JP2010094152A - Electron endoscopic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electron endoscopic system for acquiring a usual light image and a special light image at the same time. <P>SOLUTION: The electron endoscopic system 11 includes an imaging element 31, a light source 61, a rotary filter 62 and a DIP 42. The imaging element 31 photoelectrically converts the light from a subject to image the subject, and the light source 61 emits the illumination light thrown on the subject. The rotary filter 62 is arranged in front of the light source 61 in a freely rotatable manner to rotate in synchronous relation to a plurality of times of the imaging steps by the imaging element 31, has a selective region selectively pervious to a narrow wavelength band component within at least one predetermined center angle of a fan-shaped section of which the predetermined center angle corresponds to one imaging by the imaging element 31 and also has a white light pervious region in the whole of the fan-shaped section. The DIP 42 forms a plurality of observation images, which are different in feature from each other, from the image data imaged during the rotation of the rotary filter 62. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic endoscope system that captures an inside of a subject and obtains an observation image, and more particularly relates to an electronic endoscope system that obtains a plurality of types of observation images while switching the wavelength of illumination light applied to the subject. .

  Conventionally, electronic endoscope systems have been widely used in the medical field. According to the electronic endoscope system, an elongated insertion portion of an electronic endoscope provided with a minute imaging device is inserted into a subject's body, and diagnosis and treatment are performed while imaging the subject's body in real time. It can be carried out.

  As a method for obtaining a full-color observation image with an electronic endoscope system, two types of imaging methods, a line sequential method and a frame sequential method, are known. The line-sequential method is an image pickup method in which a color filter in which RGB colors are arranged is arranged on an image pickup element and signals of RGB colors are acquired. The frame sequential method captures images while sequentially irradiating RGB illumination lights on the subject, combines the obtained images of the respective colors, and obtains the same single observation obtained when the illumination light is irradiated with white. This is an imaging method for obtaining an image.

  As described above, regardless of the imaging method, in the conventional electronic endoscope system, an observation image obtained when imaging is performed by irradiating white illumination light (hereinafter, normal light).

  However, depending on characteristics such as the depth from the surface and the size of the structure, the observation site may not be clearly observed with normal light. Things that are difficult to observe clearly with normal light include, for example, superficial blood vessels, pit patterns (gland opening structures), medium-scale uneven structures such as depressions and ridges, fine blood vessels, redness, thickening, and deep blood vessels . It is known that such a structure can be clearly observed by using light of a specific wavelength as illumination light.

  For example, the fine structure of the surface of the observation site such as a blood vessel or pit pattern in the surface layer can be observed with illumination light having a wavelength of around 450 nm, and a macro uneven structure such as a depression or a bulge in the observation site has a wavelength of around 500 nm. It can be observed with illumination light. Further, it is known that illumination light in the vicinity of a wavelength of 550 nm has a high absorption rate by hemoglobin, and is suitable for observation of fine blood vessels and redness, and illumination light in the vicinity of a wavelength of 600 nm is suitable for observation of thickening. Furthermore, the deep blood vessels can be observed clearly by injecting a fluorescent substance such as indocyanine green (ICG) intravenously and using light in the vicinity of a wavelength of 780 nm as illumination light.

Therefore, in recent years, in order to facilitate observation of structures that are difficult to observe with normal light, the illumination light having a narrow wavelength band as described above (hereinafter referred to as special light) is switched according to the structure to be observed. An electronic endoscope system that can be used is known (Patent Documents 1 and 2).
Japanese Patent No. 3586157 Japanese Patent No. 2686089

  In the inventions described in Patent Documents 1 and 2, in order to use normal light and various special lights while appropriately switching, a plurality of optical filters are provided in advance and the illumination light is switched by exchanging them. ing. However, in order to capture images with different characteristics by exchanging optical filters as in Patent Documents 1 and 2, depending on the type of characteristics of the subject to be imaged, the type of special light and the combination of special light are different. It is necessary to prepare a large number of filters in advance, and there is a problem that the configuration of the light source device that generates illumination light becomes complicated and expensive.

  In addition, when switching the illumination light by exchanging the optical filter, it takes a certain amount of time to switch the optical filter, so that an observation image with normal light (hereinafter referred to as a normal light image) and an observation image with special light ( Hereinafter, a special light image) cannot be obtained simultaneously. For this reason, when observing a subject that is constantly moving, such as inside the body of the subject, the orientation and shape of the subject change while switching the optical filter, so the normal light image and the special light image in the same state. There is a problem that comparative observation cannot be performed.

  The present invention has been made in view of the above-described problems, and it is possible to simultaneously acquire a plurality of observation images having different characteristics from each other, such as a normal light image and a special light image, with respect to a subject in the same state. An object of the present invention is to provide an electronic endoscope system that can be used.

  An electronic endoscope system according to the present invention includes an imaging unit that images a subject by photoelectrically converting light from the subject, a light source that generates illumination light that irradiates the subject, and a front light source that is rotatable. The wavelength is set in at least one of the sector-shaped sections among the sector-shaped sections having a predetermined central angle corresponding to one-time imaging by the imaging means. A white light transmission that has a selective transmission region that selectively transmits a wavelength band component narrower than a wavelength band to which the pixel of the image sensor is sensitive at the center, and transmits the wavelength band component of white light in all of the sector-shaped sections. A rotary filter having a region, and observation image generation means for generating a plurality of observation images having different characteristics from image data captured while the rotary filter rotates And wherein the door.

