JP2004121486A - Light source equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide light source equipment with which an image with a good S/N is obtained correspondingly to a color imaging device and an endoscope. <P>SOLUTION: This light source equipment 3 to be used by being connected with a video scope 2A incorporating a CCD (central processing unit) 17 is designated to make illumination light generated at a lamp 23 pass through one of a plurality of filters 33a, or the like, fitted to a rotatable rotation filter 32 to be fed to the end face of a connector 15 through which a light guide 12 is put. With a discrimination signal by a CCD discrimination circuit 26, a filter control circuit 36 controls inserting and removing of a filter arranged on an illumination optical path via a motor 35 to feed the video scope 2A with the illumination light of spectral characteristics optimal to that of the CCD 17 to be used actually for picking up the image of the good S/N. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a light source device having a plurality of types of optical filters.
[0002]
[Prior art]
As a conventional example, there is a light source device disclosed in JP-A-63-234938 and JP-A-5-176881.
Japanese Patent Application Laid-Open No. 63-234938 discloses an apparatus in which one signal processing device automatically adjusts the color tone corresponding to various endoscopes.
In Japanese Patent Application Laid-Open No. Hei 5-176883, an endoscope is identified, a CCD as an image pickup device built in the endoscope is identified, and a signal processing circuit corresponding to the CCD is selected. Disclose something.
[0003]
In these conventional examples, color correction according to the type of CCD is performed electrically. However, when the electrical correction is performed, noise is also lifted at the same time, so that the image sometimes has a poor S / N ratio.
In addition, the spectral intensity and light distribution according to the endoscope (scope) are not particularly corrected by a filter.
[0004]
[Patent Document 1]
JP-A-63-234938
[Patent Document 2]
JP-A-5-176881
[Problems to be solved by the invention]
As described above, in the conventional example, the color correction is performed electrically according to the type of the CCD. However, since the spectral intensity of the illumination light is not appropriate for the CCD or the like, S / S This includes drawbacks to be improved from the viewpoint of obtaining an optimal or good image with a good N.
[0007]
(Object of the invention)
The present invention has been made in view of the above points, and has as its object to provide a light source device capable of obtaining an image with a good S / N ratio corresponding to a color image sensor or an endoscope. .
[0008]
[Means for Solving the Problems]
In a light source device used with a plurality of types of color imaging means having different spectral characteristics,
A plurality of types of optical filters respectively corresponding to the plurality of types of color imaging means,
Filter insertion / removal means capable of selectively inserting / removing the plurality of types of optical filters on the optical axis of a light source lamp capable of generating illumination light,
Control means for controlling the filter insertion / removal means based on a determination result of the determination means for determining the color imaging means to be used;
The illumination light is supplied by selecting an optical filter having a spectral characteristic that is optimal or appropriate to the spectral characteristic of the color imaging unit actually used, even when used with color imaging units having different spectral characteristics. Thus, it is possible to supply illumination light capable of obtaining an image having a good S / N.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First Embodiment)
FIGS. 1 to 3 relate to a first embodiment of the present invention. FIG. 1 shows the entire configuration of an endoscope system having the first embodiment of the present invention. FIG. 3A to FIG. 3D show the filter characteristics of the first to fourth filters provided in the rotary filter.
[0010]
As shown in FIG. 1, an endoscope system 1 for performing an endoscope inspection includes a video scope (electronic endoscope) 2A and an endoscope according to the first embodiment for supplying illumination light to the video scope 2A. A mirror light source device (hereinafter simply referred to as a light source device) 3, a TV camera device (or camera control unit) 4 for performing signal processing on a color image pickup means built in the video scope 2 </ b> A, A color monitor 5 for displaying a corresponding endoscope image when a video signal is input.
[0011]
A video scope 2B shown by a two-dot chain line in FIG. 1 which incorporates color imaging means having different color imaging characteristics (spectral characteristics) from the video scope 2A is replaced by a light source device 3 and a TV camera device 4 instead of the video scope 2A. To perform endoscopy.
[0012]
In other words, the light source device 3 of the present embodiment can be used by connecting video scopes 2A and 2B incorporating a plurality of types of color imaging means having different spectral characteristics. Illumination light can be supplied.
