JP5550574B2 - Electronic endoscope system - Google Patents

Description

  The present invention relates to an electronic endoscope system that captures an image of a subject with an electronic endoscope.

  In the medical field, diagnosis and treatment using an electronic endoscope are widespread. 2. Description of the Related Art In an electronic endoscope system that captures an image of a subject with an electronic endoscope, a mode is known in which imaging is performed by irradiating white light (hereinafter referred to as normal light) into the subject. However, there are cases in which it is difficult to grasp the tissue properties or the like in an image taken by irradiating normal light. For this reason, in recent years, electronic endoscopes have been known that shoot images that make it easier to grasp specific tissue properties by shooting while irradiating light in a specific narrow wavelength band (hereinafter referred to as special light). Yes. For example, in special light observation that observes by irradiating special light, the contrast between a specific tissue that absorbs special light well and other tissues becomes clearer, so it is more than normal light observation that observes by irradiating normal light. The specific tissue that absorbs special light is highlighted.

  In addition, a technique for highlighting and displaying a specific tissue by performing image processing for improving the contrast of the specific tissue on a captured image is known. For example, by performing image processing (hereinafter referred to as frequency enhancement processing) that enhances an image of a predetermined frequency on a captured image, a mucosal surface blood vessel (hereinafter referred to as a surface blood vessel) or a mid-depth blood vessel (hereinafter referred to as a mid-depth layer) It is known that the contrast of blood vessels) can be improved (Patent Document 1).

JP 2000-148987 A

  Special light observation emphasizes a specific tissue that absorbs special light well, but other normal tissues are observed in substantially the same manner as normal light observation. For this reason, the specific tissue that absorbs special light well is displayed in a state of being superimposed on the tissue that can be observed even in normal light observation.

  For example, in normal light observation, both superficial blood vessels and mid-deep blood vessels are observed, so if special light observation using special light that is well absorbed by superficial blood vessels to emphasize superficial blood vessels is performed, superficial blood vessels and The superficial blood vessels are emphasized in a state where the mid-deep blood vessels are superimposed. Therefore, even when it is desired to observe the superficial blood vessels precisely, the superimposed middle-deep blood vessels may interfere with the observation of the superficial blood vessels.

  This is also the case when special light observation using special light that is well absorbed by the middle-deep blood vessel is performed to emphasize the middle-deep blood vessel. Blood vessels are highlighted. Therefore, even when it is desired to observe the mid-deep blood vessel precisely, the superposed surface blood vessel may interfere with the observation of the mid-deep blood vessel.

  On the other hand, the frequency enhancement process is an enhancement process for improving the contrast of an image of a specific frequency, and is often used for an image photographed during special light observation. However, depending on the photographing distance, the target tissue may not be emphasized correctly. is there.

  Specifically, when the shooting distance is long, the mid-deep blood vessels are projected finely, so that the mid-deep blood vessels are emphasized, not the superficial blood vessels, despite the frequency enhancement processing that emphasizes the superficial blood vessels. May end up. Similarly, when the imaging distance is close, the superficial blood vessels are projected thickly, so that the superficial blood vessels are emphasized, not the mid-deep blood vessels, even though the frequency emphasis processing for emphasizing the mid-deep blood vessels is performed. There are times when it falls.

  As described above, both the superficial blood vessels and the mid-deep blood vessels are shown even during special light observation, so if the unintended blood vessel is emphasized by the frequency enhancement processing, the blood vessel to be observed becomes difficult to observe. May end up.

  For these reasons, in recent years, there has been a demand for further improving the visibility of blood vessels to be observed without being obstructed by other blood vessels.

  The present invention has been made in view of the above points, and an object thereof is to appropriately improve the visibility of a blood vessel to be observed without being obstructed by other blood vessels.

An electronic endoscope system according to the present invention includes a plurality of narrowband filters that transmit white light limited to narrowband light, and illumination light irradiating means that sequentially irradiates a living tissue in a body cavity with a plurality of colors of illumination light. Imaging the living tissue for each color under the illumination light of the plurality of colors, and outputting a color signal of each color as an imaging signal, and generating a display image based on the imaging signal output by the imaging means Display image generating means for adding a color signal having a high contrast of a non-observed blood vessel among surface blood vessels and middle-deep blood vessels to another color signal having a low contrast of the non-observed blood vessel, Suppression means for suppressing display of the non-observation target blood vessel with respect to the observation target blood vessel by reducing contrast of the target blood vessel.

  The suppression means changes an addition ratio according to a preset parameter when adding a color signal having a low contrast of the non-observation target tissue to a color signal having a high contrast of the non-observation target blood vessel. Accordingly, it is preferable to change the degree of suppressing the display of the non-observation target blood vessels.

  As the narrowband filter, a first narrowband filter for obtaining a color signal with a high contrast of the surface blood vessel, a second narrowband filter for obtaining a color signal with a high contrast of the mid-depth blood vessel, and the surface blood vessel And a third narrow-band filter for obtaining a color signal having a low contrast between the middle-deep blood vessels.

  When the observation target blood vessel is the middle-deep blood vessel and the non-observation target blood vessel is a surface blood vessel, the suppression unit transmits the first illumination light irradiated through the first narrowband filter. An intermediate signal is generated by adding the third color signal obtained under the third illumination light irradiated through the third narrowband filter to the first obtained color signal. The display image uses the intermediate signal and the second color signal obtained under the second illumination light irradiated through the second narrowband filter for each pixel. Is preferably generated.

When the observation target blood vessel is the surface blood vessel and the non-observation target blood vessel is a mid-deep blood vessel, the suppression means transmits the second narrowband filter and irradiates the second illumination light. An intermediate signal is generated by adding the third color signal obtained under the third illumination light irradiated through the third narrowband filter to the second color signal obtained originally. The display image uses the intermediate signal and the first color signal obtained under the first illumination light irradiated through the first narrow-band filter for each pixel. Preferably an image is generated.

  It is preferable to include an enhancement processing means for performing an enhancement process for enhancing the blood vessel to be observed on the display image.

  Preferably, the suppression means suppresses display of the non-observation target blood vessels in conjunction with selection of the observation target blood vessels to be emphasized by the enhancement processing means.

  Preferably, the display image generation unit generates the display image by using the blue imaging signal for the blue pixel and the green pixel and using the green imaging signal for the red pixel.

  It is preferable to include a color tone correction unit that corrects the color tone of the display image.

  According to the present invention, the visibility of a blood vessel to be observed can be appropriately improved without being obstructed by an image of another tissue.

It is an external view which shows the structure of an electronic endoscope system. It is a block diagram which shows the electric constitution of an electronic endoscope system. It is explanatory drawing which shows the aspect which produces | generates special light image data from an imaging signal. It is a schematic diagram of a surface blood vessel and a middle-deep blood vessel projected on special light image data. It is explanatory drawing which shows the aspect which suppresses the display of a middle-deep-layer blood vessel. It is a schematic diagram of the special light image data which suppressed the display of the middle depth blood vessel. It is explanatory drawing which shows the color tone of middle depth blood-vessel suppression image data. It is explanatory drawing which shows the aspect which correct | amends the color tone of middle depth blood-vessel suppression image data. It is explanatory drawing which shows the aspect which correct | amends the color tone of middle depth blood-vessel suppression image data. It is explanatory drawing which shows the aspect which correct | amends the color tone of middle depth blood-vessel suppression image data. It is a block diagram which shows the electric constitution of the electronic endoscope system of 2nd Embodiment. It is a graph which shows the aspect of excitation light emission by fluorescent substance. It is explanatory drawing which shows the example which suppressed the display of the surface blood vessel. It is explanatory drawing which shows the color tone of surface layer blood vessel suppression image data. It is explanatory drawing which shows the aspect which correct | amends the color tone of surface blood-vessel suppression image data. It is explanatory drawing which shows the aspect which correct | amends the color tone of surface blood-vessel suppression image data. It is explanatory drawing which shows the aspect which correct | amends the color tone of surface blood-vessel suppression image data. It is a block diagram which shows the structure of the light source device of another aspect. It is a graph which shows the reflectance of a mucous membrane, a surface blood vessel, and a mid-deep blood vessel. It is a block diagram which shows the structure of the light source device of another aspect. It is a block diagram which shows the structure of the electronic endoscope system of 3rd Embodiment. It is explanatory drawing which shows an example of GUI which performs the setting of a suppression display. It is explanatory drawing which shows an example of GUI which performs the setting of an emphasis display. It is a block diagram which shows the structure of the electronic endoscope system of 5th Embodiment. It is explanatory drawing which shows the structure of a rotation filter. It is explanatory drawing which shows the aspect which produces | generates special light image data. It is explanatory drawing which shows the aspect which produces | generates middle depth blood-vessel suppression image data. It is explanatory drawing which shows the aspect which produces | generates surface layer blood vessel suppression image data. It is explanatory drawing which shows the example which provides a rotary filter so that replacement | exchange is possible. It is explanatory drawing which shows the example which provides a rotary filter so that replacement | exchange is possible.

