JP2012217483A - Endoscope system, and driving method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope system by which a load on a patient can be reduced by continuing observation even when any one of multiple light sources is turned off due to a failure or the like.SOLUTION: The endoscope system includes a control means 31 for substituting the illumination light of the normal light source among the light sources for the light source with a failure when any one of the multiple light sources 33a, 33b, 35a, 35b is turned off due to a failure, and also for changing over the image processing 37 of a picked up image signal output from a solid state imaging element incorporated in the distal end part of an electronic endoscope, when the illumination light of the light source with a failure in a normal case is different from the illumination light of the light source for the substitution, thereby to restrict the change of a shade in a picked up image after the image processing between the shades before and after the substitution.

Description

  The present invention relates to an endoscope system capable of performing special light observation using broadband light such as white illumination light and specific narrow-band light, and a driving method thereof, and more particularly, a plurality of light sources prepared for a plurality of lamps. The present invention relates to an endoscope system that copes with a case where any one of the light sources is turned off, and a driving method thereof.

  The endoscope system includes an electronic endoscope (scope) having an insertion portion that is inserted into a body cavity, and a main body device to which the electronic endoscope is detachably connected.

  The main device includes a processor device and a light source device. The processor device receives an imaging signal output from an imaging sensor (solid-state imaging device) built in the distal end of the insertion portion of the electronic endoscope, performs image processing, and displays the obtained observation image on a monitor. The light source device generates light that illuminates the inside of the body cavity through a light guide inserted into the electronic endoscope.

  In recent years, an endoscopic system that can perform so-called special light observation that irradiates a specific mucosal tissue of a living body with specific narrow wavelength band light (narrowband light) and obtains tissue information at a desired depth of the living tissue has been utilized. Has been. This type of endoscope system can easily visualize biological information that cannot be obtained by a normal observation image, such as a superficial fine structure of a new blood vessel generated in a mucosa layer or a submucosa layer, and emphasis on a lesioned part.

  For example, when the object to be observed is a cancerous lesion, if the mucosal tissue is irradiated with blue (B) narrow-band light, the state of the fine blood vessels and microstructures on the tissue surface layer can be observed in more detail, so that the lesion can be identified more accurately. Can be diagnosed.

  The depth of light in the depth direction with respect to a living tissue depends on the wavelength of light. Blue (B) light with a short wavelength mainly reaches the surface layer due to absorption and scattering characteristics in living tissue, and is absorbed and scattered in the depth range up to that point. Can be observed.

  In the case of green (G) light, which has a longer wavelength than B light, it reaches deeper than the range where B light deepens and absorbs and scatters within that range, so information on the middle layer structure and surface layer structure is mainly observed. Can do.

  Red (R) light having a wavelength longer than that of G light reaches a deeper tissue and is absorbed and scattered in that range, so that information on the deep tissue and intermediate tissue can be mainly observed.

  That is, image signals obtained by receiving each return light obtained by irradiating B light, G light, and R light by an image sensor such as a CCD type or a CMOS type are mainly information on the surface layer structure, mainly the middle layer. It is known to include information on tissues and superficial tissues, and mainly information on deep tissues and intermediate tissues.

  For this reason, in special light observation, in order to make it easy to observe the fine blood vessels and fine structures on the tissue surface layer in the living tissue, the narrow band light of blue (B) suitable for observation of the surface layer tissue, and the middle layer tissue and Only two types of narrow band light of green (G) suitable for observation of the surface layer tissue are used, and red (R) narrow band light mainly suitable for observation of the middle layer and deep layer tissue of the living tissue is rarely used. I can't.

  A B image signal (B narrowband data) mainly including information on the surface layer tissue obtained by the imaging sensor, and a G image signal (G narrowband data) mainly including information on the middle layer tissue and the surface layer tissue obtained by the imaging sensor. Is used to perform image processing, display a pseudo color image on a monitor, and observe a subject.

  In special light observation when red (R) light is not used as illumination light, a color image is obtained by multiplying a G image signal (G narrowband data) obtained by an image sensor by a predetermined coefficient in image processing of the captured image signal. Are assigned as R image data, B image signals (B narrowband data) are multiplied by different predetermined coefficients and assigned to G image data and B image data of a color image, respectively, and pseudo color images made up of RGB 3ch (channel) color image data Is generated and displayed on the monitor.

  That is, in the image processing in the narrow band light mode, the two color image signals of the G image signal and the B image signal by the narrow band light are converted into RGB three color image data and displayed on the monitor as a pseudo color image. Image processing in white light (normal light) mode (image processing for converting three color R image signals, G image signals, and B image signals obtained by receiving light with an image sensor into RGB color image data for color display) Is different.

  In special light observation using not only G narrowband light and B narrowband light but also R narrowband light, when the purpose is to observe microvessels and microstructures in the surface tissue, an R image signal (R narrowband light) As described above, the image processing is performed using only the G image signal and the B image signal, and the pseudo color image is displayed on the monitor for observation.

  Also in this case, in the image processing, the G image signal is allocated to the R image data, the B image signal is allocated to the G image data and the B image data, and a pseudo color image including 3ch color image data is generated in the same manner as described above. It is displayed on the monitor.

  As a result, the pseudo-color image displayed on the monitor mainly includes a large amount of B image signals (B narrowband data) including information on the surface layer tissue, so that the state of the microvessels and microstructures of the surface layer tissue is more detailed. It becomes expressed and it becomes easy to observe the fine blood vessel and the fine structure of the surface layer tissue (see Patent Document 1 and Patent Document 2).

  In the endoscope system as described above, special light is emitted in the light source device, and this is irradiated to the observation object from the tip of the electronic endoscope through the light guide. There is a possibility that the light source is turned off due to a failure or the like while being inserted into the inside. In order to cope with this emergency situation, conventionally, as described in Patent Document 3 below, for example, when an abnormality occurs in the special light emission light source during special light observation, the normal light (pseudo-light) is automatically generated. Switching to observation with white light).

Japanese Patent No. 3559755 Japanese Patent No. 3607857 JP 2005-204910 A

  In an endoscope system that performs special light observation, in addition to using a plurality of light sources having different emission wavelengths, a light source that emits illumination light having the same wavelength is usually provided with a main light and a spare light in preparation for failure.

  If any light source goes out due to a failure while using the endoscope system, the observation is interrupted, the electronic endoscope is removed from the patient's body cavity, and the failed light source is replaced with a normal product, and then the Performing a mirror examination increases the burden on the patient.

  In particular, when a laser light source is used, a person who has qualifications for handling laser equipment must bring the light source device into a dedicated facility and replace the failed light source. Therefore, doctors and staff in the hospital where the endoscope system is installed. There is a restriction that the laser light source cannot be replaced without permission.

  For this reason, even if one of the light sources is extinguished due to a failure during the examination by the endoscope, it is preferable to continue observation using another lamp as much as possible to reduce the burden on the patient.