[0013]
The video scope 2A is an elongated insertion portion 10 inserted into a body cavity or the like, an operation portion 11 provided at a rear end of the insertion portion 10 and held by an operator to perform an operation, and, for example, a rear portion of the operation portion 11 A light guide cable portion 13 extending from an end and having a light guide 12 for transmitting illumination light inserted therethrough, and a signal cable portion 14 extending from a side portion of the operation portion 12. The connectors 15 and 16 provided at the ends of the signal cable unit 14 are detachably connected to the light source device 3 and the TV camera device 4, respectively.
[0014]
The insertion section 10 is provided at a tip thereof, and has a tip section 18 in which, for example, a charge imaging element (abbreviated as CCD) 17 as a color imaging means is built in, and a bendable section provided at a rear end of the tip section 18. The bending portion 19 includes a long flexible portion 20 extending from the rear end of the bending portion 19 to the front end of the operation portion 12. The bending portion 19 is operated by operating a bending knob 21 provided on the operation portion 11. , The bending portion 19 can be bent in a desired direction.
[0015]
A light guide 12 inserted through a light guide cable portion 13 is inserted into the insertion portion 10 and the operation portion 11. The light guide 12 is provided inside the light source device 3 by connecting a connector 15 to the light source device 3. Illumination light from the lamp 23 is supplied, and the illumination light is emitted forward from an illumination window (not shown) provided at the distal end portion 18 to illuminate a subject such as an affected part.
[0016]
The illuminated subject is formed into an image at an image forming position by an objective lens (not shown) attached to an observation window provided adjacent to the illumination window, and is photoelectrically converted by the CCD 17 arranged at the image forming position.
[0017]
The CCD 17 is connected to an electrical contact of a connector 16 via a signal line inserted through the inside of the insertion section 10 and the like. By connecting the connector 16 to the TV camera device 4, a video signal processing circuit inside the TV camera device 4 is provided. The video signal processing circuit 24 converts the output signal of the CCD 17 into a video signal. This video signal is input to a color monitor, and a subject image picked up by the CCD 17 is displayed on the display surface in color as an endoscope image.
[0018]
In addition, for example, a CCD information generating unit 25 is provided inside the connector 16 so that the CCD information of the type of the CCD 17 can be determined by an electric contact portion or a ROM, and the connector 16 is connected to the TV camera device 4. As a result, the CCD information generating section 25 and the CCD discriminating circuit 26 are electrically connected, and the information from the CCD information generating section 25 can be read (determined) by the CCD discriminating circuit 26 provided inside the TV camera device 4. ing.
[0019]
The signal determined by the CCD determination circuit 26 is sent to the light source device 3 via the connection cable 27 and input to the filter control circuit 36, and the light source device 3 is connected to the CCD 17 built in the connected video scope 2A. Suitable illumination light can be supplied to the light guide 12 of the video scope 2A.
[0020]
In the light source device 3 of the present embodiment, after the illumination light generated by the lamp 23 is converted into a parallel light flux by the first lens 31 disposed on the optical path, the optical filter (hereinafter, referred to as the rotation filter 32) The light is incident on the second lens 34 via the filters 33a to 33d, is collected by the second lens 34, and is supplied to the end face of the light guide.
[0021]
As shown in FIG. 2, the rotary filter 32 has filters 33a, 33b, 33c, and 33d having different characteristics attached to four openings provided in a circumferential direction of a disk-shaped frame, and the center thereof is a motor 35. Filter 33i (i = a, b, c, d) arranged on the optical path (as if it is inserted / removed) by applying a drive signal to the motor 35 and changing the rotation angle. Can be selected and set.
[0022]
The rotation of the motor 35 is controlled by a control signal from a filter control circuit 36 to which a determination signal determined by the CCD determination circuit 26 is input. That is, the filter control circuit 36 controls the rotation of the motor 35 so that the filter optimal for the CCD 17 determined by the determination signal is arranged on the optical path.
[0023]
FIGS. 3A to 3D show characteristic examples of the filters 33a to 33d.
The filter 33a is a filter that transmits all visible light (about 380 nm to about 780 nm) flat as shown in FIG.
[0024]
The filters 33b to 33d are filters corresponding to filters having different spectral characteristics of the CCD 17 as shown in FIGS. 3B to 3D. Specifically, the filters in FIG. FIG. 3C shows a filter having a high transmittance in a region of about 380 nm to about 500 nm, and a filter having a high transmittance particularly in a green area of about 500 nm to about 580 nm. D) is a filter having a high transmittance especially in the red (about 580 nm to about 780 nm) region.