[First Embodiment]
As shown in FIG. 1, the electronic endoscope system 11 includes an electronic endoscope 12, a processor device 13, and a light source device 14. The electronic endoscope 12 is connected to a flexible insertion portion 16 that is inserted into the body of a subject, an operation portion 17 that is connected to a proximal end portion of the insertion portion 16, a processor device 13, and a light source device 14. Connector 18 and a universal cord 19 that connects between the operation unit 17 and the connector 18. At the distal end (hereinafter referred to as the distal end portion) 20 of the insertion portion 16, there is a CCD type image sensor (see FIG. 2; hereinafter referred to as CCD) 21 for imaging a living tissue in the body cavity (hereinafter referred to as the subject). Is provided.

  The operation unit 17 includes an angle knob for bending the tip 20 up and down, left and right, an air / water feed button for ejecting air and water from the tip of the insertion unit 16, and a release for recording a still image. Operation members such as a button, a zoom button for instructing enlargement / reduction of the observation image displayed on the monitor 22, and a switching button for switching between normal light observation and special light observation are provided.

  The processor device 13 is electrically connected to the light source device 14 and comprehensively controls the operation of the electronic endoscope system 11. The processor device 13 supplies power to the electronic endoscope 12 via the universal cord 19 and a transmission cable inserted into the insertion portion 16 and controls the driving of the CCD 21. In addition, the processor device 13 acquires an imaging signal output from the CCD 21 via a transmission cable, and performs various image processing to generate image data. The image data generated by the processor device 13 is displayed as an observation image on a monitor 22 connected to the processor device 13 by a cable.

  As shown in FIG. 2, the distal end portion 20 is provided with an objective optical system 31, a CCD 21, a light projecting unit 41, and the like. A timing generator (hereinafter referred to as TG) 32, an analog signal processing circuit (hereinafter referred to as AFE) 33, and a CPU 34 are provided in the operation unit 17, the connector 18, and the like.

  The objective optical system 31 includes a lens, a prism, and the like, and forms an image on the CCD 21 with light from within the subject incident through the observation window 36.

  The CCD 21 photoelectrically converts the image in the subject imaged on the imaging surface by the objective optical system 31 for each pixel, and accumulates signal charges corresponding to the amount of incident light. The CCD 21 outputs the signal charge accumulated in each pixel as an imaging signal. The CCD 21 is formed with a color filter composed of a plurality of color segments in each pixel. The color filter of the CCD 21 is, for example, a primary color (RGB) color filter in a Bayer array.

  The TG 32 inputs a clock signal to the CCD 21. Based on the clock signal input from the TG 32, the CCD 21 performs an accumulation operation for accumulating signal charges and a read operation for reading signal charges at a predetermined timing. The clock signal output from the TG 32 is controlled by the CPU 34.

  The AFE 33 includes a correlated double sampling (CDS) circuit, an automatic gain adjustment (AGC) circuit, and an A / D conversion circuit. After obtaining an analog imaging signal from the CCD 21 while removing noise, and after performing gain correction processing, It converts into a digital signal and inputs into DSP52. The CDS circuit acquires an imaging signal while removing noise generated by driving the CCD 21 by correlated double sampling processing. The AGC circuit amplifies the imaging signal input from the CDS circuit. The A / D conversion circuit converts the imaging signal input from the AGC circuit into a digital imaging signal having a predetermined number of bits, and inputs the digital imaging signal to the DSP 52. The driving of the AFE 33 is controlled by the CPU 34. For example, the CPU 34 adjusts the gain (gain) of the imaging signal by the AGC circuit based on the signal input from the CPU 51 of the processor device 13.

  The light projecting unit 41 is a unit that irradiates illumination light into the subject. Normal light and special light are both emitted from the light projecting unit 41 as illumination light. As will be described later, the light projecting unit 41 irradiates the subject with normal light and special light simultaneously.

The light projecting unit 41 includes a fluorescent body 43 and guides blue laser light and blue-violet laser light from the light source device 14 by a light guide 42 made of an optical fiber. The phosphor 43 is a phosphor that absorbs a part of blue laser light or blue-violet laser light and emits light by excitation from green to yellow. For example, the phosphor 43 includes a YAG phosphor, a BAM (BaMgAl ₁₀ O ₁₇ ) phosphor, and the like. Become. The blue laser light and blue-violet laser light guided to the light projecting unit 41 are partly absorbed by the phosphor 43, thereby causing green to yellow fluorescence to be emitted from the phosphor 43, and part of the phosphor 43 is transmitted. Accordingly, the light projecting unit 41 irradiates the subject with pseudo white light (normal light) in which green to yellow fluorescence emitted from the phosphor 43 and blue light transmitted through the phosphor 43 are combined as illumination light. At the same time, the blue light and blue-violet light transmitted through the phosphor 43 also act as special light, as will be described later.

  Note that the phosphor 43 has excitation and emission efficiency different between blue laser light and blue-violet laser light, and the blue laser light generates more fluorescence than the blue laser light if the incident light amount is the same. In addition, since the blue laser light transmitted through the phosphor 43 is diffused by the phosphor 43, the normal light emitted from the light projecting unit 41 is uniform within the field of view of the electronic endoscope 12.

  The processor device 13 includes a CPU 51, a digital signal processing circuit (DSP) 52, a digital image processing circuit (DIP) 53, a display control circuit 54, an operation unit 56, and the like.

  The CPU 51 is connected to each unit via a data bus, an address bus, and a control line (not shown), and comprehensively controls the entire processor device 13. The ROM 57 stores various programs (OS, application programs, etc.) for controlling the operation of the processor device 13 and various data such as graphic data. The CPU 51 reads necessary programs and data from the ROM 57, develops them in the RAM 58, which is a working memory, and sequentially processes the read programs. In addition, the CPU 51 obtains information that changes for each examination such as examination date and time, character information such as subject and operator information from the operation unit 56 and a network such as a LAN, and stores the information in the RAM 58.

  The DSP 52 generates image data by performing various signal processing such as color separation, color interpolation, gain correction, white balance adjustment, and gamma correction on the imaging signal input from the CCD 21 via the AFE 33.

  When performing normal light observation, the DSP 52 outputs, as image data, a blue image pickup signal (hereinafter referred to as B signal) output from the blue pixel of the CCD 21 to a blue pixel (hereinafter referred to as B pixel) from the green pixel. A green imaging signal (hereinafter referred to as G signal) is applied to a green pixel (hereinafter referred to as G pixel), and a red imaging signal (hereinafter referred to as R signal) output from a red pixel is applied to a red pixel (hereinafter referred to as R pixel). The assigned normal light image data is generated. On the other hand, when performing special light observation, the DSP 52 generates special light image data in which the B signal is assigned to the B pixel and the G pixel and the G signal is assigned to the R pixel as the image data. In this case, the R signal is discarded unless a suppression display processing unit 60 described later is functioning.

  Furthermore, the DSP 52 includes a suppression display processing unit 60 that generates middle-deep blood vessel suppression image data. The mid-deep blood vessel suppression image data is image data generated at the time of special light observation, in which a B signal is assigned to the B pixel and the G pixel, and a signal value obtained by adding the R signal to the G signal is assigned to the R pixel. The addition rate of the R signal added to the G signal as the pixel value of the R pixel is determined by setting. Specifically, the degree of inhibition indicating how much the mid-deep blood vessel display is to be suppressed is set in advance as a parameter for image processing, and the larger the set degree of inhibition, the more R signals to be added. The smaller R is, the fewer R signals are added. Further, the suppression display processing unit 60 functions when it is selected to suppress the display of the middle-deep blood vessel by setting.

  The image data generated by the DSP 52 is input to the working memory of the DIP 53. Also, the DSP 52 generates ALC control data necessary for automatic control (ALC control) of the amount of illumination light, such as an average luminance value obtained by averaging the luminance of each pixel of the generated image data, and inputs the data to the CPU 51.

  The DIP 53 is a circuit that performs various types of image processing such as electronic scaling and enhancement processing on the image data generated by the DSP 52. Image data that has been subjected to various image processing by the DIP 53 is temporarily stored in the VRAM 59 as an observation image, and then input to the display control circuit 54.

  Of the various image processes performed by the DIP 53, the emphasis process is specifically a frequency emphasis process, and is performed as necessary by setting. The DIP 53 increases the pixel value of the image in the predetermined frequency band according to the tissue property of the target to be emphasized, such as when emphasizing the superficial blood vessel or when emphasizing the middle-deep blood vessel, thereby Improve the contrast. By improving the contrast of the image in the frequency band predetermined for the superficial blood vessel, the superficial blood vessel is enhanced. Similarly, the mid-deep blood vessel is enhanced by improving the contrast of the frequency band predetermined for the mid-deep blood vessel. However, when the imaging distance (distance from the distal end portion 20 to the mucous membrane in the subject) is long, the mid-deep blood vessel is also projected finely, so that the mid-deep blood vessel is emphasized even if the frequency enhancement process for superficial blood vessel enhancement is performed. In some cases, when the imaging distance is short, even a superficial blood vessel is displayed thick, so that the superficial blood vessel may be emphasized even if the frequency emphasis processing for emphasizing the mid-deep blood vessel is performed.