  However, observation may not be continued depending on the number and type of failed light sources, and the color of the observation image changes if the emission wavelength or light quantity of the light source to be substituted for the failed light source varies compared to before the failure. There is also a problem that it ends up.

  An object of the present invention is to provide an endoscope system and a driving method thereof that can reduce the burden on the patient by continuing observation even if any of the light sources is turned off due to a failure or the like.

  An endoscope system and a driving method thereof according to the present invention include an electronic endoscope in which a solid-state imaging device that irradiates illumination light to a subject from a tip portion and receives light from the subject is mounted on the tip portion; An endoscope system including a plurality of light sources, a light source device that introduces emitted light of the light sources into the electronic endoscope, and irradiates the subject with the emitted light as the illumination light, and driving thereof In the method, when any one of the plurality of light sources is extinguished due to a failure, the illumination light of a normal light source out of the light sources is substituted for the failure light source and the failure occurs. When the illumination light when the light source is normal differs from the illumination light of the substituted light source, the captured image after the image processing before and after the substitution is switched by switching the image processing of the captured image signal output from the solid-state imaging device. Color Which comprises suppressing the change.

  According to the present invention, even if any one of a plurality of light sources is turned off due to failure or deterioration, it is possible to continue observation while suppressing a change in color of the observation image, and to reduce the burden on the patient. .

1 is an overall configuration diagram of an endoscope system according to an embodiment of the present invention. It is a functional block diagram of the endoscope system concerning one embodiment of the present invention. 2 is a graph showing emission spectra of narrow-band light emitted from a narrow-band laser light source used as a light source of the endoscope system shown in FIG. 2 and pseudo-white light emitted from a white light source composed of a blue laser light source and a phosphor. It is. It is a block diagram which shows each signal processing system of the image processing of the endoscope system shown in FIG. (A) And (b) is a graph which shows one Example of the relationship between the emitted light amount from blue-violet laser light source (405LD) and blue laser light source (445LD) shown in FIG. 4, respectively, and elapsed time, respectively. It is a figure which shows an example of the color conversion table with which the special light color conversion part of the special light image process part shown in FIG. 4 is provided. It is a flowchart which shows the process sequence of the special light observation implemented with the endoscope system shown in FIG. It is a flowchart which shows the process sequence of the light quantity adjustment implemented with the endoscope system shown in FIG. It is explanatory drawing of the failure detection circuit of a laser light source. It is a figure which illustrates the observation mode restriction | limiting with respect to the failure pattern of the light source which concerns on embodiment of this invention. It is a figure which shows an example of the warning display displayed on a monitor when a failure generate | occur | produces in a light source. It is a figure which shows the other example of the warning display displayed on a monitor when a failure generate | occur | produces in a light source.

  Hereinafter, an endoscope system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an external view showing the overall configuration of an endoscope system according to an embodiment of the present invention, and FIG. 2 is a block diagram showing its schematic function. The endoscope system 10 of the present embodiment includes an electronic endoscope 12, a processor device 14 and a light source device 16 that constitute a main body device. The electronic endoscope 12 includes a flexible insertion portion 20 that is inserted into a body cavity of a patient (subject), an operation portion 22 that is connected to a proximal end portion of the insertion portion 20, a processor device 14, and a light source. And a universal cord 24 connected to the device 16.

  A distal end portion 26 is continuously provided at the distal end of the insertion portion 20, and an imaging element (CCD type or CMOS type solid-state imaging element: see FIG. 2) 21 for imaging in a body cavity and details will be described later. A phosphor 23 is incorporated. Behind the distal end portion 26 is provided a bending portion 28 in which a plurality of bending pieces are connected. When the angle knob 30 provided in the operation section 22 is operated, the bending section 28 is bent / moved in the vertical and horizontal directions by pushing / pulling the wire inserted in the insertion section 20. Thereby, the front-end | tip part 26 is orientated in the desired direction within a body cavity.

  A connector 36 is provided at the base end of the universal cord 24. The connector 36 is of a composite type and is connected to the light source device 16 in addition to being connected to the processor device 14.

  The processor device 14 supplies power to the electronic endoscope 12 through a cable inserted into the universal cord 24, controls the driving of the image pickup device 21, and picks up an image transmitted from the image pickup device 21 through the cable 29. A signal is received, and various received signal processing is performed on the received imaging signal to convert it into image data.

  The image data converted by the processor device 14 is displayed as an endoscopic image (observation image) on a monitor 38 connected to the processor device 14 by a cable. The processor device 14 is also electrically connected to the light source device 16 via the connector 36.

  In the processor device 14, a CPU (central processing unit) 31 that controls the entire endoscope system 10 is provided. The CPU 31 controls each component in the processor device 14. Drive control of each light source control part in the light source device 16 and the image sensor 21 in the electronic endoscope 12 is performed.

  In addition to an input / output unit provided in the operation unit 22 and the like, the processor device 14 is connected to a hard disk 42 (see FIG. 4) that records observation image data and the like. The input / output unit includes a mode switching unit 40 that performs mode switching such as a normal observation mode (also referred to as a normal light mode) and a special light observation mode (also referred to as a special light mode).

  At the distal end portion of the electronic endoscope 12, an illumination window 25 for irradiating the observation region with white illumination light or special light and a light receiving window 27 are provided, and the phosphor 23 is built inside the illumination window 25. In addition, the image sensor 21 is provided inside the light receiving window 27. A plurality of light receiving elements (photodiodes: pixels) (not shown) are arranged in a two-dimensional array on the light receiving surface of the image pickup element 21, and RGB color filters are stacked in a Bayer array, for example, on each light receiving element. Yes. The color filter may be a complementary color system.

  A cover glass and a lens constituting the illumination optical system are arranged inside the illumination window 25, and an objective lens unit constituting the imaging optical system is arranged inside the light receiving window 27, but these are not shown. To do.

  The light source device 16 includes a blue-violet laser light source (405LD) 33a and 33b having a center wavelength of 405 nm used as a special light source in the special light mode, and a white illumination light source used in both the normal light mode and the special light mode. And blue laser light sources (445LD) 35a and 35b having a central wavelength of 445 nm used as the light source.

  The blue-violet laser light source 33a and the blue laser light source 35a are used as main lights of the respective wavelengths, and the blue-violet laser light source 33b and the blue laser light source 35b are used as spare lights. Although the main lamp may be mainly used and the spare lamp may be used as a backup for the failure of the main lamp, in the present embodiment, the main lamp and the spare lamp are used simultaneously in parallel. When used in parallel, it is possible to reduce the amount of energization that flows in order to secure the amount of illumination light, to prolong the life of the light source, and to provide a bright light source because of simultaneous parallel use. The blue-violet laser light source may not be provided with the spare lamp 33b, but in the present embodiment, an example in which the spare lamp 33b is provided will be described.