[0025]
These filters 33b to 33d are configured such that filters arranged to be inserted into and removed from the illumination optical path are selected by a signal from the CCD discriminating circuit 26.
Specifically, for example, when the spectral characteristics of the CCD 17 are low in the blue region (compared to the red and green regions) and the sensitivity is low, the CCD of that type is discriminated by the CCD discriminating circuit 26. The filter 33b is controlled so as to be arranged on the illumination optical path by the determination signal.
[0026]
If the spectral characteristics of the CCD 17 are low in the green or red region, the control is performed so that the filters 33c and 33d are arranged on the illumination light path. If the spectral characteristics of the CCD 17 have flat characteristics in the visible region, control is performed so that the filter 33a is arranged on the illumination light path.
[0027]
In this way, by optimizing the spectral characteristics of the illumination light that actually illuminates the subject side to be imaged by the CCD 17 according to the spectral characteristics of the CCD 17, the correction is performed in a state where the S / N is better than when electrically corrected. can do.
[0028]
Supplementary explanation, when the illumination side and the imaging side are considered, according to the present embodiment, it is possible to set the optimal spectral characteristic state and set the illumination and imaging environment.
That is, since the spectral characteristics on the imaging side are determined by the actually used CCD, it is necessary to perform correction on the illumination side or on the captured signal in order to obtain a captured image with a natural color tone. By supplying an appropriate illuminating light for compensating the characteristics of the CCD on the illuminating side, it is possible to obtain a good image with a better S / N than when performing color correction on a captured signal. .
[0029]
For example, if the spectral characteristics of the CCD 17 are low in the blue region (compared to the red and green regions) and the sensitivity is low, the filter 33b is arranged on the optical path. The filter having the same characteristic as the filter 33a is used, and the gain of the signal in the blue region is increased by color correction with respect to the captured signal.
[0030]
On the other hand, by increasing the blue illumination intensity in the illumination light amount on the illumination side, a natural tone can be achieved without increasing the gain of the signal in the blue region with respect to the captured signal, that is, white balance is achieved. S / N can be increased.
[0031]
Therefore, according to the present embodiment, when a video scope 2A or 2B having different characteristics of the CCD 17 as a color imaging unit is connected to perform an endoscopic inspection, a signal that identifies the color imaging unit is provided on the illumination optical path. The filters to be arranged can be selected and set so as to correct the spectral characteristics of the color imaging means actually used and to supply illumination light having the optimal spectral characteristics, and since the colors are not electrically balanced, the S / N is reduced. It is possible to obtain an excellent optimal image.
[0032]
In the first embodiment, a selection switch 37 is provided in the light source device 3 as shown in FIG. 1, and a filter arranged on the illumination optical path can be controlled via the filter control circuit 36 by the selection signal. Modifications may be used.
[0033]
More specifically, the user performs a selection operation with the selection switch 37 to generate a selection signal. The selection signal is input to the filter control circuit 36, and the filter control circuit 36 responds to the selection signal by the selection switch 37. Controls a filter arranged on the illumination light path.
[0034]
That is, the filter disposed on the illumination optical path can be controlled by the discrimination signal of the CCD discrimination circuit 26. For example, when a video scope without the CCD information generation unit 25 (for example, an old video scope) is used, The user can check the spectral characteristics of the CCD built in the video scope and operate the selection switch 37 so that a filter optimal for the spectral characteristics is arranged on the illumination light path.
[0035]
(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. An endoscope system 41 shown in FIG. 4 includes a video scope 42A, a light source device 43 according to the second embodiment that supplies illumination light to the video scope 42A, and a signal to a color imaging unit built in the video scope 42A. It is composed of a TV camera device 44 that performs processing and a color monitor 5 that displays a corresponding endoscope image by receiving a video signal from the TV camera device 44.
[0036]
Further, a video scope 42B shown by a two-dot chain line in FIG. 4 which incorporates a color imaging means having a different color imaging characteristic from the video scope 42A is connected to the light source device 43 and the TV camera device 44 instead of the video scope 42A. Endoscopy can also be performed.
[0037]
Hereinafter, since the configuration is similar to that of the endoscope system 1 of FIG. 1, only different portions will be described.