  The display control circuit 54 acquires an observation image from the VRAM 59 and receives graphic data and the like stored in the ROM 57 and the RAM 58 from the CPU 51. Examples of the graphic data include a display mask for displaying only an effective pixel region in which an object is photographed in an observation image, information such as names of subjects and surgeons, character information such as examination date and time, and GUI. The display control circuit 54 superimposes graphic data or the like on the observation image, converts it to a video signal (component signal, composite signal, etc.) according to the display format of the monitor 22, and outputs it to the monitor 22. Thereby, an observation image is displayed on the monitor 22.

  The operation unit 56 is a known input device such as an operation panel, a mouse, or a keyboard provided in the housing of the processor device 13. The CPU 51 operates each unit of the electronic endoscope system 11 according to an operation signal input from the operation unit 56 or the operation unit 17 of the electronic endoscope 12.

  In addition to the above, the processor device 13 includes a compression processing circuit that performs image compression processing on image data in a predetermined compression format (for example, JPEG format), and an image compressed in conjunction with the operation of the release button. A network I / F and the like for transmitting various data to and from a network such as a media I / F and a LAN. These are connected to the CPU 51 via a data bus or the like.

  The light source device 14 has two laser diodes, a blue LD 66 and a blue-violet LD 67, as light sources.

  The blue LD 66 emits blue laser light having a center wavelength of 445 nm. The blue laser light emitted from the blue LD 66 is guided to the light projecting unit 41 through the connector 18 and the light guide 42, and is incident on the phosphor 43 to be irradiated into the subject as pseudo white normal light. . Further, the blue laser light is diffused when passing through the phosphor 43 and is irradiated into the subject as blue light. This blue light is stronger than the fluorescence emitted by the phosphor 43 and acts as special light that is well absorbed by blood in the surface blood vessels.

  The blue-violet LD 67 emits blue-violet laser light having a center wavelength of 405 nm. The blue-violet laser light emitted from the blue-violet LD 67 is combined with the blue laser light by the coupler 69 and guided to the light projecting unit 41 through the connector 18 and the light guide 42 in the same manner as the blue laser light. The blue-violet laser light is incident on the phosphor 43 and becomes pseudo white normal light and is irradiated into the subject, but the amount of light is generally smaller than that of the blue laser light. Further, blue-violet light that is diffused and transmitted by the blue-violet laser light by the phosphor 43 acts as special light, like blue light.

  The light emission timing and light emission amount of the blue LD 66 and the blue-violet LD 67 are controlled by the CPU 68. For example, the CPU 68 lights only the blue LD 66 when performing normal light observation, and lights both the blue LD 66 and the blue-violet LD 67 when performing special light observation. Further, the CPU 68 automatically controls the light emission amounts of the blue LD 66 and the blue-violet LD 67 in real time so that the light amount is appropriate for observation based on the ALC control data input from the CPU 51 of the processor device 13.

  Regardless of whether the observation mode is normal light observation or special light observation, the electronic endoscope system 11 configured as described above lights up both the blue LD 66 and the blue-violet LD 67 to perform projection. White light and special light (blue light and blue-violet light) are simultaneously irradiated from the light unit 41 into the subject as illumination light. However, the light emission amount of the blue LD 66 and the blue-violet LD 67 and the light quantity ratio of these LD 66 and 67 are either normal light observation or special light observation, or emphasize the superficial blood vessels during special light observation or emphasize the mid-deep blood vessels. It is adjusted depending on whether etc.

  During normal light observation, the electronic endoscope system 11 generates normal light image data by using the B signal output from the CCD 21 for the B pixel, the G signal for the G pixel, and the R signal for the R pixel. The normal light image data is subjected to various image processing according to the setting by the DIP 53, and then the graphic data and the like are superimposed by the display control circuit 54 and displayed on the monitor 22.

  On the other hand, as shown in FIG. 3, the electronic endoscope system 11 uses the B signal output from the CCD 21 for the B pixel and the G pixel and the G signal for the R pixel at the time of special light observation. Is generated. As described above, the special light image data generated by using the B signal for the B pixel and the G pixel and the G signal for the R pixel is image data in which the blood vessel is emphasized more than the normal light image data. This is because hemoglobin contained in blood has a light absorption peak in the wavelength band of blue light or green light, and the B signal or G signal corresponding thereto improves blood vessel contrast. The special light image data is subjected to various image processing according to the setting by the DIP 53, and then the graphic data and the like are superimposed on the display control circuit 54 and displayed on the monitor 22.

  As illustrated in FIG. 4, the special light image data 71 is, for example, image data in which the surface blood vessels 72 are emphasized and imaged. On the other hand, the mid-deep blood vessel 73 is also shown in the special light image data 71. For this reason, although the superficial blood vessel 72 is emphasized, observation of the superficial blood vessel 72 may be hindered when the image of the middle-deep blood vessel 73 is superimposed and projected. Further, when frequency collection emphasis processing is performed on the special light image data 71 by the DIP 53, the middle-deep blood vessel 73 may be emphasized depending on the photographing distance, and the observation of the surface blood vessel 72 may be hindered. is there.

  In such a case, the electronic endoscope system 11 can suppress the display of the image of the mid-deep blood vessel 73 by setting the display of the mid-deep blood vessel 73 by operating the operation unit 56 or the like. . Specifically, by operating the operation unit 56 or the like, the suppression display setting of the middle-deep blood vessel 73 is turned on. At the same time, the degree of suppression indicating how much the display of the middle-deep blood vessel 73 is suppressed is set as a parameter for image processing. The degree of inhibition is set to a numerical value such as 1-100, for example. The larger the degree of inhibition, the more the image of the intermediate deep blood vessel 73 is displayed, and the smaller the degree of inhibition, the closer to the image where the intermediate deep blood vessel 73 is captured. Remain.

  When the suppression display setting of the middle-deep blood vessel 73 is turned on, the suppression display processing unit 60 functions when the DSP 52 generates the special light image data 71 from the imaging signal input from the CCD 21. In this case, as shown in FIG. 5, the DSP 52 uses the suppression display processing unit 60 to use the B signal output from the CCD 21 for the B pixel and the G pixel, and to add the signal value obtained by adding the R signal to the G signal to the R pixel. Middle deep blood vessel suppression image data is generated using the pixel value.

  Since the mid-deep blood vessel 73 is located deeper in the submucosa than the superficial blood vessel 72, it mainly absorbs green light having a high depth of penetration. For this reason, the middle deep blood vessel 73 is projected as the contrast of the G signal. On the other hand, the superficial blood vessel 72 is located at a shallower position than the middle-deep blood vessel 73 and easily absorbs blue light having a small depth of penetration, so that the superficial blood vessel 72 is mainly imaged as a B signal contrast. Further, since the red wavelength band is less absorbed by hemoglobin, the contrast of the surface blood vessel 72 and the middle-deep blood vessel 73 in the R signal is small.

  Therefore, in the mid-deep blood vessel suppression image data, a signal in which the component of the G signal is relatively reduced by adding the R signal having the low contrast of the mid-deep blood vessel 73 to the G signal having the high contrast of the mid-deep blood vessel 73. The value is used as the pixel value of the R pixel. As a result, as shown in FIG. 6, the mid-deep blood vessel suppression image data 74 becomes image data in which the contrast of the image of the mid-deep blood vessel 73 is lowered. On the other hand, since the superficial blood vessel 72 is mainly reflected in the B signal, it appears as the contrast of the image by the B pixel and the G pixel. Therefore, the superficial blood vessel 72 is emphasized in the mid-deep blood vessel suppression image data as well as the special light image data. Displayed as an image. For this reason, the visibility of the superficial blood vessel 72 is improved in the mid-deep blood vessel suppression image data 74.

  The suppression display processing unit 60 adjusts the addition rate of the R signal according to the set suppression degree. For example, the larger the suppression degree, the more R signals are added to the G signal. The more the R signal is added to the G signal, the lower the contrast of the image of the intermediate deep blood vessel 73 appearing in the G signal. Thereby, the mid-deep blood vessel 73 is displayed with the visibility according to the set suppression degree.

  Similarly to the special light image data 71, the intermediate deep blood vessel suppression image data 74 is subjected to various image processing by the DIP 53, and then the graphic data and the like are superimposed on the display control circuit 54 and displayed on the monitor 22. As described above, when the frequency enhancement processing is performed on the image data generated by the DSP 52 using the DIP 53, a tissue that is not the object of observation (here, the mid-deep blood vessel 73) may be emphasized depending on the imaging distance. In the suppression image data 74, the contrast of the intermediate deep blood vessel 73 is reduced in accordance with the degree of suppression. Therefore, even if the intermediate deep blood vessel 73 is emphasized by the frequency enhancement process, the influence of the special optical image data 71 is reduced. Less than the case.