  The white light includes light having a wavelength band longer than 500 nm and shorter than 750 nm, light having a wavelength band shorter than 450 nm is 1/10 or less of the amount of light having a wavelength of 500 nm, and light having a wavelength band longer than 780 nm is 750 nm. It is 1/10 or less of the light quantity of the light of the wavelength.

  The light transmitted through the selective transmission region has a center wavelength in the vicinity of 450, 500, 550, 600, or 780 nm.

  The rotary filter has a light-shielding region that shields the illumination light corresponding to a charge reading period of the imaging means for each of the fan-shaped sections.

  The observation image generation means extracts color components from each of the plurality of image data, and calculates intermediate image data obtained when imaging is performed by irradiating illumination light transmitted through the selective transmission region. And

  The observation image generation unit generates an emphasized image in which a predetermined portion of the subject is emphasized from the intermediate image data.

  According to the present invention, the normal light image and the special light image can be acquired simultaneously, and the normal light image and the special light image can be easily compared. In addition, it is not necessary to prepare a large number of replacement optical filters, and the electronic endoscope system can be simply configured at low cost.

  As shown in FIG. 1, the electronic endoscope system 11 includes an electronic endoscope 12, a processor device 13, a light source device 14, and the like. The electronic endoscope 12 includes an insertion unit 16, a hand operation unit 17, a universal cord 18, and the like.

  The insertion unit 16 is inserted into the body of the subject (hereinafter referred to as a subject) and is freely curved according to the shape of the subject. In addition, an imaging device incorporating an imaging element 31 (see FIG. 2) is provided at the distal end portion 16a of the insertion portion 16.

  On the end face of the distal end portion 16a, there are an illumination window 16b that irradiates illumination light forward, an observation window 16c that guides light from the subject to the image sensor 31 (see FIG. 2), a forceps outlet from which various treatment tools are exposed, An air supply / water supply nozzle or the like for injecting cleaning water or air is provided.

  A bending portion 19 is provided behind the distal end portion 16a. The bending portion 19 is formed by connecting a plurality of bending pieces, and a wire inserted through the insertion portion 16 is connected to an angle knob 21 provided in the hand operation portion 17. The bending portion 19 is freely bent up and down and left and right as the wire is pushed and pulled according to the rotation operation of the angle knob 21. Thereby, the position and orientation of the tip portion 16a are freely adjusted in a desired direction.

  The hand operation unit 17 is provided with various operation buttons 23 such as a forceps port 22 and an air / water supply button in addition to the angle knob 21 for operating the bending portion 19 as described above. Various treatment tools such as an injection needle and a high-frequency knife are inserted into the forceps port 22. Various treatment tools inserted from the forceps port 22 are exposed from the forceps outlet toward the subject as described above. The air / water supply button controls the air and water supplied from an air / water supply device (not shown).

  The universal cord 18 optically connects the electronic endoscope 12 and the light source device 14 by a connector 24 provided at a proximal end portion. The universal cord 18 electrically connects the electronic endoscope 12 to the processor device 13 at the other end of the connector 24.

  The processor device 13 is connected to the electronic endoscope 12, the light source device 14, the monitor 26, and the like, and comprehensively controls the operation of the electronic endoscope system 11. The light source device 14 irradiates illumination light toward the observation site of the subject through a light guide inserted through the universal cord 18 and the insertion portion 16.

  As shown in FIG. 2, the electronic endoscope 12 includes an image sensor 31, an AFE 32, a CPU 33, a light guide 34, and the like.

  The image sensor 31 is a CCD type image sensor, and an objective lens 36 is disposed in front thereof. The image pickup device 31 has any of RGB color filters arranged for each pixel, and photoelectrically converts light from the subject imaged on the image pickup surface by the objective lens 36 for each of the three basic colors of RGB, and the exposure amount. The signal charge corresponding to is accumulated. The image sensor 31 outputs the signal charge accumulated in each pixel as an image signal. An imaging signal from the imaging element 31 is input to the processor device 13 via the AFE 32. Here, a CCD image sensor is used as the image sensor 31, but a CMOS image sensor may be used as the image sensor 31.

  The AFE 32 includes a correlated double sampling circuit (CDS), an automatic gain control circuit (AGC), and an analog / digital conversion circuit (A / D). The CDS performs correlated double sampling processing on the image signal output from the image sensor 31 to remove noise generated by driving the image sensor 31. The AGC amplifies the imaging signal from which noise has been removed by CDS. The A / D converts the image signal amplified by the AGC into a digital image signal having a predetermined number of bits and inputs it to the processor device 13.

  The CPU 33 communicates with the CPU 41 of the processor device 13 and comprehensively controls the operation of each unit of the electronic endoscope 12. For example, the CPU 33 controls the operation of the image sensor 31 by causing the timing generator (TG) 37 to generate a predetermined timing signal based on a control signal from the CPU 41 of the processor device 13, and images the image sensor 31. Output a signal.

  The light guide 34 is inserted into the universal cord 18 and the insertion portion 16, one end is connected to the illumination window 16 b via the lens 38, and the other end is connected to the light source device 14 via the connector 24. Illumination light from the light source device 14 is irradiated through the light guide 34 from the illumination window 16b to the observation site of the subject.

  The processor device 13 includes a CPU 41, a DSP 43, a DIP 42 (observation image generating means), a display control circuit 44, and the like.

  The CPU 41 controls the operation of each unit of the processor device 13 connected via the system bus 47 by executing a control program stored in a ROM (not shown). Further, the CPU 41 communicates with the CPU 33 of the electronic endoscope 12 and the CPU 63 of the light source device 14 to control the operation of the electronic endoscope 12 and the light source device 14, thereby comprehensively controlling the electronic endoscope system 11. To do.