  The blue-violet laser light having a center wavelength of 405 nm from the blue-violet laser light sources 33a and 33b is preferably a narrow-band light having a narrowed wavelength bandwidth that is preferably matched and narrowed according to the spectral characteristics of the structure and components of the living body. Therefore, the ability to detect the structure and components of the living body is excellent.

  Light emission from the semiconductor light emitting elements of the light sources 33a, 33b, 35a, and 35b is individually controlled by the light source control unit 48 (see FIG. 4), and the light emission conditions of the light sources 33a, 33b, 35a, and 35b, that is, The light quantity ratio between the emitted light from the blue-violet laser light sources 33a and 33b and the emitted light from the blue laser light sources 35a and 35b is freely changeable.

  As the blue-violet laser light sources 33a and 33b and the blue laser light sources 35a and 35b, a broad area type InGaN laser diode can be used, and an InGaNAs laser diode or a GaNAs laser diode can also be used. In addition, a light-emitting body such as a light-emitting diode may be used as the light source.

  Laser light emitted from each of the light sources 33a, 33b, 35a, and 35b is input to the light guide 39 by a condenser lens (not shown), and is input to the connector 36 via a multiplexer (not shown). Is transmitted. A configuration in which each laser beam from each light source 33 a, 33 b, 35 a, 35 b is directly sent to the connector 36 without using a multiplexer is also possible.

  The laser beam transmitted to the connector 36 by combining the blue-violet laser beam having the center wavelength of 405 nm and the blue laser beam having the center wavelength of 445 nm is transmitted to the tip of the electronic endoscope 12 by the light guide 39 constituting the illumination optical system. It is propagated to the part. Then, the blue laser light excites the phosphor 23 which is a wavelength conversion member disposed between the light emitting end of the light guide 39 and the illumination window 25 at the tip of the electronic endoscope 12 to emit fluorescence. . Some of the blue laser light passes through the phosphor 23 as it is.

  On the other hand, some of the blue-violet laser light excites the phosphor 23, but most of the blue-violet laser light is transmitted without exciting the phosphor 23 to become illumination light with a narrow band wavelength (so-called narrow band light).

  The combined laser light is demultiplexed into a plurality of systems, for example, two systems by a demultiplexer, and the laser light of each system is propagated to the distal end portion of the electronic endoscope 12 through separate light guides. It can also be set as the structure irradiated to a to-be-photographed object via each fluorescent substance from the illumination window provided in two places on either side.

  The light guide 39 is a multimode fiber. For example, a thin fiber cable having a core diameter of 105 μm, a cladding diameter of 125 μm, and a diameter of φ0.3 to 0.5 mm including a protective layer serving as an outer skin can be used.

The phosphor 23 absorbs a part of the blue laser light and the blue-violet laser light and emits green to yellow excitation light (for example, YAG phosphor or BAM (BaMgAl ₁₀ O ₁₇ )). Phosphor). As a result, green to yellow excitation light using blue laser light and blue-violet laser light as excitation light and blue laser light and blue-violet laser light transmitted without being absorbed by the phosphor 23 are combined to produce white (pseudo). White) illumination light.

  By using a semiconductor light emitting element that emits blue laser light with a central wavelength of 445 nm as an excitation light source as in this embodiment, high intensity white light can be obtained with high luminous efficiency, and the intensity of white light can be easily adjusted. In addition, changes in the color temperature and chromaticity of white light can be kept small.

  The phosphor 23 described above can prevent the occurrence of flickering when performing moving image display due to speckles caused by the coherence of the laser light, which may cause noise superimposition. In addition, the phosphor 23 takes into consideration the refractive index difference between the phosphor constituting the phosphor and the fixing / solidifying resin serving as the filler, and the particle size relative to the phosphor itself and the filler is changed to light in the infrared region. In contrast, it is preferable to use a material that has low absorption and high scattering. This enhances the scattering effect without reducing the light intensity for red or infrared light, and reduces the optical loss.

  FIG. 3 is a graph showing the blue-violet laser light from the blue-violet laser light sources 33a and 33b and the emission spectrum obtained by converting the wavelength of the blue laser light and the blue laser light from the blue laser light sources 35a and 35b by the phosphor 23. is there.

  Blue-violet laser light is narrow-band light represented by an emission line (profile A) having a center wavelength of 405 nm, and is mainly used for special light observation. The blue laser light is represented by a bright line having a center wavelength of 445 nm, and the excitation light emitted from the phosphor 23 by the blue laser light has a spectral intensity distribution in which the emission intensity increases in a wavelength band of approximately 450 nm to 700 nm.

  The above-described pseudo white light is formed by the profile B of the excitation light and the blue laser light, and is mainly the normal light. Although not shown, the phosphor 23 is also excited by blue-violet laser light and emits excitation light of about 1/8 the amount of light emitted by blue laser light to form pseudo white light.

  Here, the blue-violet laser light having a central wavelength of 405 nm and the accompanying excitation light emitted from the phosphor 23 emitted from the blue-violet laser light sources 33a and 33b have many components of narrow band light of 405 nm, and observation of the surface layer structure ( While it is excellent in (acquisition of surface layer information), the amount of the emitted white light used for background imaging cannot be increased because the component of the excitation light emitted from the phosphor 23 is small.

  For this reason, when the distance to the subject is short, the amount of emitted white light as a background is sufficient, but when the distance to the subject is long, the excitation light emitted by the blue-violet laser light emits white light. Insufficient light.

  In addition, the blue laser light having a central wavelength of 445 nm and the excitation light emitted from the phosphor 23 accompanying the blue laser light emitted from the blue laser light sources 35a and 35b are inferior to the observation of the surface layer structure as compared with the blue-violet laser light. 23 is strongly excited, and the amount of emitted white light as a background can be increased.

  For this reason, the blue laser light sources 35a and 35b can secure a sufficient amount of white light even when the distance to the subject is large, and the blue light from the blue-violet laser light sources 33a and 33b can cause a shortage of white light. Can be supplemented.

  Here, the white light referred to in the present embodiment is not limited to one that strictly includes all wavelength components of visible light. For example, the above-described pseudo white light, R, G, B, and the like can be specified. Any light may be used as long as it includes light in the wavelength band. For example, light including a wavelength component from green to red, light including a wavelength component from blue to green, and the like are included in a broad sense.

  In the endoscope system 10, the light intensity of the profile A and the profile B can be relatively increased and decreased by the light source control unit 48 to generate illumination light having an arbitrary luminance balance. In the endoscope system 10 of the present embodiment, only the light of profile B is used in the normal light mode, and in the special light mode, in principle, excitation light emission (not shown) based on the light of profile A and the light of profile A is used. Is used, and the light of the profile B is superimposed in order to compensate for the insufficient light amount of the excitation light emission (not shown).