  In the first embodiment described above, since the R signal is added to the G signal, the color tone of the mid-deep blood vessel suppression image data 74 changes with respect to the special light image data 71.

  For example, as shown in FIG. 7A, the signal value of each color of the CCD 21 is B signal: G signal: R signal = 300: 300: 150 when photographing under illumination light of a predetermined condition. And Further, the DSP 52 generates the special light image data 71 by adjusting the color tone from the image signals of these colors so as not to make the observation uncomfortable. Here, for the sake of simplicity, the signals of the BG (R) colors are used as they are. Are used for each pixel value of the special light image data 71. Then, the special light image data 71 becomes gray image data in which the pixel values of the B pixel, the G pixel, and the R pixel are all equal to 300.

  On the other hand, as shown in FIG. 7B, when the middle-deep blood vessel suppression image data 74 is generated under the illumination light under the same conditions, the pixel values of the B pixel and the G pixel are 300, and the special light image data However, the pixel value of the R pixel is 450 by adding the R signal to the G signal. For this reason, if the special light image data 71 is generated in the same manner as when the special light image data 71 is generated, the image data becomes reddish as a whole.

  For this reason, when generating the mid-deep blood vessel suppression image data 74, it is preferable to correct the color tone to be the same as that of the special light image data 71. Such tone correction can be performed, for example, in three modes described below.

  First, as shown in FIG. 8, before the generation of the mid-depth blood vessel suppression image data 74, the mid-depth blood vessel suppression image data 74 is suppressed so as to have a predetermined color tone (gray) with respect to the imaging signals of the BGR colors. By performing the gain correction taking the degree into consideration, the color tone of the mid-deep blood vessel suppression image data 74 can be corrected.

  When the inhibition level at which the G signal and the R signal are added at a ratio of 1: 1 is set at the time of generating the mid-depth blood vessel suppression image data 74, the signal value of the B signal is set to 200 and the signal of the R signal is set. Gain correction is performed to make the value 100. Therefore, since the signal value after gain correction is B signal: G signal: R signal = 300: 200: 100, when the mid-deep blood vessel suppression image data 74 is generated based on this, the mid-deep blood vessel suppression image data 74 is generated. The pixel value of each pixel is B pixel: G pixel: R pixel = 300: 300: 300. As a result, like the special light image data 71, the middle-deep blood vessel suppression image data 74 can be gray image data.

  The gain correction performed here may be performed by the AFE 33 at the stage where the imaging signal is output from the CCD 21 or may be performed on the imaging signal input from the CCD 21 by the DSP 52.

  In addition, as shown in FIG. 9, after the generation of the mid-deep blood vessel suppression image data 74, by performing a color tone conversion process for converting to the same color tone as the special light image data 71, You may correct a color tone. For example, the imaging signals of each color input from the CCD 21 are used as they are, and the mid-deep blood vessel suppression image data 74 corresponding to the set degree of suppression is generated. The mid-deep blood vessel suppression image data 74 generated here is reddish image data as described above. After that, the medium-deep blood vessel suppression image data 74 having a gray color tone is generated by performing a color tone conversion process for converting the pixel value of the R pixel to 300 with respect to the reddish middle-deep blood vessel suppression image data 74. .

  Further, as shown in FIG. 10, when the R signal is added to the G signal, the G signal and the R signal are multiplied by a coefficient α and a coefficient β, respectively, and then added together, whereby the pixel value of the R pixel is predetermined. Gray intermediate / deep blood vessel suppression image data 74 may be generated by adding the values so as to be 300 (here, 300). The coefficients α and β are predetermined according to the amount of illumination light, the degree of suppression, and the like. For example, the coefficients α and β are illumination light in which the ratio of the G signal to the R signal is 2: 1 (= 300: 150), and G In the case of the degree of suppression in which the signal and the R signal are added as they are, the coefficients α and β are both reduced to 2/3 in order to obtain the gray middle-layer blood vessel suppression image data 74 by setting the pixel value of the R pixel to 300. Set it.

  The tone correction processing performed as described above is easily realized by preparing a plurality of tone conversion look-up tables (LUTs) in advance according to the degree of suppression or the like, and using them according to the degree of suppression. be able to. In addition, when performing color tone correction processing by calculation, a plurality of matrices (MTX) to be used for calculation may be prepared. The same applies to the case where the color tone of the mid-deep blood vessel suppression image data 74 is corrected by gain correction. It is enough to have more than one. The same applies when the coefficients α and β are used.

  In the first embodiment described above, the example in which the suppression display processing unit 60 is caused to function to suppress the display of the middle-deep blood vessel 73 has been described. Similarly, the suppression display processing unit 60 displays the display of the surface blood vessel 72. It can also be suppressed. In the first embodiment described above, in order to suppress the display of the intermediate deep blood vessel 73, it is generated by adding the R signal with the low contrast of the intermediate deep blood vessel 73 to the G signal with the high contrast of the intermediate deep blood vessel 73. The contrast of the middle deep blood vessel 73 in the image data is reduced. Therefore, when the surface blood vessel 72 is suppressed and displayed by signal processing using the suppression display processing unit 60 in the same manner, an R signal or a G signal having a low contrast of the surface blood vessel 72 is added to the B signal having a high contrast of the surface blood vessel 72. Add. However, the suppression display by signal processing using the suppression display processing unit 60 is a mode suitable for the suppression display of the middle-deep blood vessel 73, and the suppression display of the surface blood vessel 72 is performed in the mode of the second embodiment described later. More preferred.

  In the above-described first embodiment, the example in which the middle-deep blood vessel 73 is suppressed and displayed has been described. However, the target for suppressing the display is not limited to the middle-deep blood vessel 73. For example, when it is desired to observe the middle deep blood vessel 73, it is preferable to suppress the display of the superficial blood vessel 72. Hereinafter, the example which suppresses the display of the surface blood vessel 72 as 2nd Embodiment is demonstrated. In addition, the same code | symbol is attached | subjected to the member similar to the electronic endoscope system 11 of the above-mentioned 1st Embodiment, and description is abbreviate | omitted.

[Second Embodiment]
As shown in FIG. 11, the electronic endoscope system 76 is a system that suppresses display of the superficial blood vessel 72 according to the setting, and includes a light amount ratio adjustment unit 77 in the CPU 68 of the light source device 14.

  The light amount ratio adjusting unit 77 adjusts the ratio of the light emission amounts of the blue LD 66 and the blue-violet LD 67 according to the light amount of the entire illumination light determined by the ALC control and the degree of suppression determined by the setting. Thereby, the spectrum of illumination light changes and the contrast of the surface blood vessel 72 is reduced. The degree of inhibition is a parameter indicating how much the display of the superficial blood vessel 72 is to be displayed, and is preset by, for example, inputting a numerical value. The light amount ratio adjusting unit 77 functions when the contrast of the surface blood vessel 72 is set to be reduced and the display of the surface blood vessel 72 is suppressed.

  Specifically, the light amount ratio adjustment unit 77 increases the light emission amount of the blue LD 66 relative to the blue-violet LD 67. The relative increase rate of the light emission amount of the blue LD 66 is determined according to the set degree of suppression. The light amount ratio adjustment of the blue LD 66 and the blue-violet LD 67 by the light amount ratio adjusting unit 77 is performed so that the light amount of the normal light emitted from the light projecting unit 41 becomes the light amount determined by the ALC control described above. For this reason, the adjustment of the light quantity ratio of the blue LD 66 and the blue violet LD 67 by the light quantity ratio adjusting unit 77 is performed depending on the state of ALC control. It is done in combination.

  The operation of the electronic endoscope system 76 during normal light observation or during special light observation that does not suppress the display of the surface blood vessels 72 is the same as that of the electronic endoscope system 11 of the first embodiment described above. On the other hand, when special light observation is performed and the display of the superficial blood vessel 72 is suppressed, the electronic endoscope system 76 operates as follows.

  When suppressing the display of the superficial blood vessel 72, first, the operation unit 56 and the like are operated to turn on the suppression display setting of the superficial blood vessel 72 and set the degree of suppression. The degree of inhibition is set to a numerical value such as 1-100, for example. The larger the degree of inhibition, the more the display of the image of the surface blood vessel 72 is suppressed, and the smaller the degree of inhibition, the closer to the image of the surface blood vessel 72 taken.

  Thus, when the suppression display setting of the superficial blood vessel 72 is turned on and the degree of suppression is set, the light amount ratio adjustment unit 77 functions. Thereby, the light emission amount of the blue LD 66 is relatively increased with respect to the light emission amount of the blue-violet LD 67 while the light amount of the normal light included in the illumination light is controlled to a predetermined light amount based on the ALC control.