A video scope 42A in this endoscope system 41 has a CCD & scope information generation section 25 'that allows the type of the video scope 2A to be determined together with the CCD information, instead of the CCD information generation section 25 of FIG. Built-in.
[0038]
In response, the TV camera device 44 incorporates a CCD & scope discriminating circuit 46 instead of the CCD discriminating circuit 26 of FIG. It is input to the circuit 36 '.
[0039]
The light source device 43 employs a rotary filter 32 'shown in FIG. 5 instead of the rotary filter 32 shown in FIG. The rotary filter 32 'further includes filters 33e and 33f in addition to the filters 33a to 33d shown in FIG.
For example, as shown in FIG. 6A, the filter 33e is provided with a uniform interference film 52 on a transparent substrate 51. For example, the transmission characteristic of the filter 33e is almost the same as that of the filter 33a and does not depend on the place. However, the thickness of the interference film 52 is set to be larger and the transmission intensity is set to be smaller.
[0040]
That is, while the filter 33a efficiently transmits light in a predetermined wavelength range of the illumination light, when the filter 33e is disposed on the optical path, the amount of light transmitted therethrough is lower than in the case of the filter 33a.
[0041]
Therefore, when the light guide 12 is thin, the filter 33a is used to enable illumination light, and when the light guide 12 is thick and can sufficiently transmit the illumination light, the filter 33e is used. Thus, illumination with an appropriate illumination light amount can be performed.
[0042]
Also, as shown in FIG. 6B, the filter 33f reduces the thickness of the interference film 52 on the transparent substrate 51 at the central portion thereof as compared with the peripheral portion thereof, and reduces the incident light at the central portion. The transmission is set to be good, and the transmittance is set to be lower on the peripheral side than on the center side.
[0043]
By doing so, the irradiation characteristics of the illumination light by the lamp 23 can be corrected.
A discharge lamp is widely used as the lamp 23. Due to its structure, the illumination characteristics of the illumination light by the discharge lamp have such a light distribution characteristic that the electrodes are arranged on the emission side of the illumination light to form a shadow of the illumination and the center becomes dark.
[0044]
That is, as shown in FIG. 7, near the center (the emission angle is near 0 °), the intensity of the illumination light is reduced due to the electrodes. In the case of this illumination light, depending on the illumination optical system of the video scope, the illumination light affected by the illumination light may be emitted toward the subject.
[0045]
This characteristic can be improved by employing the filter 33f shown in FIG. As described with reference to FIG. 6B, in the filter 33f, a large amount of light passes through the central portion of the interference film 52, and the periphery has a low transmittance. Therefore, as shown in FIG. Can be light.
[0046]
Therefore, in the case of a lamp that emits illumination light having characteristics as shown in FIG. 7, by disposing the filter 33f on the illumination light path, it is possible to convert the light into illumination light having good light distribution characteristics, and uneven light distribution intensity. It is possible to illuminate the subject side in a nearly uniform state without any occurrence.
[0047]
In the present embodiment, in the case of the first embodiment, a filter that can be further arranged on the illumination light path is added so that the spectral intensity (brightness) and the light distribution can be changed. The most suitable filter can be selected and used for the type of CCD or CCD.
[0048]
For example, in the case of a video scope having a large diameter (using a light guide) with sufficient brightness, an extreme amount of light is not required, and conversely, a large amount of light may cause adverse effects such as halation on a subject. Come out. In this case, by selecting and using the filter 33e, the overall spectral intensity can be reduced, and the optimum illumination light amount can be obtained.
[0049]
Further, as described above, in the case of a lamp that emits illumination light having characteristics as shown in FIG. 7, illumination light having optimal light distribution characteristics can be supplied by using the filter 33f.
This embodiment has the following effects.
[0050]
By providing a plurality of filters according to the characteristics of the color image sensor, it is possible to supply illumination light capable of obtaining an image having an excellent S / N compared to a case where the color balance is electrically obtained. Can be. Further, by selecting a plurality of types of filters that can change the spectral intensity and the light distribution characteristics according to the type of the videoscope, it is possible to supply illumination light that can obtain an optimal endoscope image.
[0051]
In the second embodiment, for example, the filter 33f provided on the rotary filter 32 'may be provided on the second rotary filter (not shown). For example, a second rotation filter is arranged between the lenses 31 and 34 together with the rotation filter 32 ', so that the rotation of the second rotation filter can also be controlled by a motor 35 (not shown).
