminal group 31a, and conventionally known video signal processing is performed. The video signal subjected to the various signal processing is output to the TV monitor 50 together with a synchronization signal as a luminance signal Y and a color signal C. The video signal processing circuit 41 is controlled by a system control circuit 42. Further, a front panel 44 provided with various operation switches is connected to the system control circuit 42, so that adjustment of the RGB gain in the video signal processing circuit 41 and the like can be performed.

FIG. 2 shows an electronic endoscope 1 according to this embodiment.
FIG. 3 is a diagram schematically illustrating a configuration of a color separation mechanism provided in a connector unit of No. 0;

The connector section 20 has a substantially rectangular parallelepiped outer shape, and a wiring board 33 is provided in the center of the inside thereof, and each circuit provided in the connector section 20 shown in FIG. 1 is arranged. A connecting portion 13 connected to the operation portion 12 is provided on a left side surface of the connector portion 20 in the drawing. On the right side in the figure, a round connector 31 for making an electrical connection with the processor 40 and a cylindrical tube 16 made of metal or the like are provided.
The light guide 16 whose periphery is protected by c is provided so as to protrude vertically. The circular connector 31 includes the terminal groups 31a, 31b, 31c and the like in FIG. 1, and each terminal is connected to the wiring board 3 via a flexible printed wiring board 34, for example.
3 is connected. The signal cable 35 is a group of signal lines connected to the CCD 14 and the operation button group A provided at the distal end of the electronic endoscope 10.

The cylindrical tube 16c is fixed to a casing of the connector portion 20 by a support member 17, and lenses 16d and 16e are provided at both openings. Further, the incident end 15b of the light guide 15 is also the cylindrical tube 1
5c, the incident end 15b of the cylindrical tube 15c.
A lens 15d is provided in the opening on the side. A disc-shaped color separation filter 27 is disposed between the light guide 15 and the light guide 16, and its rotation axis Lr is
The worm gear 38 is provided substantially in parallel with the optical axes of the light guides 15 and 16, for example. In the present embodiment, the motor 28 is fixed to the casing of the connector section 20 by the support member 18 along the side surface (the right side surface in the figure) on which the round connector 31 and the cylindrical tube 16c are provided. At this time, the rotation axis of the motor 28 is the rotation axis L
It is arranged in a plane orthogonal to r. A worm 37 is provided on the rotating shaft of the motor 28 and meshes with a worm gear 38 of the color separation filter 27 to form a worm gear. Thus, the rotation of the motor 28 is transmitted to the disc-shaped color separation filter 27. The motor 28 is connected to the wiring board 33 via a cable 36. Further, the light guide 15 is guided to the distal end of the electronic endoscope 10 via the connecting portion 13.

FIG. 3 is a plan view of the color separation filter 27. The color separation filter 27 has a rotation axis Lr as shown in FIG.
, And fan-shaped openings 27R, 27G, and 27B are provided at substantially equal intervals along the circumferential direction. The openings 27R, 27G, 27B are respectively R,
It is covered with G and B color filters. Color separation filter 2
As described above, since the openings 27R, 27G, and 27B are arranged so as to cross the optical axes of the light guides 15 and 16 as the disk rotates as described above, the period of time when the openings 27R cross the optical axis is R. The light of G is emitted from the exit end 15a of the light guide 15 while the opening 27G crosses the optical axis, and the light of G is emitted while the opening 27B crosses the optical axis.

As described above, according to the present embodiment, a video signal processing apparatus for an electronic endoscope having a white light source for picking up a color image in a simultaneous mode is provided with a monochrome CCD having a small diameter. By connecting an electronic endoscope, a color image of a frame sequential method can be obtained. As a result, the video signal processing device can be used as both the frame sequential type and the simultaneous type electronic endoscope, so that it is not necessary to prepare a video signal processing device for each of the two imaging methods, and it is possible to save costs and storage space of the device. . In addition, since there is no need to prepare or operate a different video signal processing device for each imaging method, it is possible to perform examinations and treatments efficiently.

In this embodiment, RGB color filters are used, but other color filters of a color system may be used. In the present embodiment, the rotation speed of the color separation filter is set to 1200 to 1800 rpm, but the rotation speed of the color separation filter is determined by the video signal transmission method (NTSC, PAL).
The standard depends on the TV broadcasting standard and the video signal standard for a personal computer, etc.), and is not limited to the exemplified values.

In this embodiment, the motor for rotating the color separation filter is arranged so that its rotation axis is in a plane perpendicular to the rotation axis of the color separation filter. It is not limited. In addition, the size and ratio of the aperture provided in the color separation filter depend on the sensitivity characteristics of the image sensor, the driving method, and the like, and can be changed as appropriate.

[0025]

As described above, according to the present invention, it is possible to obtain an electronic endoscope using a monochrome type image pickup device that can also be used as a light source for white illumination.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically illustrating a circuit configuration of an electronic endoscope system according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a physical configuration of a color separation mechanism provided in a connector section of the electronic endoscope shown in FIG.

FIG. 3 is a plan view of a color separation filter.

[Explanation of symbols]

 14 CCD 15 Light guide 16 Light guide 21 Pre-processing circuit 22r, 22g, 22b Field memory 23 Post-processing circuit 24 CCD driver 25 Timing control circuit 27 Color separation filter 28 Motor 29 Motor control circuit 46 Lamp

Continued on the front page F term (reference) 2H040 BA09 CA04 CA09 CA10 GA02 GA05 4C061 AA07 AA11 AA12 AA13 AA15 BB02 CC06 DD00 FF07 FF46 LL02 MM01 MM03 NN01 QQ09 RR04 RR14 RR18 RR26

Claims (4)

[Claims] 1. An electronic endoscope detachably connected to a processor, comprising: a monochrome image sensor; and a white light separating / separating a white light in a time-series at a predetermined cycle for each color component of a three-color system. A color separation unit to be extracted; a first light transmission unit that transmits light from a light source provided in the light source device to the color separation unit; a color separation unit that is transmitted by the first light transmission unit. In the second, the light from the light source separated for each of the color components in a time series at the predetermined cycle is transmitted to a distal end portion of the electronic endoscope, and irradiated as illumination light for each of the color components.
And a light transmission unit, wherein the image pickup device captures a monochrome image for each color component in accordance with the predetermined cycle with the illumination light for each color component, and an image of a color image synchronized based on the monochrome image. An electronic endoscope comprising: a frame sequential imaging unit that generates a signal. 2. The electronic endoscope according to claim 1, wherein each color component of the three-color system is red, green, and blue. 3. A color separation filter, comprising: a color separation filter provided with three openings at predetermined intervals along a circumference of a rotating disk; and a color filter provided in each of the openings to separate the color component. A rotation driving device that rotates the color separation filter at a predetermined cycle around the center of the disk, wherein the light from the first optical transmission unit emits the color with the rotation of the color separation filter. 2. The electronic endoscope according to claim 1, wherein the light of each color component is separated and extracted by sequentially transmitting the filters in a time series. 4. An electronic endoscope system comprising the electronic endoscope according to claim 1.