  As shown by a solid line and a broken line in FIG. 12, the phosphor 43 emits fluorescence by exciting the blue laser light (405 nm) emitted from the blue-violet LD 67 and the blue-violet laser light (445 nm) emitted from the blue LD 66. The amount of light is different. Specifically, the blue-violet laser light incident from the blue LD 66 has better excitation light emission efficiency.

  For this reason, as shown by a two-dot chain line in FIG. 12, when the light emission amount of the blue LD 66 is increased, the component of the normal light included in the illumination light amount increases. As a result, the amount of blue light (405 nm) and blue-violet light (445 nm) that function as special light is reduced in the total amount of illumination light.

  Since the superficial blood vessel 72 is projected as the contrast of the B signal by absorbing the special light, if the proportion of the special light amount becomes smaller in the entire illumination light amount as described above, the superficial blood vessel 72 is The contrast of the image is lowered and the visibility is lowered. On the other hand, since the mid-deep blood vessel 73 is mainly projected as the contrast of the G signal, there is almost no change even if the light quantity ratio of the blue LD 66 and the blue-violet LD 67 is changed. For this reason, the mid-deep blood vessel 73 can be observed in substantially the same manner regardless of whether or not the light amount ratio adjusting unit 77 is functioning.

  For this reason, as shown in FIG. 13A, when the suppression display setting of the superficial blood vessel 72 is turned off, the superficial blood vessel 72 is superimposed on the middle deep blood vessel 73 in the special light image data 71, and the superficial blood vessel 72 is superposed. Although the blood vessel 72 may interfere with the observation of the mid-depth blood vessel 73, as shown in FIG. 13B, the special light image data 87 generated by turning on the suppression display setting of the surface blood vessel 72. In the following (hereinafter referred to as surface blood vessel suppression image data), the display of the surface blood vessels 72 is suppressed, and the visibility of the mid-deep blood vessels 73 is relatively improved.

  Depending on image processing settings, frequency enhancement processing may be performed on the surface blood vessel suppression image data 78 by the DIP 53. In this case, in the special light image data 71 in which the display of the superficial blood vessel 72 is not suppressed, the superficial blood vessel 72 is emphasized according to the photographing distance, although the mid-high blood vessel 73 is desired to be observed. May result in obstructing. However, in the superficial blood vessel suppression image data 78, the contrast of the superficial blood vessel 72 is reduced according to the degree of suppression. Less than in the case of the optical image data 71.

  In the second embodiment described above, the light intensity of the blue LD 66 and the blue-violet LD 67 is changed, so that the color tone of the surface blood vessel suppression image data 78 changes with respect to the special light image data 71.

  For example, as shown in FIG. 14A, the signal values of the respective colors of the CCD 21 are B signal: G signal: R signal = 500: 150: 100 when photographing is performed under illumination light of a predetermined condition. And Further, the DSP 52 generates special light image data by adjusting the color tone from the image signals of each color so as not to make the observation uncomfortable. Here, for simplicity, the signals of each color of the BG (R) are not changed. It is assumed that it is used for each pixel value of the special light image data 71 at a ratio. In this case, the ratio of the pixel value of each pixel of the special light image data 71 is B pixel: G pixel: R pixel = 500: 500: 150, and the special light image data 71 is cyan.

  On the other hand, as shown in FIG. 14B, the signal value of each color of the CCD 21 changes when the ratio of the light emission amounts of the blue LD 66 and the blue-violet LD 67 is changed while the light quantity as a whole of the illumination light is constant. Here, it is assumed that the light amount ratio adjustment unit 77 has changed to B signal: G signal: R signal = 500: 250: 170 by adjusting the ratio of the light emission amounts of the blue LD 66 and the blue-violet LD 67. In this case, the ratio of the pixel value of each pixel of the surface blood vessel suppression image data 78 is B pixel: G pixel: R pixel = 500: 500: 250, which is a lighter cyan color (whiter) than the special light image data 71. Become.

  For this reason, when the surface light vessel suppression image data 78 is generated by adjusting the ratio of the light emission amounts of the blue LD 66 and the blue-violet LD 67 by the light amount ratio adjusting unit 77, the same color tone as that of the special light image data 71 is obtained. It is preferable to correct so. The overtone correction can be performed in, for example, three modes described below.

  First, as shown in FIG. 15, before the surface blood vessel suppression image data 78 is generated, the surface blood vessel suppression image data 78 has a predetermined color tone (the same cyan color as that of the special light image data 71) with respect to the BGR image signals. ), The color tone of the surface blood vessel suppression image data 78 can be corrected by performing gain correction that takes into account the degree of suppression. The gain correction performed here may be performed by the AFE 33 at the stage where the imaging signal is output from the CCD 21 or may be performed on the imaging signal input from the CCD 21 by the DSP 52.

  Further, as shown in FIG. 16, after the surface blood vessel suppression image data 78 is refined, a color tone conversion process for converting to the same color tone as that of the special light image data 71 is performed, thereby changing the color tone of the surface blood vessel suppression image data 78. It may be corrected.

  Further, as shown in FIG. 17, a predetermined coefficient p is determined in advance according to the ratio of the light emission amounts of the blue LD 66 and the blue-violet LD 67, and a value obtained by multiplying the G signal by the coefficient p is set as the pixel value of the R pixel. Also, the color tone of the surface blood vessel suppression image data 78 can be corrected.

  The tone correction processing performed as described above is easily realized by preparing a plurality of tone conversion look-up tables (LUTs) in advance according to the degree of suppression or the like, and using them according to the degree of suppression. be able to. In addition, when performing color tone correction processing by calculation, a plurality of matrices (MTX) to be used for calculation may be prepared. The same applies to the case where the color tone of the mid-deep blood vessel suppression image data 74 is corrected by gain correction. The LUT for determining the gain according to the degree of suppression and the MTX used when calculating the gain according to the degree of suppression from the specified gain are used. It is enough to have more than one. The same applies when the predetermined coefficient p is used.

  In the second embodiment described above, the display of the superficial blood vessel 72 is suppressed by using the characteristics of the phosphor 43 to increase the light emission amount of the blue LD 66 relative to the blue-violet LD 67. The aspect which suppresses the display of the blood vessel 72 is not limited to this. Similar to the second embodiment described above, display suppression of the superficial blood vessel 72 can also be realized by other modes that adjust the components of the illumination light.

  For example, as shown in FIG. 18, the light source device 14 is provided with a blue-green LD 81 as a third laser diode used for suppressing display of the surface blood vessel 72. The blue-green LD 81 is a light source that emits a blue-green laser beam having a wavelength of 473 nm, and is combined by the coupler 69 similarly to the blue LD 66 and the blue-violet LD 67, and is irradiated from the light projecting unit 41 into the subject as illumination light. The blue-green laser light is diffused by the phosphor 43 and is uniformly irradiated in the field of view as blue-green illumination light. The blue-green LD 81 is lit when the display of the surface blood vessel 72 is suppressed, and is not lit during normal light observation or the like.

  As shown in FIG. 19, blue-green light (473 nm) has a relatively high reflectivity of the superficial blood vessel 72 when the reflectivity of the superficial blood vessel 72 and the mid-deep blood vessel 73 is compared, and light in other wavelength bands. Even when compared with the above, light having a wavelength with a large difference in reflectivity between the surface blood vessel 72 and the intermediate deep blood vessel 73 is obtained. For this reason, by adding blue-green light to the illumination light as described above, the contrast of the superficial blood vessel 72 is relatively lowered with respect to the mid-deep blood vessel 73, so that the display of the superficial blood vessel 72 can be suppressed. In addition, by using blue-green light, an image of the middle-deep blood vessel 73 can be taken with higher contrast compared to a case where this is not used.

  Here, an example of using blue-green light has been described. However, when suppressing the display of the surface blood vessel 72, light of other wavelengths is added as illumination light, and the contrast of the B signal is relatively reduced. The display of the superficial blood vessel 72 may be suppressed. For example, as shown in FIG. 20, when a xenon lamp 82 that emits white light is added as a third light source to suppress the display of the superficial blood vessel 72, the xenon lamp 82 is turned on and the normal light contained in the illumination light is included. By increasing the light component, the display of the superficial blood vessel 72 may be suppressed by relatively reducing the contrast of the B signal.

[Third Embodiment]
In addition, although the aspect which suppresses the display of the mid-deep blood vessel 73 was demonstrated in 1st Embodiment and the aspect which suppresses the display of the surface blood vessel 72 was demonstrated in 2nd Embodiment, respectively, these 2 types of display suppression functions are It is preferable that they are mounted on the same electronic endoscope system. Which of the superficial blood vessel 72 and the intermediate deep blood vessel 73 is to be observed differs depending on the medical condition and the like, and the electronic endoscope system depends on which of the superficial blood vessel 72 and the intermediate deep blood vessel 73 is to be observed This is because it is complicated and the burden on the subject is large.