[0052]
The second rotating filter has, for example, at least a transparent window (that allows illumination light to pass through) in addition to the filter 33f. When the lamp 23 is of a discharge type and has the characteristics shown in FIG. 7, the filter 33f is arranged on the illumination light path. The light passing through this filter 33f may be further guided to the rotation filter 32 'side, and a filter arranged on the illumination light path may be selected according to the spectral characteristics of the CCD 17. Further, the filter 33e may be provided on the second rotary filter side.
In addition, the second rotary filter or the like is not limited to a filter that is arranged so that the filter is inserted into and removed from the illumination optical path by rotation. You may adopt it.
[0053]
In the above-described embodiments, the discriminating means such as the CCD discriminating circuit 26 is provided on the TV camera device side, but may be provided on the light source device 3 side. For example, a CCD information generating unit is provided in the connector 15 of FIG. 1, the type of the CCD 17 is determined from the information of the CCD information generating unit, and the determination signal is input to the filter control circuit 36 to be arranged on the illumination optical path. The filter may be controlled.
[0054]
In this case, for example, a bar code for identifying the type of CCD or the like is attached to a light guide base portion of the connector 15 inserted into the light source device 3 and the bar code is read by a bar code reader provided inside the light source device 3. Alternatively, a signal read by a bar code reader may be input to the filter control circuit 36.
A combination of the above-described embodiments and the like in a partial manner also belongs to the present invention.
[0055]
【The invention's effect】
As described above, according to the present invention, in a light source device used with a plurality of types of color imaging units having different spectral characteristics,
A plurality of types of optical filters respectively corresponding to the plurality of types of color imaging means,
Filter insertion / removal means capable of selectively inserting / removing the plurality of types of optical filters on the optical axis of a light source lamp capable of generating illumination light,
Control means for controlling the filter insertion / removal means based on a determination result of the determination means for determining the color imaging means to be used;
, Illumination light can be supplied by selecting an optical filter having an optimal or appropriate spectral characteristic for the spectral characteristic of the color imaging means actually used, and an image with a good S / N ratio can be obtained. Illumination light can be supplied.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an endoscope system including a first embodiment of the present invention.
FIG. 2 is a front view showing a filter configuration of a rotary filter.
FIG. 3 is a diagram illustrating filter characteristics of first to fourth filters provided in a rotary filter.
FIG. 4 is an overall configuration diagram of an endoscope system including a second embodiment of the present invention.
FIG. 5 is a front view showing a filter configuration of a rotary filter.
FIG. 6 is a sectional view showing the structure of a filter.
FIG. 7 is a characteristic diagram of illumination light emitted to a discharge type lamp.
FIG. 8 is a characteristic diagram of illumination light whose light distribution characteristics are improved by a filter.
[Explanation of symbols]
1. Endoscope system 2A, 2B ... Videoscope (electronic endoscope)
3: Light source device 4: TV camera device (camera control unit)
5. Color Monitor 10 Insertion Unit 12 Light Guide 13 Light Guide Cable 17 CCD
18, tip 23, lamp 25, CCD information generator 26, CCD discriminating circuit 32, rotary filters 33a to 33d, filter 35, motor 36, filter control circuit

Claims (3)

In a light source device used with a plurality of types of color imaging means having different spectral characteristics,
A plurality of types of optical filters respectively corresponding to the plurality of types of color imaging means,
Filter insertion / removal means capable of selectively inserting / removing the plurality of types of optical filters on the optical axis of a light source lamp capable of generating illumination light,
Control means for controlling the filter insertion / removal means based on a determination result of the determination means for determining the color imaging means to be used;
A light source device comprising: 2. The light source device according to claim 1, wherein the plurality of types of optical filters have different characteristics according to a type of a color imaging unit or an endoscope. In a light source device used with a plurality of types of color imaging means having different spectral characteristics,
A plurality of types of optical filters respectively corresponding to the plurality of types of color imaging means,
Filter insertion / removal means capable of selectively inserting / removing the plurality of types of optical filters on the optical axis of a light source lamp capable of generating illumination light,
Determining means for determining the color imaging means to be used;
Control means for controlling the filter insertion / removal means based on a result of the determination by the determination means;
A light source device comprising:

Images