  The DSP 43 performs various image processing such as color interpolation, white balance adjustment, and gamma correction on the digital imaging signal input from the AFE 32, and is an image suitable for displaying the normal light image and the special light image on the monitor 26. Make data.

  The DIP 42 generates an observation image to be displayed on the monitor 26 from the image data output from the DSP 43. Further, the DIP 42 accumulates a plurality of image pickup signals input every time the subject is imaged in the frame memory as image data. The image data stored in the frame memory by the DIP 42 is image data for the number of times of imaging (in this case, twice) taken while the rotary filter 62 (described later) rotates once.

  The DIP 42 includes a normal light image generation unit 51 and a special light image generation unit 52. The normal light image generation unit 51 extracts the components for each of the RGB basic colors from the two image data stored in the frame memory, compares and calculates them, and obtains the image while illuminating with normal light. The amount of exposure for each pixel is calculated. (Hereinafter, the exposure amount of each pixel is simply referred to as a pixel value.) The normal light image generation unit 51 generates a normal light image using the pixel value thus calculated as the pixel value of each pixel. The normal light image generated by the normal light image generation unit 51 is stored again in the frame memory.

  The special light image generation unit 52 extracts the components for each of the RGB basic colors from the two image data stored in the frame memory, compares and calculates them, and obtains the image while illuminating with special light. A pixel value is calculated for each pixel. The special light image generation unit 52 generates a special light image in which a specific structure of the subject is emphasized by superimposing the pixel value of the special light on the normal light image generated by the normal light image generation unit 51. Further, the special light image generation unit 52 generates a plurality of special light images having different parts to be emphasized based on the setting of the electronic endoscope system 11 according to the type of the subject. The special light image generated by the special light image generation unit 52 is stored again in the frame memory. Further, the DIP 42 performs further additional image processing such as electronic scaling and edge enhancement processing on the normal light image and the special light image according to the control from the CPU 41.

  The display control circuit 44 superimposes display mask data that hides the invalid pixel portion on the normal light image or special light image that has been subjected to various image processing by the DIP 42, and character information such as the examination date and time and information of the patient and the operator. Or, an operation GUI is superimposed. In addition, the display control circuit 44 converts the normal light image or the special light image into a video signal corresponding to the display format and displays it on the monitor 26.

  The light source device 14 includes a light source 61, a rotary filter 62, a CPU 63, a position sensor 64, and the like.

  The light source 61 is a white high-intensity light source such as a xenon lamp that emits light in a wide wavelength band ranging from ultraviolet rays to visible light and infrared light with high luminance, and generates illumination light to irradiate the subject. The illumination light emitted from the light source 61 includes infrared light.

  The rotary filter 62 is provided in front of the light source 61 with a surface perpendicular to the optical path of the illumination light. The rotary filter 62 is rotatably provided in a predetermined direction. The central axis of the rotary filter 62 is located away from the optical path of the illumination light, and the illumination light is incident on a part of the surface of the rotary filter 62. On the surface of the rotary filter 62, a plurality of fan-shaped optical regions having different transmission wavelength bands and transmittances are arranged within a predetermined angle range (see FIG. 3). Thereby, the rotary filter 62 modulates the wavelength or the amount of transmitted light or transmits light when transmitting the illumination light. The rotary filter 62 is rotated by a motor 69 in conjunction with the operation of the image sensor 31, and the rotary filter 62 is rotated once by two imaging operations by the image sensor 31. The illumination light that has passed through the rotary filter 62 is incident on the light guide 34 through the diaphragm 67, the lens 68, and the like.

  The CPU 63 controls the operation of each unit of the light source device 14. Further, the CPU 63 communicates with the CPU 41 of the processor device 13 to control the operation of each unit in the light source device 14 so as to be synchronized with the operation of each unit of the processor device 13 and the electronic endoscope 12. For example, the CPU 63 controls on / off of the light source 61, rotation of the rotary filter 62, opening diameter of the diaphragm 67, and the like.

  The position sensor 64 detects the rotation angle of the rotary filter 62 and notifies the CPU 63 of it. Based on the signal from the position sensor 64, the CPU 63 controls the operation of the motor 69 so as to synchronize with the operation of the image sensor 31.

  As shown in FIG. 3, the rotary filter 62 is provided with a first white light transmission region 71 and a second white light transmission region 72 as white light transmission regions through which the wavelength band component of white light is transmitted. The rotary filter 62 includes a blue light transmission region 73 and a green light transmission region as selective transmission regions that selectively transmit a wavelength band component narrower than the wavelength band to which the pixels of the image sensor 31 are sensitive, centered on a certain wavelength. A region 74 and an infrared light transmission region 76 are provided. The blue light transmissive region 73, the green light transmissive region 74, and the infrared light transmissive region 76 have a half-value width narrower than the sensitive wavelength band of each of the RGB pixels of the image sensor 31, and each of blue light, green light, and infrared light. To Penetrate. Further, the rotary filter 62 is provided with a first light-shielding filter 77 and a second light-shielding filter 78 as a light-shielding region that shields illumination light corresponding to the charge readout period of the image sensor. Each area provided in these rotary filters 62 has a sector shape having a predetermined central angle.

  Further, the rotary filter 62 is rotated once for two times of image pickup by the image pickup device 31. Therefore, the rotary filter 62 rotates by 180 degrees (predetermined center angle) for one image pickup by the image pickup device 31. For this reason, during one imaging operation, a white light transmission region, a selective transmission region, or the like provided in a half of the rotary filter 62 (upper half or lower half in FIG. 3) crosses the front surface of the light source 61 in order. As a result, the illumination light whose wavelength, amount of transmitted light, etc. are modulated during one imaging is irradiated onto the subject.