  When the display suppression function of the middle-deep blood vessel 73 and the surface blood vessel 72 is mounted on one electronic endoscope, a suppression display processing unit 60 is provided in the DSP 52 like the electronic endoscope system 86 shown in FIG. And the light quantity ratio adjustment part 77 should just be provided in CPU68 of the light source device 14, and it should just make it function by setting.

  When the suppression display processing unit 60 and the light amount ratio adjustment unit 77 are provided in this way, as shown in the setting window 87 shown in FIG. It is preferable to use a setting GUI. The setting window 87 is displayed on the monitor 22 by operating the operation unit 56, and includes, for example, alternative check boxes 88a to 88c and suppression degree setting fields 89a and 89b.

  When suppressing the display of the superficial blood vessel 72, the check box 88a is checked in the setting window 87, and the suppression degree is set in the suppression degree setting field 89a. Thereby, the light quantity ratio adjustment part 77 operates, and the display of the superficial blood vessel 72 is suppressed according to the suppression degree set in the suppression degree setting column 89a.

  When suppressing the display of the middle-deep blood vessel 73, the check box 88b is checked in the setting window 87, and the suppression degree is set in the suppression degree setting field 89b. Thereby, the suppression display process part 60 act | operates and the display of the middle depth blood vessel 73 is suppressed according to the suppression degree set to the suppression degree setting column 89b.

  When neither the superficial blood vessel 72 nor the mid-deep blood vessel 73 is suppressed, the check box 88c is checked. As a result, the electronic endoscope system 86 does not operate the suppression display processing unit 60 and the light amount ratio adjustment unit 77, and the special light image data is used during the special light observation as described in the first embodiment and the second embodiment. 71 is generated.

  The aspect of the setting window 87 described above is an example, and the setting window 87 of another aspect may be used. For example, in the setting window 87, an example has been described in which numerical values are input to the suppression degree setting fields 89a and 89b. In addition, since the setting contents set in the setting window 87 are different for each doctor, it is stored individually for each doctor who uses the electronic endoscope system, and by inputting the ID of the doctor to be used, the previous use state Is preferably restored.

  Here, an example will be described in which one of the suppression display processing unit 60 and the light amount ratio adjustment unit 77 functions to suppress the display of either the mid-deep blood vessel 73 or the surface blood vessel 72. When suppressing the display of the defect 72, both the suppression display processing unit 60 and the light amount ratio adjusting unit 77 may be used at the same time. As described above, the suppression display processing unit 60 can suppress the display of the middle-layer blood vessel 73 and can suppress the display of the surface blood vessel 72 by adding the R signal or the G signal to the B signal. Because.

[Fourth Embodiment]
In the above-described first to third embodiments, by suppressing the display of blood vessels that are not the observation target among the surface blood vessels 72 and the middle-deep blood vessels 73 regardless of whether or not the frequency enhancement processing is performed by the DIP 53, Although the example of improving the visibility of the blood vessel to be observed has been described, the enhancement processing performed in the DIP 53 and the blood vessel suppression display processing described in the first to third embodiments may be linked. Hereinafter, as described in the third embodiment, it is assumed that one electronic endoscope system 86 is provided with both the suppression display processing unit 60 and the light amount ratio adjusting unit 77.

  In this case, for example, as shown in FIG. 23, using the setting window 91 for setting whether or not to perform the enhancement process, the enhancement process is performed on the surface blood vessel 72 or the enhancement process is performed on the mid-deep blood vessel 73. Select whether to apply emphasis processing to either. Checking the check boxes 92a to 92c for setting a blood vessel to be emphasized or not performing enhancement processing is an alternative. The emphasis degree setting columns 93a and 93b are columns for inputting how much the superficial blood vessel 72 and the intermediate deep blood vessel 73 are emphasized and displayed, for example, by a numerical value of 1-100.

  When the check box 92a is checked to emphasize the superficial blood vessel 72, the electronic endoscope system operates as follows. The check box 92a is a setting for emphasizing the superficial blood vessel 72, and does not select whether or not to suppress the mid-deep blood vessel 73. However, when the superficial blood vessel 72 is an observation target, the mid-deep blood vessel 73 superimposed on the superficial blood vessel 72 may interfere with the observation of the superficial blood vessel 72, so that the CPU 51 of the processor device 13 has the check box 92a checked. Then, the suppression display processing unit 60 of the DSP 52 is operated in conjunction with the setting of performing the frequency enhancement processing for emphasizing the superficial blood vessel 72. For this reason, the DSP 52 generates the mid-deep blood vessel suppression image data 74 by the suppression display processing unit 60 based on the imaging signals of the respective colors input from the CCD 21 and inputs them to the DIP 53.

  The DIP 53 performs frequency enhancement processing of a predetermined frequency for emphasizing the superficial blood vessel 72 on the input middle-deep blood vessel suppression image data 74. Therefore, as the observation image displayed on the monitor 22 is set to emphasize the superficial blood vessel 72 in the setting window 91, the superficial blood vessel 72 is emphasized by the frequency emphasis processing, and at the same time, the superficial blood vessel 72 is observed. The display of the middle-deep blood vessel 73 that can be hindered is automatically suppressed.

  Note that the DIP 53 enhances the image of the superficial blood vessel 72 to the extent corresponding to the enhancement degree input in the enhancement degree setting field 93a by the frequency enhancement process. On the other hand, the suppression display processing unit 60 sets the suppression degree to the suppression degree (for example, the same value as the enhancement degree) corresponding to the enhancement degree input in the enhancement degree setting field 93a when the intermediate deep blood vessel suppression image data 74 is generated. Automatically set, and based on this, the R signal addition rate is determined.

  Similarly, when the check box 92b is checked to emphasize the middle-deep blood vessel 73, the electronic endoscope system operates as follows. The check box 92b is used to make a setting for emphasizing the mid-deep blood vessel 73, and does not select whether or not to suppress the surface blood vessel 72. However, when the intermediate deep blood vessel 73 is an observation target, the superficial blood vessel 72 superimposed on the intermediate deep blood vessel 73 may interfere with the observation of the intermediate deep blood vessel 73, so the CPU 51 of the processor device 13 may check the check box 92 b. Is checked, and the light amount ratio adjusting unit 77 is operated in conjunction with the setting that the frequency enhancement processing for emphasizing the intermediate deep blood vessel 73 is performed. Accordingly, when emphasizing the middle-layer blood vessel 73, the light amount ratio adjusting unit 77 adjusts the ratio of the light emission amounts of the blue LD 66 and the blue-violet LD 67, thereby adjusting the components included in the illumination light and generating special light generated by the DSP 52. The image data 71 becomes surface blood vessel suppression image data 78.

  The DIP 53 performs frequency enhancement processing of a predetermined frequency for emphasizing the mid-deep blood vessel 73 on the surface blood vessel suppression image data 78 input from the DSP 52. Therefore, the observation image displayed on the monitor 22 is enhanced by the frequency enhancement process at the same time as the mid-depth blood vessel 73 is enhanced by the setting of emphasizing the mid-depth blood vessel 73 in the setting window 91. The display of the superficial blood vessels 72 that may hinder the observation of 73 is automatically suppressed.

  Note that the DIP 53 enhances the image of the mid-deep blood vessel 73 to the extent corresponding to the enhancement level input in the enhancement level setting field 93b by the frequency enhancement process. On the other hand, when the light amount ratio adjusting unit 77 adjusts the ratio of the light emission amounts of the blue LD 66 and the blue-violet LD 67, the degree of suppression corresponds to the degree of suppression (for example, enhancement) input to the enhancement level setting field 93b. The light emission amount ratio of the blue LD 66 and the blue-violet LD 67 is determined based on this.

  When the enhancement processing by the DIP 53 and the suppression display processing are performed in this way, the display of the fine structure that hinders the observation is automatically suppressed and displayed only by selecting the target to be observed. There is no need to set each separately, improving usability.

  In the above-described fourth embodiment, the example of suppressing the display of blood vessels that are not the observation target in conjunction with the setting for performing the enhancement processing has been described. However, in conjunction with the setting of the suppression display, the blood vessels that are not suppressed are observed. It may be regarded as a target and the emphasis process may be automatically performed.

  In the above-described fourth embodiment, the electronic endoscope system including both the suppression display processing unit 60 and the light amount ratio adjusting unit 77 has been described as an example. However, the electronic endoscope system 11 and the second embodiment of the first embodiment are described. Also in the case of the electronic endoscope system 76 of the embodiment, the setting of the enhancement process and the setting of the suppression display may be linked.