  As described above, illumination composed of narrow-band light (profile A) by blue-violet laser light from blue-violet laser light sources (hereinafter referred to as 405LD) 33a and 33b and white light by excitation light emitted from the phosphor 23 (not shown). The illumination light (profile B) consisting of the light and the blue laser light from the blue laser light source (hereinafter referred to as 445LD) 35 a and 35 b and the white light by the excitation light emitted from the phosphor 23 is the tip of the electronic endoscope 12. The illumination window 25 irradiates the area to be observed of the subject.

  Then, the return light from the observation region irradiated with the illumination light is imaged on the light receiving surface of the imaging device 21 through the light receiving window 27, and the observation region is imaged by the imaging device 21. An image signal of a captured image output from the image sensor 21 after imaging is input to the image processing system 37 (FIG. 2) of the processor device 14 through the scope cable 29.

  The picked-up image signal picked up by the image pickup device 21 is subjected to image processing by a signal processing system including the image processing system 37 of the processor device 14, and is output to the monitor 38 and the recording device 42 for observation by the user.

  FIG. 4 is a configuration diagram of a signal processing system that performs image processing of the endoscope system 10 according to the present embodiment. As shown in the figure, the signal processing system of the endoscope system 10 includes a signal processing system of the electronic endoscope 12, a signal processing system of the light source device 16, and a signal processing system of the processor device 14 (the image in FIG. 2). A processing system 37), a monitor 38 and a recording device 42 are connected to the processor device 14, and a mode switching unit 40 is connected to the processor device 14 and the light source device 16.

  The signal processing system of the electronic endoscope 12 is a CDS / AGC circuit 44 for performing correlated double sampling (CDS) processing and automatic gain control (AGC) processing on an analog captured image signal output from the image sensor 21. And an A / D converter 46 for converting the analog image signal subjected to sampling and gain control by the CDS / AGC circuit 44 into a digital image signal. The captured image signal converted into the digital signal is input to the image processing system 37 of the processor device 14 via the connector 36.

  The signal processing system of the light source device 16 includes a light source controller 48 that performs on / off control and light amount control of the blue-violet laser light sources (405LD) 33a and 33b and the blue laser light sources (445LD) 35a and 35b.

  Here, the light source control unit 48 turns on the blue-violet laser light sources 33a and 33b in response to the light source ON signal accompanying the start of operation of the endoscope system 10, and the special light mode and the normal light mode from the mode switching unit 40. On / off control of the blue-violet laser light sources 33a, 33b is performed according to the switching signal, and the blue-violet laser light sources 33a, 33b and the blue laser light source are controlled according to the luminance value of the image calculated from the light amount calculation unit 50 described later. The light emission intensities of 35a and 35b, that is, the current values flowing through the light sources 33a and 33b and the light sources 35a and 35b are controlled.

  That is, the light source control unit 48, together with a light amount calculation unit 50 and a light amount ratio calculation unit 56, which will be described later, based on the calculated emission light amount and the ratio of the emitted light amount, the light emission conditions of the light sources 33a and 33b and the light sources 35a and 35b, It functions as a light quantity ratio changing means for changing the light quantity ratio.

  The signal processing system of the processor device 14 is constituted by an image processing system 37 (see FIG. 2). The image processing system 37 includes a light amount calculation unit 50, a DSP (digital signal processor) 52, a noise removal circuit 54, a light amount ratio calculation unit 56, an image processing switching unit (switch) 60, and a normal light image processing unit. 62, a special light image processing unit 64, and an image display signal generation unit 66.

  The light amount calculation unit 50 uses the digital image signal input from the A / D converter 46 of the endoscope 12 via the connector, and the light amount of the return light received by the image sensor 21, that is, the luminance value of the captured image. Is calculated. These calculated light quantities are output to the light source controller 48 and the light quantity ratio calculator 56.

  In the light source control unit 48, when the calculated light amount is less than a predetermined value, the blue-violet laser light sources (405LD) 33a and 33b and the blue laser light source (445LD) are set so that the light amount of the return light is not less than the predetermined value. The amount of light emitted from 35a and 35b is controlled. Hereinafter, the light sources 33a and 33b for the main light and the spare light are collectively referred to as the light source 33, and the light sources 35a and 35b for the main light and the spare light are collectively referred to as the light source 35.

  In the control of the emitted light quantity, first, the position of the endoscope tip and the subject is fixed, the blue laser light source (445LD) 35 is stopped, and the emitted light quantity of the blue-violet laser light source (405LD) 33 is increased (FIG. 5 ( a)). If the calculated return light quantity is equal to or greater than a predetermined value, the subject is imaged with the emitted light quantity. If the amount of light emitted from the blue-violet laser light source (405LD) 33 is maximum and the amount of return light is still insufficient, the blue laser light source (445LD) 35 is turned on as shown in FIG. When the total amount of emitted light is increased and the calculated amount of return light exceeds a predetermined value, the subject is imaged with the amount of emitted light.

  Generally, the amount of light emitted from the blue-violet laser light source (405LD) 33, which is a narrow-band light source, is not so large, and even when the amount of light emitted from the blue-violet laser light source (405LD) 33 is maximized, the amount of emitted light is limited. When the endoscope moves away from the subject, the amount of return light detected on the image sensor side becomes insufficient.

  Increasing the amount of light emitted by the blue laser light source (445LD) 35 to compensate for this shortage of light quantity will suffice, but the color tone of the picked-up image will change, and of course, the picked-up image related to the fine structure of the superficial blood vessels observed with special light The information will not stand out. For this reason, it is necessary to appropriately perform necessary image processing in the image processing system 37.

  In addition, in order to obtain the amount of return light necessary for imaging, the position of the endoscope tip and the subject are fixed and the amount of emitted light is controlled as described above. The position of the tip may be moved. For example, the emission light amount of the blue-violet laser light source (405LD) 33 is fixed at a predetermined value, the endoscope is moved, and the position of the endoscope tip and the subject so that the light amount of the return light becomes equal to or greater than the predetermined value. May be adjusted.

  Of course, when imaging is performed at a position where it is known in advance that the amount of light is insufficient with only the blue-violet laser light source (405LD) 33, the amount of light emitted from the blue-violet laser light source (405LD) 33 is maximized in advance, and the blue laser light source (445LD) ) Even if the output light quantity of 35 is fixed at a predetermined value and the endoscope is moved and the position of the endoscope tip and the subject is adjusted so that the light quantity of the return light is equal to or greater than the predetermined value, as described above. Good.

  The light amount ratio calculation unit 56 receives information on the current values of the currents that drive the blue-violet laser light source (405LD) 33 and the blue laser light source (445LD) 35 by the light source control unit 48, and calculates the light amount ratio of the emitted light amounts of the 405LD33 and 445LD35. calculate. The calculated light quantity ratio is output to a special light color conversion unit 74 described later of the special light image processing unit 64.