  In the upper half section (fan section) 81 (hereinafter referred to as the first section) of the rotary filter 62, a first light shielding filter 77, a blue light transmission region 73, and a first white color along the rotation direction 82 of the rotary filter 62. A light transmission region 71 is provided in order. For this reason, when the illumination light is modulated by the first section 81, the light passes through the front of the light source 61 in the order of the first white light transmission region 71, the blue light transmission region 73, and the first light shielding filter 77.

  The first white light transmission region 71 is provided in the range of the central angle θ <b> 1 in the first section 81, and transmits light in the wavelength band of 480 nm or more and 750 nm or less of the illumination light from the light source 61. The wavelength band light transmitted through the first white light transmission region 71 includes a wavelength band to which each of the RGB pixels of the image sensor 31 is sensitive (see FIG. 7), and is substantially white light (hereinafter referred to as normal light). It is said). For this reason, while the 1st white light transmissive area | region 71 crosses the front of the light source 61, normal light is irradiated to a to-be-photographed object as illumination light. Normal light (white light) includes light having a wavelength band longer than 500 nm and shorter than 750 nm, and light having a wavelength band shorter than 450 nm has a wavelength band shorter than 1/10 of the amount of light having a wavelength of 500 nm and longer than 780 nm. The light is preferably 1/10 or less of the amount of light having a wavelength of 750 nm.

  The blue light transmission region 73 is provided adjacent to the first white light transmission region 71 in the range of the central angle α of the first section 81 and is 450 nm narrower than the wavelength band to which the B pixel of the image sensor 31 is sensitive. Light in a nearby wavelength band (hereinafter referred to as blue special light) is selectively transmitted. For this reason, while the blue light transmission region 73 crosses the front of the light source 61, only the blue special light is irradiated to the subject as illumination light. Since the blue special light is strongly reflected near the surface of the subject, the surface blood vessels and pit patterns are imaged while the blue special light is irradiated as illumination light.

  The first light blocking filter 77 is provided in the range of the central angle ω of the first section 81 adjacent to the blue light transmission region 73 and blocks the illumination light of the entire wavelength band from the light source 61. Accordingly, the illumination light is not irradiated on the subject while the first light blocking filter 77 crosses the front of the light source 61. Further, the timing at which the first light blocking filter 77 crosses the front of the light source 61 is the signal charge accumulated in each pixel while the first white light transmission region 71 and the blue light transmission region 73 pass, and the image pickup device 31 takes the image signal. Corresponds to the transfer timing. Note that the period during which the imaging element 31 transfers the imaging signal is the same as or shorter than the period during which the first light blocking filter 77 crosses the front of the light source 61.

  On the other hand, in the lower half section (fan section) 83 (hereinafter referred to as the second section) of the rotary filter 62, along the rotation direction 82 of the rotary filter 62, a second light blocking filter 78, an infrared light transmission region 76, A green light transmission region 74 and a second white light transmission region 72 are provided in this order. For this reason, when the illumination light is modulated by the second section 83, the front of the light source 61 is placed in the order of the second white light transmission region 72, the green light transmission region 74, the infrared light transmission region 76, and the second light shielding filter 78. Cross.

  The second white light transmission region 72 is provided in the range of the central angle θ 2 adjacent to the first light shielding filter 77. The second white light transmission region 72 has the same configuration and function as the first white light transmission region 71.

  The green light transmission region 74 is provided in the range of the central angle β adjacent to the second white light transmission region 72, and is 550 nm in the wavelength band (see FIG. 7) to which the G pixel of the image sensor 31 is sensitive. Light in a narrow wavelength band in the vicinity (hereinafter referred to as green special light) is selectively transmitted. For this reason, while the green light transmission region 74 crosses the front of the light source 61, only the green special light is irradiated to the subject as illumination light. Since the green special light is strongly absorbed by hemoglobin, redness, fine blood vessels, and the like are imaged while the green special light is irradiated as illumination light.

  The infrared light transmission region 76 is provided in the range of the central angle γ adjacent to the green light transmission region 74 and transmits infrared in a narrow wavelength band near 780 nm (hereinafter referred to as infrared special light). . The infrared special light is infrared light in a wavelength band in which the R pixel of the image sensor 31 is not sensitive (see FIG. 7). For this reason, when the infrared light transmission region 76 crosses the front of the light source 61, only the infrared special light that the imaging device 31 is insensitive is irradiated as illumination light, but the infrared special light reflected on the subject causes No image is taken.

  However, the infrared special light is efficiently absorbed by a certain type of fluorescent material, and the fluorescent material that has absorbed the infrared special light generates fluorescence of a predetermined wavelength. For this reason, for example, when ICG is intravenously injected as a fluorescent substance, infrared special light is irradiated as illumination light, and fluorescence having a wavelength of around 830 nm is generated from a part of a subject such as a deep blood vessel. In addition, the R pixel of the image sensor 31 is not sensitive to infrared special light as described above, but is sensitive to fluorescence emitted from the ICG. For this reason, when the infrared light transmission region 76 crosses the front of the light source 61, a deep blood vessel or the like is imaged by the fluorescence from the fluorescent material.

  The second light shielding filter 78 is provided in the range of the central angle ω adjacent to the infrared light transmission region 76 in the same manner as the first light shielding filter 77, and shields the illumination light in the entire wavelength band from the light source 61. The configuration and operation of the second light shielding filter 78 are the same as those of the first light shielding filter 77. In addition, the period during which the image pickup element 31 transfers the image pickup signal is also the same as or shorter than the period during which the second light shielding filter 78 crosses the front of the light source 61.