[Fifth Embodiment]
In the first to fourth embodiments described above, a so-called simultaneous electronic endoscope system that captures a color image has been described as an example, but the present invention is not limited thereto. For example, a so-called frame-sequential electronic endoscope system that uses a monochrome imaging device to sequentially capture a plurality of colors and synthesizes the images of the obtained colors to obtain a color photographed image is also known. However, the display of the superficial blood vessel 72 and the middle-deep blood vessel 73 can be suppressed even in the frame sequential electronic endoscope system. Hereinafter, although an example of a field sequential electronic endoscope will be described, the same members as those in the first to fourth embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  As shown in FIG. 24, the electronic endoscope system 101 includes a CCD 102 as an image pickup element in the electronic endoscope 12. The CCD 102 is a monochrome imaging element not provided with a color filter, and sequentially performs imaging for each color by switching the color of the illumination light irradiated in the subject.

  The DSP 52 generates one piece of image data based on a plurality of image pickup signals from the CCD 102. The DSP 52 generates normal light image data by combining all the RGB colors according to the setting, or combines, for example, a blue image photographed under blue illumination light and a green image photographed under green illumination light. Thus, image data (described later) corresponding to the special light image data 71 is generated.

  The DSP 52 includes a suppression display processing unit 103. The suppression display processing unit 103 generates image data in which the display of the surface blood vessels 72 is suppressed and image data in which the display of the middle-deep blood vessels 73 is suppressed based on a plurality of color imaging signals sequentially input from the CCD 102. The suppression display processing unit 103 functions when the display of the surface blood vessel 72 or the intermediate deep blood vessel 73 is suppressed.

  The light source device 104 includes a white light source 105 and a rotation filter 106. The white light source 105 is a light source that emits broadband white light such as a white LD, LED, or xenon lamp, and the timing and amount of light emission are adjusted by the CPU 68.

  The rotary filter 106 is a filter that is disposed in front of the white light source 105 and restricts the white light emitted from the white light source 105 to narrow band light having a predetermined wavelength so as to enter the electronic endoscope 12. The rotary filter 106 is divided into a plurality of sections as will be described later, and the wavelength of the narrowband light incident on the electronic endoscope 12 is different for each section. The rotary filter 106 is rotatably disposed on the front surface of the white light source 105, and is rotated at a predetermined timing under the control of the CPU 68. Thereby, the wavelength of the narrow-band light irradiated as illumination light in the subject is sequentially switched.

  Illumination light that has become narrow-band light by passing through the rotary filter 106 is guided to the light guide 42 through a lens (not shown) and the like, and a lens or illumination window provided at the distal end portion 20 of the electronic endoscope 12. It is irradiated into the subject through the like.

  As shown in FIG. 25, the rotary filter 106 includes three types of filters that transmit light in an extremely narrow wavelength band (hereinafter referred to as narrow band light). The blue narrow band filter 111 transmits blue narrow band light, the green narrow band filter 112 transmits green narrow band light, and the blue green narrow band filter 113 transmits blue green narrow band light. For example, blue narrowband light has a wavelength of 415 nm, green narrowband light has a wavelength of 540 nm, and blue-green narrowband light has a wavelength of 445 nm. Here, for the sake of simplicity, the rotary filter 106 is divided into three by a blue narrow band filter 111, a green narrow band filter 112, and a blue green narrow band filter 113, but a filter or a predetermined range that transmits other colors such as red. A filter that transmits light in the wavelength band, a filter that transmits / shields light of all colors, and the like may be provided. Further, the angle occupied by each filter may be arbitrarily determined in order to ensure the irradiation time necessary for each color.

  As shown in FIG. 26, in the case of performing special light observation, the electronic endoscope system 101 performs blue light based on a blue image pickup signal imaged under illumination of blue narrow band light transmitted through the blue narrow band filter 111 by the DSP 52. Image data 114 is generated. Further, green image data 115 is generated based on a green image pickup signal imaged under illumination of green narrowband light transmitted through the green narrowband filter 112. Then, the DSP 52 generates image data in which the blue image data 114 is assigned to the B pixel and the G pixel, and the green image data 115 is assigned to the R pixel. The image data generated in this way corresponds to the special light image data 71 in the first to fourth embodiments described above.

  When suppressing the display of the mid-deep blood vessel 73, the DSP 52, together with the blue image data 114 and the green image data 115, obtains the blue-green image data 116 based on the blue-green image signal captured under the illumination of the blue-green narrow band light. Generate. Then, the DSP 52 generates the mid-deep blood vessel suppression image data 117 by the suppression display processing unit 103.

  At this time, the suppression display processing unit 103 first generates first intermediate image data 121 obtained by adding the green image data 115 and the blue-green image data 116 for each pixel. The middle deep blood vessel 73 is displayed as the contrast of the green image data 115. On the other hand, blue-green narrow-band light (445 nm) is light having a wavelength with less difference in reflectance between the surface blood vessel 72 and the middle-deep blood vessel 73 and the mucous membrane compared to other wavelengths (see FIG. 19). For this reason, the contrast of the middle-deep blood vessel 73 and the surface blood vessel 72 projected in the blue-green image data 116 is low. Therefore, by adding the green image data 115 and the blue-green image data 116, in the first intermediate image data 121, the contrast of the middle deep blood vessel 73 is lowered with respect to the green image data 115.

  When the first intermediate image data 121 is generated, the addition of the green image data 115 and the blue-green image data 116 is performed by weighting according to a preset degree of suppression. For example, as the degree of suppression increases, the ratio of the blue-green image data 116 to the green image data 115 increases, and the contrast of the middle-deep blood vessel 73 is further reduced.

  The suppression display processing unit 103 uses the first intermediate image data 121 for the R pixel, combines the first intermediate image data 121 and the blue image data 114 using the blue image data 114 for the B pixel and the G pixel, Middle deep blood vessel suppression image data 117 is generated. Since the superficial blood vessel 72 is displayed as the contrast of the blue image data 114, the medium-deep blood vessel suppression image data 117 generated by the suppression display processing unit 103 also has the same contrast as the blue image data 114 as the B pixel and G pixel images. Observed. On the other hand, since the contrast of the intermediate deep blood vessel 73 is reduced at the stage when the first intermediate image data 121 is generated, the contrast is low in the intermediate deep blood vessel suppression image data 117 and the display is suppressed.

  When suppressing the display of the superficial blood vessel 72, the DSP 52 generates blue image data 114, green image data 115, and blue green image data 116. Further, the DSP 52 generates the surface blood vessel suppression image data 118 by the suppression display processing unit 103.

  When generating the surface blood vessel suppression image data 118, the suppression display processing unit 103 first generates the second intermediate image data 122 obtained by adding the blue image data 114 and the blue-green image data 116 for each pixel. The superficial blood vessel 72 is imaged as the contrast of the blue image data 114. On the other hand, as described above, the blue-green narrow band light has a wavelength with a small difference in reflectance between the surface blood vessel 72, the mid-depth blood vessel 73, and the mucous membrane, and therefore the contrast of the surface blood vessel 72 projected on the blue-green image data 116 is low. Therefore, by adding the blue image data 114 and the blue-green image data 116, the contrast of the surface blood vessel 72 is lowered with respect to the blue image data 114 in the second intermediate image data 122.

  Note that when the second intermediate image data 122 is generated, the addition of the blue image data 114 and the blue-green image data 116 is performed by weighting according to a preset degree of suppression. For example, as the set degree of suppression increases, the ratio of the blue-green image data 116 to the blue image data 114 increases, and the contrast of the surface blood vessel 72 is further reduced.

  The suppression display processing unit 103 combines the second intermediate image data 122 and the blue image data 114 by using the second intermediate image data 122 for the B pixel and the G pixel, and using the green image data 115 for the R pixel. Then, surface blood vessel suppression image data 118 is generated. Since the mid-deep blood vessel 73 is displayed as the contrast of the green image data 115, the surface blood vessel suppression image data 118 is also observed as an R pixel image with the same contrast as the green image data 115. On the other hand, since the contrast of the superficial blood vessel 72 is reduced when the second intermediate image data 122 is generated, the superficial blood vessel suppressed image data 118 also has a low contrast and is suppressed from being displayed.

  In the above-described fifth embodiment, the example in which the rotary filter 106 including the three filters of the blue narrow band filter 111, the green narrow band filter 112, and the blue green narrow band filter 113 is used has been described, but the present invention is not limited thereto.

  For example, as shown in FIG. 29, a rotary filter 123 having a blue narrow band filter 111 and a green narrow band filter 112 is provided in a replaceable manner together with the above-described rotary filter 106, and display of the surface blood vessels 72 and the middle deep blood vessels 73 is displayed. The rotation filter 106 may be used for suppressing the rotation, and the rotation filter 123 may be used for suppressing the display.

  In the above-described fifth embodiment, the example in which the three types of filters of the blue narrow band filter 111, the green narrow band filter 112, and the blue green narrow band filter 113 are used as the rotation filter 106 has been described. However, the present invention is not limited to this.

  For example, as shown in FIG. 30, rotary filters 123a to 123c having two types of filters, a blue narrow band filter and a green narrow band filter, are provided in a replaceable manner. The blue narrow-band filters (blue 1 to blue 3) of these rotary filters 123a to 123c are common in that they transmit blue narrow-band light, but have different wavelengths to transmit. For this reason, the contrast of the superficial blood vessel 72 projected on the blue image data 114 is different for each of the rotary filters 123a to 123c.