  Note that when the light quantity ratio of the laser changes, the white balance of the captured image changes. Therefore, although not shown, the light amounts and the light amount ratios of 405LD33 and 445LD35 are output to the CDS / AGC circuit 44, and the gain of the CDS / AGC circuit 44 for white balance based on the information on the light amount and the light amount ratio is provided. The signal processing system may be configured so that the electrical gain of the image sensor 21 is changed. Although not shown, the gain information for determining the white balance is output to the image processing unit 62 and the special light image processing unit 64 and used for color conversion and special light color conversion.

  The DSP 52 (digital signal processor) performs gamma correction and color correction processing on the digital image signal output from the A / D converter 46 after the light source light amount is detected by the light amount calculation unit 50. The noise removal circuit 54 removes noise from a digital image signal that has been subjected to gamma correction and color correction processing by the DSP 52 by performing a noise removal method in image processing such as a moving average method and a median filter method. Thus, the digital image signal input from the electronic endoscope 12 to the processor device 14 is subjected to preprocessing such as gamma correction, color correction processing, and noise removal by the DSP 52 and the noise removal circuit 54.

  The image processing switching unit 60 is configured by a switch, and sends the preprocessed digital image signal to the subsequent normal light image processing unit 62 based on an instruction (switching signal) from the mode switching unit (input unit) 40, or To switch to the special light image processing unit 64. In the present embodiment, the digital image signal before image processing by the normal light image processing unit 62 and the special light image processing unit 64 is referred to as an image signal, and the digital image signal before and after the image processing is referred to as image data.

  The normal light image processing unit 62 performs image processing for normal light suitable for the preprocessed digital image signal by the white light (profile B) by the 445LD and the phosphor 23 in the normal light mode. 68, a color enhancement unit 70, and a structure enhancement unit 72.

  The color conversion unit 68 performs color conversion processing such as 3 × 3 matrix processing, gradation conversion processing, and three-dimensional LUT processing on the preprocessed RGB 3 channel digital image signal, and converts the color converted RGB image data into Convert.

  The color emphasizing unit 70 is for emphasizing the blood vessels so that the blood vessels are easy to see by adding a color difference between the blood vessels and the mucous membranes in the screen. For example, a process of looking at an average color tone of the entire screen and emphasizing the color tone in a direction of adding a color difference between the blood vessel and the mucous membrane from the average value is performed.

  The structure enhancement unit 72 performs structure enhancement processing such as sharpness and contour enhancement on the color enhancement processed RGB image data.

  The RGB image data subjected to the structure enhancement processing by the structure enhancement unit 72 is input from the normal light image processing unit 62 to the image display signal generation unit 66 as normal light image processed RGB image data.

  The special light image processing unit 64 is a special light mode suitable for pre-processed digital image signals by blue-violet laser light (profile A) from 405LD33 and white light (profile B) from 445LD35 and phosphor 23 in the special light mode. This is a portion that performs image processing for light, and includes a special light color conversion unit 74, a color enhancement unit 76, and a structure enhancement unit 78.

  The special light color conversion unit 74 assigns the G image signal of the input preprocessed RGB 3-channel digital image signal to the R image data by applying a predetermined coefficient, and applies a different predetermined coefficient to the B image signal to give each of the G image signals to G. After assigning to the image data and B image data and generating the RGB image data, the color of the generated RGB image data, such as 3 × 3 matrix processing, gradation conversion processing, three-dimensional LUT processing, etc., as with the color conversion unit 68 Perform the conversion process.

  Specifically, the special light color conversion unit 74 normalizes the luminance of the assigned R, G, and B image data, and generates Rnorm, Gnorm, and Bnorm image data. Next, the normalized Rnorm, Gnorm, Bnorm image data is corrected to a color tone according to the light amount ratio. If the image data after color correction is Radj, Gadj, Badj image data, the Radj, Gadj, Badj image data after color correction is obtained by the calculation shown in the following equation (1).

  Here, KR, KG, and KB are color conversion coefficients for the respective colors, and are obtained according to the light amount ratio calculated by the light amount ratio calculation unit 56. As illustrated in FIG. 6, the special light color conversion unit 74 includes a color conversion coefficient table 80 in which color conversion coefficients for each color corresponding to the light amount ratio (light amount ratio) are determined. Based on the calculated light amount ratio, From the conversion coefficient table 80, color conversion coefficients KR, KG, and KB are determined.

  As shown in FIG. 6, the color conversion coefficients KR, KG, KB in the color conversion coefficient table 80 correspond to the respective light quantity ratios R00, R01, R02,..., G00, G01, G02,. , B02,... By substituting the color conversion coefficient corresponding to the light amount ratio calculated by the light amount ratio calculation unit 56 into Equation 1, image data Radj, Gadj, and Badj whose colors have been corrected are obtained.

  For example, when the ratio of the light amount of 405LD33 and the light amount of 445LD35 controlled by the light source control unit 48 is 100: 10, that is, the light amount ratio is 405LD: 445LD≈90.9: 9.1, the color conversion coefficient is From the color conversion coefficient table shown in FIG. 6, (KR, KG, KB) = (R10, G10, B10) is obtained. This color conversion coefficient is not limited to the table shown in FIG. 6, but may be expressed as a mathematical expression. Alternatively, only representative points may be converted into numerical values and other points may be obtained by interpolation.

  Similar to the color enhancement unit 70, the color enhancement unit 76 adds a color difference between the blood vessels and the mucous membrane in the screen to enhance the blood vessels so that they can be easily seen. A process of looking at the image data while looking at the screen, for example, a process of looking at the average color tone of the entire screen and emphasizing the color tone in the direction of adding a color difference between the blood vessel and the mucous membrane from the average value. Do.

  Similar to the structure emphasizing unit 72, the structure emphasizing unit 78 performs structural processing such as sharpness and edge emphasis on the color-enhanced RGB image data. The RGB image data that has been subjected to the optimum frequency enhancement processing by the structure enhancement unit 78 is output from the special light image processing unit 64 to the image display signal generation unit 66 as special light image processed RGB image data.

  Further, as described above, when the amount of light emitted from the blue laser light source (445LD) 35 is increased due to insufficient light amount, the amount of light for imaging is sufficient, but the color tone of the captured image is changed, and special light is observed. Information on the captured image regarding the fine structure of the superficial blood vessel also becomes inconspicuous. Therefore, the special light image processing unit 64 may perform frame addition processing or binning processing in order to emphasize the surface blood vessels on the captured image before the color conversion unit 68.

  Here, the frame addition process is usually a process of adding a plurality of frames for generating one image in one frame, and the binning process is a process of integrating a plurality of pixels constituting the image. Note that the charge accumulation time of the image sensor 21 may be lengthened in advance instead of the frame addition process and the binning process. The same effect as the frame addition process can be obtained.