  Hereinafter, the operation of the electronic endoscope system 11 configured as described above will be described. First, when the insertion unit 16 is inserted into a subject and observation is started, the rotary filter 62 is rotationally controlled by the CPU 63 in synchronization with the imaging operation of the imaging device 31 as shown in FIG.

  As shown in FIG. 4A, the image sensor 31 is configured to perform two imaging operations based on an instruction from the processor device 13 when the signal charge accumulation and the readout of the accumulated signal charge are one imaging operation. As a set, a plurality of sets of imaging are repeated at a predetermined timing. At this time, as shown in FIG. 4B, the rotary filter 62 irradiates the subject with illumination light modulated by either the first section 81 or the second section 83 in each imaging.

  The rotary filter 62 is rotated so that the first section 81 crosses the front of the light source 61 in the first half imaging period 91 (hereinafter referred to as a first imaging period) of one set of imaging of the imaging element 31. Therefore, in the signal charge accumulation period 92 (hereinafter referred to as the first accumulation period) in the first imaging period 91, the illumination light is modulated in order by the first white light transmission region 71 and the blue light transmission region 73. For this reason, in the first accumulation period 92, a signal charge of an amount obtained by combining the signal charge due to the normal light and the signal charge due to the blue special light is accumulated in each pixel of the image sensor 31.

  During the first accumulation period 92, the R pixel accumulates an amount of signal charge corresponding to the amount of the red component of the normal light transmitted through the first white light transmission region 71. Similarly, during the first accumulation period 92, the G pixel accumulates an amount of signal charge corresponding to the amount of the green component of the normal light transmitted through the first white light transmission region 71.

  Further, the total amount of signal charges accumulated in the B pixel during the first accumulation period 92 is such that the signal charge proportional to the amount of the blue component of the normal light transmitted through the first white light transmission region 71 and the blue light transmission. The total amount of signal charges is proportional to the amount of blue special light transmitted through the region 73.

  The signal charges accumulated in each pixel in the first accumulation period 92 are output as an image signal to the DIP 42 via the AFE 32 in the readout period 93 (hereinafter referred to as the first readout period) in the first imaging period 91. . Further, during the first readout period 93, illumination light from the light source 61 is blocked by the first light blocking filter 77.

  As described above, the illumination light is modulated by the first section 81 in the first imaging period 91, but in the second imaging period 96 (hereinafter referred to as the second imaging period) in one set of imaging of the imaging element 31, As shown in FIG. 4B, the rotary filter 62 is rotated so that the second section 83 crosses the front of the light source 61. Therefore, in the signal charge accumulation period 97 (hereinafter referred to as the second accumulation period) in the second imaging period 96, the illumination light is sequentially emitted by the second white light transmission region 72, the green light transmission region 74, and the infrared light transmission region 76. Modulated. For this reason, in the second accumulation period 97, the signal charge of the image sensor 31 has an amount of the signal charge due to the normal light, the signal charge due to the green special light, and the signal charge due to the fluorescence caused by the infrared special light. Accumulated in each pixel.

  For this reason, in the B pixel, during the second accumulation period 97, an amount of signal charge proportional to the amount of the blue component of the normal light transmitted through the second white light transmission region 72 is accumulated.

  On the other hand, the total amount of signal charges accumulated in the R pixel during the second accumulation period 97 is equal to the amount of signal charge proportional to the amount of red component of normal light transmitted through the second white light transmission region 72, and red The total amount of signal charges is proportional to the amount of fluorescent light generated by the external special light. Further, the total amount of signal charges accumulated in the G pixel during the second accumulation period 97 is equal to the amount of signal charges proportional to the amount of green component of normal light transmitted through the second white light transmission region 72, and green. It is the sum of the signal charges in an amount proportional to the amount of special light.

  The signal charges accumulated in each pixel in the second accumulation period 97 are output as an image signal to the DIP 42 via the AFE 32 in a readout period 98 (hereinafter referred to as a second readout period) in the second imaging period 96. . During the second readout period 98, the illumination light from the light source 61 is blocked by the second light blocking filter 78.

  Note that the amount of normal light transmitted through the first white light transmission region 71 and the pixel value of each pixel thereby are determined by the normal light transmittance of the first white light transmission region 71 and the central angle θ1. Similarly, the pixel value of the second white light transmission region 72 is determined by the normal light transmittance of the second white light transmission region 72 and the central angle θ2. Further, the ratio of the pixel values of the pixels of the first white light transmission region 71 and the second white light transmission region 72 according to the ratio of the amount of transmitted normal light of the first white light transmission region 71 and the second white light transmission region 72. Is determined.

  Further, the amount of transmitted blue special light through the blue light transmission region 73 and the pixel value thereby are proportional to the product of the transmittance of the blue special light in the blue light transmission region 73 and the central angle α. Similarly, the amount of green special light transmitted through the green light transmission region 74 and the resulting pixel value are proportional to the product of the green special light transmittance of the green light transmission region 74 and the central angle β. On the other hand, the amount of infrared special light transmitted by the infrared light transmission region 76 is proportional to the product of the transmittance of the infrared special light of the infrared light transmission region 76 and the central angle γ. Furthermore, it is proportional to the efficiency with which infrared special light is converted into fluorescence by the fluorescent substance.