  Similarly, the green narrow band filters (green 1 to green 3) of the rotary filters 123a to 123c are common in that they transmit green narrow band light, but have different transmission wavelengths. For this reason, the contrast of the mid-deep blood vessel 73 projected on the green image data 115 differs among the rotary filters 123a to 123c.

  Therefore, by selecting which one of the surface blood vessels 72 and the middle-layer blood vessels 73 is to be suppressed and selecting an appropriate one from the rotation filters 123a to 123c according to the set degree of inhibition, the surface blood vessels are selected. 72 and image data in which the middle-layer blood vessel 73 is suppressed can be obtained. In this case, when the blue image data 114 and the green image data 115 photographed using the rotary filters 123a to 123c are combined as described with reference to FIG. 26, there is no display suppression depending on the used rotary filters 123a to 123c. Special light image data, mid-deep blood vessel suppression image data 117, and surface blood vessel suppression image data 118 can be obtained.

  In the electronic endoscope system 101 described in the fifth embodiment, the blue-green image data 116 is converted into the green image data 115 (or the blue image data 114) as in the first to fourth embodiments. As a result of the addition, the color tone of the generated mid-deep layer blood vessel suppression image data 117 (or surface layer blood vessel suppression image data 118) changes compared to the case where no blood vessel suppression display is performed. Therefore, as described in the first and second embodiments, it is preferable to correct the color tone of the generated image data 114 and 115 by gain correction or color tone conversion processing. Similarly, as described in the first and second embodiments, when the blue-green image data 116 and the green image data 115 (or the blue image data 114) are added, the pixel value finally obtained is The color tone may be adjusted by multiplying the blue-green image data 116 and the green image data 115 (or the blue image data 114) by a predetermined coefficient and adding them so as to be constant.

  In the above-described fifth embodiment, the example of suppressing the display of the surface blood vessel 72 or the intermediate deep blood vessel 73 has been described. However, as described in the fourth embodiment, the suppression display is performed in conjunction with the highlight display. Also good.

  In the above-described fifth embodiment, the blue-green narrow band filter 113 is provided, and the blue-green image data 116 obtained when the blue-green light is photographed as illumination light is added to the green image data 115 and the blue image data 114. Although the example which suppresses the display of the surface blood vessel 72 and the mid-deep blood vessel 73 was demonstrated by this, it is not restricted to this. For example, the image data to be added to the green image data 115 or the blue image data 114 for display suppression may be an image with a low contrast of the surface blood vessels 72 and the mid-deep blood vessels 73. For this reason, it is not always necessary to add the blue-green image data 116. For example, it is possible to add red image data obtained under illumination of red narrowband light or white light image data obtained under illumination of white light. good. In this case, necessary filters and openings may be provided in the rotary filter 106 in advance.

  In the first to fourth embodiments, the example in which the B signal output from the CCD 21 is assigned to the B signal and the G signal and the G signal is assigned to the R pixel to generate the image data has been described. The correspondence relationship between the imaging signal and the pixel of the image data to be generated is not limited to this example. Similarly, in the fifth embodiment, the example in which the image data is generated using the blue image data 114 for the B pixel and the G pixel and the green image data 115 for the R pixel has been described. However, the image data is generated with the image data of each color. The correspondence with the pixels of the image data is not limited to this example. For example, even when the B signal is assigned to the B pixel, the G signal is assigned to the G pixel, and the R signal is assigned to the R pixel, the display of the surface blood vessels 72 and the intermediate deep blood vessels 73 is performed in the same manner as in the first to fourth embodiments. Can be suppressed. The same applies to the field sequential electronic endoscope system 101 as in the fifth embodiment.

  In the first to fifth embodiments described above, the example in which the CCD is used as the image sensor has been described. However, an image sensor of another aspect such as a CMOS may be used. Further, the number and arrangement of image sensors to be used are arbitrary.

  In the first to fifth embodiments described above, an example has been described in which a suppression display processing unit is provided in the DSP 52, and image data in which display of blood vessels outside the observation target is suppressed by signal processing is generated. . For example, the DSP 52 generates image data for each color based on the imaging signal input from the CCD, and the DIP 53 performs image processing for synthesizing the image data of these colors, thereby performing the first to first described above. As in the fifth embodiment, an observation image that suppresses the display of blood vessels that are not the object of observation may be generated.

11, 76, 86, 101 Electronic endoscope system 12 Electronic endoscope 13 Processor device 14, 104 Light source device 16 Insertion portion 17 Operation portion 18 Connector 19 Universal code 20 Tip portion 21, 102 CCD
22 Monitor 31 Objective optical system 32 TG
33 AFE
34, 51, 68 CPU
36 Observation Window 41 Projecting Unit 42 Light Guide 43 Phosphor 52 DSP
53 DIP
54 Display control circuit 56 Operation unit 57 ROM
58 RAM
60,103 Suppression display processing unit 59 VRAM
66 Blue LD
67 Blue-violet LD
69 Coupler 71 Special light image data 72 Surface blood vessel 73 Middle deep blood vessel 74 Medium deep blood vessel suppression image data 77 Light intensity ratio adjustment unit 78 Surface blood vessel suppression image data 81 Blue green LD
82 Xenon lamp 87, 91 Setting window 88a-88c, 92a-92c Check box 89a, 89b Suppression setting column 93a, 93b Enhancement setting column 105 White light source 106, 123 Rotation filter 111 Blue narrow band filter 112 Green narrow band filter 113 Blue-green narrowband filter 114 Blue image data 115 Green image data 116 Blue-green image data 117 Medium-deep blood vessel suppression image data 118 Surface blood vessel suppression image data 121 First intermediate image data 122 Second intermediate image data

Claims (9)

Illumination light irradiating means having a plurality of narrow band filters that transmit white light limited to narrow band light, and sequentially irradiating a plurality of colors of illumination light to a living tissue in a body cavity;
Imaging means for imaging the living tissue for each color under the illumination light of the plurality of colors, and outputting a color signal of each color as an imaging signal;
Display image generating means for generating a display image based on an imaging signal output by the imaging means;
Reduce the contrast of the non-observation target blood vessel by adding another color signal with low contrast of the non-observation target blood vessel to the color signal with high contrast of the non-observation target blood vessel among the surface layer blood vessels and the middle-layer blood vessels. Suppressing means for suppressing the display of the non-observation target blood vessels with respect to the observation target blood vessels,
An electronic endoscope system comprising: The suppression means changes an addition ratio according to a preset parameter when adding a color signal having a low contrast of the non-observation target tissue to a color signal having a high contrast of the non-observation target blood vessel. The electronic endoscope system according to claim 1 , wherein the degree of suppressing display of the non-observation target blood vessel is changed. As the narrowband filter, a first narrowband filter for obtaining a color signal with a high contrast of the surface blood vessel, a second narrowband filter for obtaining a color signal with a high contrast of the mid-depth blood vessel, and the surface blood vessel The electronic endoscope system according to claim 1, further comprising: a third narrow band filter for obtaining a color signal having a low contrast between the middle-deep blood vessels. When the blood vessel to be observed is the middle-deep blood vessel and the blood vessel to be unobserved is a surface blood vessel,
The suppression means transmits the first color signal obtained from the first illumination light that is transmitted through the first narrowband filter and is irradiated through the third narrowband filter. Generating an intermediate signal generated by adding the third color signal obtained under the light;
The display image is obtained by using the intermediate signal and the second color signal obtained under the second illumination light irradiated through the second narrowband filter for each pixel. The electronic endoscope system according to claim 3 , wherein the electronic endoscope system is generated. When the observation target blood vessel is the surface blood vessel, and the non-observation target blood vessel is a mid-deep blood vessel,
The suppressing means transmits the second color signal obtained based on the second illumination light transmitted through the second narrowband filter and transmitted through the third narrowband filter. Generating an intermediate signal generated by adding the third color signal obtained under the light;
The display image uses the intermediate signal and the first color signal obtained under the first illumination light irradiated through the first narrow band filter for each pixel. The electronic endoscope system according to claim 3, wherein the electronic endoscope system is generated. The electronic endoscope system according to any one of claims 1 to 5 , further comprising an enhancement processing unit that performs an enhancement process to enhance the blood vessel to be observed on the display image. The suppressing means, according to claim 6, characterized in that in conjunction with the vessel of emphasizing the observation target is selected by the enhancement processing unit by setting, to suppress the display of the non-observation target vessel Electronic endoscope system. The display image generation unit generates the display image by using the blue imaging signal for a blue pixel and a green pixel and using the green imaging signal for a red pixel . 7 electronic endoscope system according to any one of. The electronic endoscope system according to claim 1 , further comprising a color tone correction unit that corrects a color tone of the display image.

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