  The image display signal generation unit 66 receives the image processed RGB image data input from the normal light image processing unit 62 in the normal light mode, and the image processed RGB image data input from the special light image processing unit 64 in the special light mode. Are converted into display image signals. The display image signal is displayed on the monitor 38 as a soft copy image and is output to the recording device 42. The display image signal recorded in the recording device 42 is output from the recording device 42 as a hard copy image.

  In the normal light mode, a normal observation image based on a display image signal that is imaged by the imaging device 21 by irradiating white light and subjected to preprocessing and normal light image processing by the processor device 14 is displayed on the monitor 38 as a soft copy image. Is displayed. In the special light mode, a special light observation image based on a display image signal that is imaged by the imaging device 21 by irradiating special light in addition to white light and pre-processed and special light image processing by the processor device 14 is displayed on the monitor 38. Displayed as a soft copy image.

  The recording device 42 also outputs a normal observation image obtained by irradiating white light in the normal light mode as a hard copy image, and special light observation obtained by irradiating white light and special light in the special light mode. Output the image as a hard copy image. If necessary, the display image signal generated by the image display signal generation unit 66 may be stored as image information in a storage unit including a memory or a storage device (not shown).

  On the other hand, the mode switching unit (input unit) 40 has a mode switching button for switching between the normal light mode and the special light mode, and the mode switching signal from the mode switching unit 40 is a light source control unit 48 of the light source device 16. Is input. Here, the mode switching unit 40 is disposed as the input unit 40 of the input / output unit (the monitor 38, the recording device 42, and the mode switching unit 40 in FIG. 4), but the operation of the processor device 14 and the electronic endoscope 12 is performed. Or the light source device 16. Note that the switching signal from the mode switching unit 40 is output to the light source control unit 48 and the image processing switching unit 60.

  Next, the operation of the endoscope system in the embodiment having the above-described configuration will be described with reference to FIGS. In the present embodiment, first, it is assumed that normal light observation is performed in the normal light mode. That is, the 445LD 35 is turned on, and the normal light image processing unit 62 performs normal light image processing on the captured image data using white light.

  Here, switching to the special light mode is performed by the user according to the processing procedure shown in FIG. When the user operates the mode switching unit 40, a mode switching signal (special light ON) is output, and the image processing in the image processing switching unit 60 is switched to the special light mode (step S10).

  When switched to the special light mode, the light amount of the light source is adjusted in the next step S20. The adjustment of the amount of light emitted from the light source must always be performed according to the change in the positional relationship between the endoscope tip and the subject. FIG. 8 is a flowchart showing a detailed processing procedure of light amount adjustment when the position of the endoscope tip and the subject is fixed.

  First, in step S120 of FIG. 8, a predetermined amount of narrowband light (405 nm) is emitted from the blue-violet laser beam (405LD) 33, and narrowband light (illumination light) is directed toward the subject from the distal end of the endoscope. 405 nm) and its excitation emission light (fluorescence of the phosphor 23). The irradiated illumination light is reflected by the subject, and the return light is acquired as captured image information by the image sensor 21 (step S122).

  When the image information at the time of imaging is acquired, the captured image information is output to the light amount calculation unit 50 via the CDS / AGC 44 and the A / D conversion unit 46, and the light amount of the return light (the luminance of the captured image) in the image sensor 21. Value) is calculated (step S124). The calculated amount of return light is output to the light source controller 48.

  Based on the light amount calculated by the light amount ratio calculation unit 56, the light source control unit 48 determines whether the light amount is sufficient, that is, whether the amount of return light is greater than or equal to a predetermined value (step S126). If the amount of light is sufficient, it is not necessary to change the amount of light emitted at that position, the light amount of the light source is not adjusted, and the process proceeds to the subject imaging process (step S30) in FIG. Of course, when there is too much light and the image sensor 21 overflows, control is performed to reduce the current value of the drive current flowing through the 405LD 33.

  If the amount of light is insufficient, the light source control unit 48 determines whether the output of the 405LD33 is maximum from the current value of the drive current flowing through the 405LD33 (step S128).

  When the output of 405LD is not the maximum, the light source control unit 48 increases the output (current value of the drive current) of 405LD33 by a predetermined amount (step S130), and calculates the light amount again (step S124).

  When the output of 405LD33 is maximum, the light source control unit 48 determines whether or not the blue laser light source (445LD) 35 is lit (step S132). If the 445LD 35 is not lit, the 445LD 35 is lit (step S134), and the light amount is calculated again (step S124). When the 445LD 35 is turned on, the narrow band light (405 nm) and the excitation emission light are superimposed on the narrow band light (405 nm) and the excitation emission light as illumination light, and the subject is irradiated from the distal end of the endoscope.

  If the 445LD 35 is already lit, the output of the 445LD 35 is increased (step S136), and the light amount is calculated again (step S124). In this way, the amount of emitted light is adjusted based on the steps in FIG. 8 until the amount of return light in the image sensor 21 becomes equal to or greater than a predetermined value.

  Although not described in the processing procedure of FIG. 8, if the amount of light is insufficient even when the output of 445LD35 is maximized, the subject imaging process (step S30) shown in FIG. Adjust the position of the mirror tip and the subject again, and bring the endoscope tip closer to the subject.

  Here, the operation of adjusting the amount of light when the position of the endoscope tip and the subject is fixed has been described, but as described above, the amount of light emitted from the light source is fixed and the position of the endoscope tip and the subject is changed. May be. In this case, as described above, the amount of light emitted from the 405LD33 is set to a predetermined value, the 445LD35 is stopped and the positional relationship between the endoscope tip and the subject is changed, and the amount of light emitted from the 405LD33 is maximized. As a predetermined value, two operations may be considered: changing the positional relationship between the endoscope tip and the subject.

  When only 405LD33 is used, it is mainly used when imaging is performed by bringing the tip of the endoscope close to the subject, and when the amount of emitted light of 405LD33 is maximized and the amount of emitted light of 445LD35 is set to a predetermined value, This is mainly used when imaging is performed with the distal end of the endoscope far away from the subject.

  When the light amount is adjusted (step S20 in FIG. 7), the subject is imaged in step S30, and captured image information is acquired by the image sensor 21. The captured image information is appropriately processed by the CDS / AGC 44 and the A / D converter 36 as described above, and is output to the light amount ratio calculation unit 56.

  The light quantity ratio calculation unit 56 calculates the light quantity of B light and the light quantity of G light from the captured image information, and outputs them to the light quantity ratio calculation unit 56 (step S32). The captured image information is output as a captured image signal to the special light image processing unit 64 through the DSP 52 and the noise removal circuit 54.

  The light quantity ratio calculation unit 56 acquires information on the emitted light quantity of the 405LD33 and the emitted light quantity of the 445LD35 from the light source control unit 48, and calculates the light quantity ratio between the 405LD33 and the 445LD35 (step S34). The calculated light amount ratio is output to the special light color conversion unit 74 of the special light image processing unit 64.