  As described above, when the subject is imaged while the rotary filter 62 and the image sensor 31 are driven in synchronization, as shown in FIG. 5A, the first image data is obtained from the image signal output in the first imaging period 91. 101 is acquired. At the same time, as shown in FIG. 5B, the second image data 102 is acquired from the imaging signal output in the second imaging period 96. For this reason, after the first image data 101 is acquired, only an imaging period (for example, 1/30 seconds) for one frame elapses until the second image data 102 is acquired. As described above, since the first image data 101 and the second image data 102 are acquired substantially simultaneously, the first image data 101 and the second image data 102 are not affected by the movement of the subject, and the same subject is used. It can be handled as captured image data.

  Further, as described above, since the image signal output in the first image capturing period 91 is superimposed with the exposure of the normal light and the blue special light, as shown in FIG. 5A, the first image data 101 is displayed. The subject image (shown by a solid line) captured with normal light is overlaid with the subject image (shown schematically by a broken line) with blue special light, and the image with blue special light with a small amount of exposure is not very conspicuous Absent.

  Further, as described above, the imaging signal output in the second imaging period 96 is also superimposed with the exposure by the normal light, the green special light, and the infrared special light, as shown in FIG. In the second image data 102, a subject image (schematically indicated by a broken line) of green special light or infrared special light is superimposed on a subject image captured with normal light. In the second image data 102, the subject image by the green special light or the infrared special light is not so conspicuous because the exposure amount is small.

  Based on the first image data 101 and the second image data 102 thus acquired, the DIP 42 generates a normal light image obtained when the normal light image generation unit 51 illuminates with normal light according to the procedure shown in FIG. At the same time, the special light image generation unit 52 generates a special light image in which a specific part of the subject is appropriately emphasized.

  The procedure in which the DIP 42 generates the normal light image and the special light image is roughly divided into four steps (steps S10, S20, S30, and S40) performed substantially simultaneously. First, the DIP 42 extracts the blue component from the first image data 101 and the second image data 102, compares the pixel value of each B pixel, and calculates the pixel value of the normal light of each B pixel, A pixel value based on blue special light is calculated (step S10).

  Similarly, the DIP 42 extracts the green component from the first image data 101 and the second image data 102, compares the pixel value of each G pixel, and calculates the pixel value of each G pixel by the normal light. And a pixel value by the green special light are respectively calculated (step S20).

  Further, the DIP 42 extracts the red component from the first image data 101 and the second image data 102, compares the pixel value of each R pixel, and calculates the pixel value of each R pixel by the normal light, The pixel value by the infrared special light is calculated (step S30).

  Then, the DIP 42 generates a normal light image in which the pixel value of each RGB pixel becomes a pixel value obtained when illuminated with normal light from each pixel value calculated as described above, and specifies the subject. A special light image in which the region is emphasized is generated (step S40).

  As shown in FIG. 6A, the normal light image generation unit 51 calculates the pixel value of the normal light transmitted through the white light transmission regions 71 and 72 for each pixel of each RGB color (steps S11, S21, and S31). A normal light image is generated (step S41). On the other hand, as shown in FIG. 6B, the special light image generation unit 52 converts the pixel values of various special lights transmitted through the blue light transmission region 73, the green light transmission region 74, and the infrared light transmission region 76 into RGB colors. For each pixel (steps S12, S22, S32), and a special light image is generated (step S42). Further, the normal light image generation unit 51 and the special light image generation unit 52 operate in conjunction with each other so as to share the intermediately calculated data.

  More specifically, the normal light image generation unit 51 extracts a blue component from at least one of the first image data 101 or the second image data 102, compares and calculates the pixel value of each B pixel, and outputs the first white color. The pixel value of the B pixel by the normal light transmitted through the light transmission region 71 (or the second white light transmission region 72) is calculated (step S11). The special light image generation unit 52 uses the pixel value of the B pixel by the normal light calculated by the normal light image generation unit 51 to generate the blue light from the blue component of the first image data 101 or the second image data 102. A pixel value of the B pixel is calculated (step S12).

  Similarly, the normal light image generation unit 51 extracts the green component from at least one of the first image data 101 or the second image data 102, compares the pixel values of the G pixels, and calculates the first white light. The pixel value of the G pixel by the normal light transmitted through the transmission region 71 (or the second white light transmission region 72) is calculated (step S21). The special light image generation unit 52 uses the pixel value of the G pixel by the normal light calculated by the normal light image generation unit 51, and uses the green special light from the green component of the first image data 101 or the second image data 102. A pixel value of the G pixel is calculated (step S22).

  Further, the normal light image generation unit 51 extracts a red component from at least one of the first image data 101 or the second image data 102, compares and calculates the pixel value of each R pixel, and transmits the first white light. The pixel value of the R pixel by the normal light transmitted through the region 71 (or the second white light transmission region 72) is calculated (step S31). The special light image generation unit 52 uses the red light component of the first image data 101 or the second image data 102 as the red special light by using the pixel value of the R pixel by the normal light calculated by the normal light image generation unit 51. The pixel value of the R pixel due to the generated fluorescence is calculated (step S32).

  Thereafter, the normal light image generation unit 51 generates a normal light image using the calculated pixel value of each pixel based on the normal light (step S41). The special light image generation unit 52 generates a special light image by superimposing the calculated pixel values of various special lights on the normal light image at an appropriate ratio (step S42). Note that the special light image generation unit 52 generates special light images having different features such as different parts to be emphasized, according to the setting.

  Hereinafter, a more specific mode in which the DIP 42 generates the normal light image and the special light image by the normal light image generation unit 51 and the special light image generation unit 52 will be described.