  The special light color conversion unit 74 of the special light image processing unit 64 determines the color conversion coefficients KR, KG, KB used for the special light color conversion from the calculated light quantity ratio information and the color conversion coefficient table 80 ( Along with step S36), the captured image signal input to the special light image processing unit 64 is converted into special light image data (step S38). Note that image enhancement processing such as frame addition processing may be performed before special light color conversion.

  In the next step S40, the special light image data in step S38 is converted to a pseudo color image (RGB image data) by applying the color conversion coefficient in step S36. Then, the color enhancement unit 76 and the structure enhancement unit 78 perform various kinds of image processing on the RGB image data (step S42), and then output to the image display signal generation unit 66 to generate an image display signal ( Step S44). In the final step 46, this image display signal is displayed on the monitor 38 as a special light image, recorded in the recording device 42, and this processing procedure is completed.

  In the above-described embodiment, either the normal light image processing unit 62 or the special light image processing unit 64 is selected by the image processing switching unit (switch) 60 in FIG. By switching, an observation image obtained by superimposing an observation image of special light on an observation image of normal light can be displayed on the monitor 38.

  In the endoscope system described above, a total of four light sources are used as the light sources, two of the blue-violet laser light sources 33a and 33b having an emission wavelength of 405 nm and two of the blue laser light sources 35a and 35b having an emission wavelength of 445 nm. It is provided in the device 16. While the electronic endoscope 12 is being inserted into the body cavity of the patient, any one of the light sources may turn off due to a failure.

  When a failure occurs in the light source, it is possible to remove the electronic endoscope 12 from the patient's body cavity, and replace the failed light source with another normal light source and continue examination of the patient with the endoscope. It is also possible. This determination is performed by a doctor. In the endoscope system of the present embodiment, the following drive control is performed when an abnormality occurs in any one of the light sources in order to support the doctor's determination.

  FIG. 9 is an explanatory diagram of a failure detection circuit for a laser light source. Each laser light source LD is driven by a constant current driver, for example. Therefore, the failure detection circuit 91 detects the anode potential VA and the cathode potential Vk of the laser light source LD, obtains the forward drop voltage Vf (= VA−Vk) from the difference therebetween, and uses the voltages Vk, VA, and Vf. Detect failure. For example, when VA≈Vk, it can be detected as “short circuit occurrence”, and when Vk≈0 V and VA >> Vf, it can be detected as “disconnection occurrence”.

  FIG. 10 is a diagram showing failure patterns (normal (◯), abnormality (×)) of four light sources and restrictions on observation modes. Here, among the light sources of the respective emission wavelengths, the main lamps 33a and 35a are labeled “LD1”, and the spare lamps 33b and 35b are labeled “LD2”.

  The failure pattern 1 is a case in which one of the two lamps having a wavelength of 445 nm fails and both of the two lamps having a wavelength of 405 nm are normal. In this case, the driving control of the observation mode restriction A is performed.

  Failure pattern 2 is a case where both of the two lights having a wavelength of 445 nm are normal and one of the two lights having a wavelength of 405 nm has failed. In this case, the driving control of the observation mode restriction B is performed.

  The failure pattern 3 is a case where both of the two lamps having a wavelength of 445 nm have failed. In this case, the driving control of the observation mode restriction C is performed.

  The failure pattern 4 is a case where both of the two lights having a wavelength of 445 nm are normal, but both of the two lights having a wavelength of 405 nm have failed. In this case, the driving control of the observation mode restriction D is performed.

  The failure pattern 5 is a case where one of the two lights having a wavelength of 445 nm fails and one of the two lights having a wavelength of 405 nm has failed. In this case, drive control of the observation mode restriction E is performed. .

  The drive control of the observation mode restriction A is performed as follows. In failure pattern 1, since one of the 445 nm light sources, which is a bright light source, has failed, only one 445 nm light source can be used.

  FIG. 11 is a diagram illustrating an example of a warning display that is superimposed on the observation image 92 of the monitor 38 in the case of the failure pattern 1. In the case of failure pattern 1, a warning message “Failure occurrence: pull out the scope. Observation can be continued for a short time” is displayed.

  In the case of this failure pattern 1, since the illumination light becomes darker than when 445 nm two lights are used simultaneously in parallel, when the doctor chooses to continue observation, drive control is performed to compensate for the insufficient light quantity with a 405 nm light source. In this case, since the proportion of B light in the illumination light increases compared to before the failure occurs, when image processing is performed on the captured image, image processing is performed in consideration of the increase in the B light proportion. In order to prevent a change in color in the observed image.

  The driving control of the observation mode restriction B is performed as follows. In failure pattern 2, since the two 445 nm light sources are normal, there is no problem with observation using normal light. For this reason, it is sufficient to display a warning indicating that a trouble occurs in the special light observation mode.

  When the special light observation is continued, one of the two lights of 405 nm is out of order, so that the illumination light of the special light becomes darker than when using two lights of 405 nm simultaneously in parallel. Therefore, in the observation mode restriction B, the shortage of the image signal obtained with the 405 nm illumination light is supplemented with the image signal obtained with the 445 nm illumination light.

  That is, the value of the predetermined coefficient used in the image processing of the pseudo color image generated from the B image signal and the G image signal of the superficial blood vessel obtained by the B light and the G light is set to a different value before and after the failure occurrence. In order to prevent a change in color in the observed image.

  The driving control of the observation mode restriction C is performed as follows. In failure pattern 3, two 445 nm lamps have failed, and bright illumination light cannot be obtained. For this reason, in this observation mode restriction C, as shown in FIG. 12, a warning display “Please pull out the scope immediately” blinks to notify that there is no other option. Since the illumination light of 405 nm is dark, the gain for the output signal of the solid-state image sensor is increased to brighten the observation image as much as possible so that the electronic endoscope 12 can be quickly removed.

  The drive control of the observation mode restriction D is performed as follows. In failure pattern 4, since two 445 nm light sources are normal, there is no problem in observation using normal light. For this reason, it is sufficient to display a warning indicating that a trouble occurs in the special light observation mode. In failure pattern 4, since both 405 nm lamps are in failure, 405 nm illumination light cannot be used. For this reason, when observing an image of a superficial blood vessel, the illumination light of 445 nm is used. That is, the same image processing as in the observation mode restriction B is performed, but the failure pattern 4 does not include any 405 nm illumination light. become.

  The drive control of the observation mode restriction E is performed as follows. The failure pattern 5 has one light source of 405 nm less than the failure pattern 1. For this reason, in the observation mode restriction E, the shortage of illumination light of 445 nm is compensated by one light source of 405 nm. That is, in this observation mode restriction E, the ratio of the B light is different from the observation mode restriction A. Therefore, the coefficients used in the image processing to prevent the color of the observation image from changing before and after the failure are different from the observation mode restriction A. .