  An example of the sensitivity of each RGB pixel of the image sensor 31 is shown in FIG. The sensitivity 106 of the B pixel is most sensitive to light in the vicinity of a wavelength of 450 nm and has sensitivity in a wavelength band 107 (hereinafter referred to as a blue wavelength band) of about 380 nm to 520 nm. The sensitivity 108 of the G pixel is most sensitive to light in the vicinity of a wavelength of 550 nm, and has sensitivity in a wavelength band 109 (hereinafter referred to as a green wavelength band) of about 470 nm to 650 nm. The sensitivity 110 of the R pixel is most sensitive to light in the vicinity of a wavelength of 630 nm, and has sensitivity in a wavelength band 111 (hereinafter referred to as a red wavelength band) of about 580 to 870 nm excluding the vicinity of 780 nm. Further, the R pixel is slightly more sensitive to infrared light near 830 nm than infrared light having a peripheral wavelength.

  FIG. 8A shows a graph of the amount of illumination (integrated value) and wavelength with which the subject is irradiated during the first imaging period 91. The distribution is a total of the irradiation amount 121 of blue special light and the irradiation amount 122 of normal light from the first white light transmission region 71. For this reason, the pixel value of each pixel of the first image data 101 includes values corresponding to the color wavelength bands 107, 109, and 111 shown in FIG. That is, when the illumination light shown in FIG. 8A is irradiated onto the observation site in the body cavity, the imaging element 31 receives the reflected light from the irradiated site and becomes the pixel value of each pixel. Yes. This pixel value includes a blue component and a white component corresponding to a surface blood vessel, a pit pattern, and the like suitable for observation with blue special light at the observation site.

  Similarly, a graph of the illumination light amount (integrated value) and wavelength irradiated on the subject in the second imaging period 96 is shown in FIG. 8B, and the green special light irradiation light amount 123 and the infrared special light irradiation light amount are shown. 124, the distribution amount of the normal light irradiation amount 125 by the second white light transmission region 72 is totaled. For this reason, the pixel values of the respective pixels of the second image data 102 include values corresponding to the portions of the respective color wavelength bands 107, 109, and 111 shown in FIG. That is, when the illumination light shown in FIG. 8B is irradiated onto the observation site in the body cavity, the imaging element 31 receives the reflected light from the irradiated portion and becomes the pixel value of each pixel. Yes. This pixel value includes a green component corresponding to redness and microvessels suitable for observing green special light at the observation site, a deep blood vessel that generates fluorescence by infrared special light, and a white component. Yes. As described above, since the imaging device 31 is not sensitive to infrared special light and sensitive to fluorescence excited by infrared special light, the pixel value of the R pixel of the second image data 102 is normal light. The total of the pixel value proportional to a part of the irradiation light amount 125 and the pixel value proportional to the fluorescence light amount 126. The amount of fluorescence 126 is, for example, smaller than the amount of normal light transmitted through the second white light transmission region 72.

  The DIP 42 extracts the components of each color from the video signal of the image sensor 31 and compares and calculates them to generate a normal light image and a special light image.

  As in the case of the illumination light quantity, as shown in FIG. 9A, the pixel value 131 of the B pixel in the first image data 101 is the normal pixel value 132 transmitted by the blue special light and the first white light transmission region 71. This is a total value with the pixel value 133 by light. In addition, the pixel value 134 of the B pixel of the second image data 102 corresponding to this is a pixel value 134 of normal light transmitted through the second white light transmission region 72 as shown in FIG. 9B. .

  Since the ratio of the amount of normal illumination light from the first white light transmission region and the amount of normal light from the second white light transmission region 72 is known, as shown in FIG. If the pixel value 134 of the pixel is calculated according to the ratio, it becomes the same as the pixel value 133 by the normal light transmitted through the first white light transmission region 71. For example, when the ratio of the illumination light amount of the normal light from the first white light transmission region 71 and the normal light from the second white light transmission region 72 is 1: 2, the pixel value 133 may be doubled. As shown in FIG. 9D, a pixel value 132 by blue special light is calculated by subtracting the pixel value 135 obtained by calculating the pixel value 134 from the pixel value 131 of the B pixel of the first image data 101. As the pixel value of the B pixel of the normal light image, which will be described later, the color balance is better than when the pixel value 133 is used, the pixel value 131 is used as it is.

  Similarly, as shown in FIG. 10A, the pixel value 141 of a G pixel in the first image data 101 is a pixel value based on normal light transmitted through the first white light transmission region 71. Further, as shown in FIG. 10B, the pixel value 142 of the G pixel in the second image data 102 corresponding to this corresponds to the pixel value 143 of normal light transmitted through the second white light transmission region 72 and green. This is the total value with the pixel value 144 by the special light.

  For this reason, as shown in FIG. 10C, the pixel value 141 of the G pixel of the first image data 101 is converted into the illumination light amount of normal light from the first white light transmission region 71 and normal light from the second white light transmission region 72. The pixel value 145 is calculated by calculating according to the ratio. As shown in FIG. 10D, the pixel value 144 by the green special light is calculated by subtracting the calculated pixel value 145 from the pixel value 142 of the G pixel of the second image data 102. The pixel value 141 is used as it is for the pixel value of the G pixel of the normal light image described later.

  Further, similarly, as shown in FIG. 11A, a pixel value 151 of an R pixel in the first image data 101 is a pixel value by normal light transmitted through the first white light transmission region 71. Further, as shown in FIG. 11B, the pixel value 152 of the R pixel in the second image data 102 corresponding to this corresponds to the pixel value 153 by the normal light transmitted through the second white light transmission region 72 and the red value. This is the sum of pixel values 154 due to fluorescence excited by external special light.