As described above, in the endoscope system and the driving method thereof according to the embodiment, a solid-state imaging device that irradiates the subject with illumination light from the tip and receives light from the subject is mounted on the tip. An electronic endoscope; and a light source device that includes a plurality of light sources, introduces light emitted from the light sources into the electronic endoscope, and irradiates the subject with the emitted light as the illumination light. Endoscopy system and driving method thereof
When any one of the plurality of light sources is extinguished due to a failure, the illumination light of a normal light source is replaced with the illumination light of the normal light source instead of the light source related to the failure, and the light source related to the failure is in a normal state. When the illumination light and the illumination light of the substituted light source are different, the image processing of the captured image signal output from the solid-state imaging device is switched to change the color change of the captured image after the image processing before and after the substitution. It is characterized by suppressing.

  In the endoscope system and the driving method thereof according to the embodiment, when at least one of the amount of light and the emission wavelength of the illumination light of the substitute light source when it is normal and the illumination light of the alternative light source are different The image processing is switched.

  In addition, the endoscope system and the driving method thereof according to the embodiment are characterized in that a warning is displayed on a monitor screen that displays a captured image of the solid-state imaging device when the failure occurs.

  In addition, in the endoscope system and the driving method thereof according to the embodiment, as the light source, at least two semiconductor light emitting elements that emit light in the first wavelength range and at least one semiconductor light emitting element that emits light in the second wavelength range are used. And a phosphor that receives light emitted from the semiconductor light emitting element and emits yellow fluorescent light is incorporated in the distal end portion of the electronic endoscope.

  In addition, in the endoscope system and the driving method thereof according to the embodiment, when any one of the plurality of light sources that emit light in the first wavelength band fails and at least one of the plurality of light sources is normal, The acquired image is continuously acquired from the solid-state image sensor even after the failure, and when all of the plurality of light sources emitting light in the first wavelength range fail, the light source emitting light in the second wavelength range A warning display for instructing removal of the electronic endoscope from the body cavity is displayed on the monitor screen using emitted light as illumination light.

  According to the embodiment described above, even when one of the light sources fails in an endoscope system equipped with a plurality of light sources, the normal light source can be substituted for the failed light source and observation with the endoscope can be continued. When the light source is replaced, the color change of the observation image can be suppressed before and after the replacement, and high-precision observation can be continued, and the burden on the patient can be reduced.

  The endoscope system according to the present invention can continuously examine a patient with an endoscope even when one of a plurality of light sources fails, so that the burden on the patient can be reduced. It is useful when applied to an on-board endoscope system.

10 Endoscope system 12 Electronic endoscope (scope)
14 processor device 16 light source device 21 imaging device 23 phosphor 25 illumination window 26 tip 27 illumination window 31 CPU
33a, 33b Laser light emitting light sources 35a, 35b having a wavelength of 405 nm Laser light emitting light sources 37 having a wavelength of 445 nm Image processing system 38 Monitor

Claims (10)

An electronic endoscope in which a solid-state imaging device that irradiates illumination light to the subject from the tip and receives light from the subject is mounted on the tip;
A light source device that includes a plurality of light sources, introduces light emitted from the light sources into the electronic endoscope, and irradiates the subject with the light emitted as the illumination light;
When any one of the plurality of light sources is extinguished due to a failure, the illumination light of a normal light source is replaced with the illumination light of the normal light source instead of the light source related to the failure, and the light source related to the failure is in a normal state. When the illumination light and the illumination light of the substituted light source are different, the image processing of the captured image signal output from the solid-state imaging device is switched to change the color change of the captured image after the image processing before and after the substitution. An endoscopic system comprising a control means for suppressing.   The endoscope system according to claim 1, wherein at least one of a light amount and a light emission wavelength of the illumination light of the light source in the normal state and the illumination light of the substituted light source is different, An endoscope system for switching the image processing.   The endoscope system according to claim 1 or 2, wherein when the failure occurs, the endoscope system displays a warning on a monitor screen that displays a captured image of the solid-state imaging device.   The endoscope system according to any one of claims 1 to 3, wherein the light source includes at least two semiconductor light emitting elements that emit light in a first wavelength region and light in a second wavelength region. An endoscope including at least one semiconductor light emitting element that emits light, and a phosphor that receives light emitted from the semiconductor light emitting element and emits yellow fluorescent light at the distal end portion of the electronic endoscope. system.   5. The endoscope system according to claim 4, wherein any one of a plurality of light sources that emit light in the first wavelength band fails and at least one of the plurality of light sources is normal. Light emission of a light source that emits light in the second wavelength range when all of the plurality of light sources that emit light in the first wavelength range fail, continuously acquiring the captured image from the solid-state imaging device. An endoscope system that displays on the monitor screen a warning display that instructs removal of the electronic endoscope from a body cavity using light as illumination light. An electronic endoscope in which a solid-state imaging device that irradiates illumination light to the subject from the tip and receives light from the subject is mounted on the tip;
A driving method of an endoscope system, comprising: a plurality of light sources; a light source device that introduces light emitted from the light sources into the electronic endoscope and irradiates the subject with the light emitted as the illumination light. Because
When any one of the plurality of light sources is extinguished due to a failure, the illumination light of a normal light source is replaced with the illumination light of the normal light source instead of the light source related to the failure, and the light source related to the failure is in a normal state. When the illumination light and the illumination light of the substituted light source are different, the image processing of the captured image signal output from the solid-state imaging device is switched to change the color change of the captured image after the image processing before and after the substitution. A driving method for an endoscope system, characterized by comprising:   7. The driving method of an endoscope system according to claim 6, wherein at least one of a light quantity and a light emission wavelength of illumination light when the light source affected by the failure is normal and illumination light of the alternative light source is selected. An endoscope system driving method for switching the image processing when different.   The driving method of the endoscope system according to claim 6 or 7, wherein a warning is displayed on a monitor screen that displays a captured image of the solid-state imaging device when the failure occurs. Method.   9. The driving method of the endoscope system according to claim 6, wherein the light source includes at least two semiconductor light emitting elements that emit light in a first wavelength range and a second wavelength range. 10. And at least one semiconductor light emitting element that emits the light of the above-mentioned type, and a phosphor that receives the light emitted from the semiconductor light emitting element and emits yellow fluorescent light is built in the tip portion of the electronic endoscope. Driving method of endoscope system.   10. The endoscope system according to claim 9, wherein one of the plurality of light sources that emit light in the first wavelength band has failed and at least one of the plurality of light sources is normal. Light emission of a light source that emits light in the second wavelength range when all of the plurality of light sources that emit light in the first wavelength range fail, continuously acquiring the captured image from the solid-state imaging device. A driving method of an endoscope system, wherein a warning display for instructing removal of the electronic endoscope from a body cavity is displayed on the monitor screen using light as illumination light.

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