  For this reason, as shown in FIG. 11C, the pixel value 151 of the R pixel of the first image data 101 is changed to the normal light from the first white light transmission region 71 and the normal light from the second white light transmission region 72. The pixel value 155 is calculated by calculating according to the ratio. As shown in FIG. 11D, a pixel value 154 due to fluorescence excited by infrared special light is calculated by subtracting the calculated pixel value 155 from the pixel value 152 of the R pixel of the second image data 102. The

  These processes are represented visually as shown in FIGS. As shown in FIG. 12, the DIP 42 first extracts only the B pixel of the first image data 101 and generates first blue image data 161 that is a blue image component of the first image data 101 in the middle. At the same time, the DIP 42 extracts only the B pixel of the second image data 102 and generates second blue image data 162 that is a blue image component of the second image data 102 in the middle.

  Then, the normal light image generation unit 51 uses the first blue image data 161 generated in this way as image data similar to the case where the first blue image data 161 is captured only by the blue light included in the normal light (hereinafter referred to as normal blue image data). Output (step S11). Further, the special light image generation unit 52 converts the second blue image data 162 from the first blue image data 161 to the amount of illumination light of normal light from the first white light transmission region 71 and normal light from the second white light transmission region 72. By subtracting the one calculated in accordance with the ratio, the same image data 164 (hereinafter referred to as special blue image data) as when captured with only blue special light is generated (step S12).

  Similarly, as shown in FIG. 13, the DIP 42 extracts only the G pixel of the first image data 101 and generates first green image data 171 that is a green image component of the first image data 101 in the middle. . At the same time, the DIP 42 extracts only the G pixel of the second image data 102 and generates second green image data 172 that is a green image component of the second image data 102 in the middle.

  The normal light image generation unit 51 outputs the first green image data 171 generated in this way as image data similar to the case where the first green image data 171 is captured only with the green light included in the normal light (hereinafter referred to as normal green image data). (Step S21). Further, the special light image generation unit 52 uses the second green image data 172 to calculate the first green image data 171 for the illumination light amount of normal light from the first white light transmission region 71 and normal light from the second white light transmission region 72. By subtracting the one calculated in accordance with the ratio, the same image data 174 (hereinafter referred to as special green image data) as when captured with only the green special light is generated (step S22).

  Further, as shown in FIG. 14, the DIP 42 extracts only the R pixel of the first image data 101 and generates first red image data 181 that is a red image component of the first image data 101 in the middle. At the same time, the DIP 42 extracts only the R pixel of the second image data 102 and generates second red image data 182 that is a red image component of the second image data 102 in the middle.

  The normal light image generation unit 51 outputs the first red image data 181 generated in this way as the same image data (hereinafter referred to as normal red image data) as when captured by only red light included in normal light ( Step S31). Further, the special light image generation unit 52 converts the first red image data 181 from the second red image data 182 to the amount of illumination light of normal light from the first white light transmission region 71 and normal light from the second white light transmission region 72. By subtracting the one calculated according to the ratio, the same image data 184 (hereinafter referred to as special red image data) as when captured with only fluorescence excited by infrared special light is generated (step S32).

  When the various image data 161, 164, 171, 174, 181, 184 necessary for generating the normal light image and the special light image are generated in this way, the normal light image generating unit 51, as shown in FIG. The normal green image data 171 and the normal red image data 181 are combined to generate a full-color normal light image 191 (step S41).

  Further, as shown in FIGS. 16A to 16C, the special light image generation unit 52 sets the special blue image data 164, the special green image data 174, and the special red image data 184 as appropriate according to the settings. The special light images 192a to 192c are generated by superimposing on the normal light image 191 at a ratio (step S42). The special light image 192a is obtained by superimposing the special blue image data 164 on the normal light image 191, and the surface blood vessels and pit patterns are emphasized. The special light image 192b is obtained by superimposing the special green image data 174 on the normal light image 191, and emphasizes fine blood vessels, redness, and the like. The special light image 192c is obtained by superimposing the special red image data 184 on the normal light image 191 and emphasizes deep blood vessels and the like.

  As described above, some (or all) of the normal light images 191 and special light images 192a to 192c generated by the DIP 42 are displayed side by side on the monitor 26 as shown in FIG. The The surgeon performs diagnosis and treatment while comparatively observing these observation images. Of course, only the normal light image 191, only one of the special light images 192 a to 192 c, or one of the normal light image 191 and the special light images 192 a to 192 c may be displayed side by side.

  As described above, the electronic endoscope system 11 acquires the first image data 101 and the second image data 102 substantially simultaneously while modulating the illumination light by the rotary filter 62, and normal light is obtained from these image data 101 and 102. Observation images having different characteristics such as the image 191 and the special light images 192a to 192c are generated. For this reason, the electronic endoscope system 11 can acquire the normal light image 191 and the special light images 192a to 192c at the same time for a subject in the same state without being affected by the movement of the subject. Moreover, since the electronic endoscope system 11 can simultaneously acquire the normal light image 191 and the special light images 192a to 192c, these observation images can be compared and observed with each other. For this reason, in the electronic endoscope system 11, while being able to perform a test | inspection and a medical examination in a short time, the burden of a subject and an operator can be reduced. In addition, the accuracy of diagnosis is increased.

  Note that the amount of light transmitted through the first white light transmission region 71 and the second white light transmission region 72 can be arbitrarily determined. However, since there is a limit to the amount of signal charge that can be accumulated in each pixel of the image sensor 31, in order to prevent saturation of the signal charge of each pixel, normal light and special light are used as in the above-described embodiment. It is preferable that the amount of normal light irradiation be small in the imaging period in which the light is superimposed.

  In the above-described embodiment, the first section 81 of the rotary filter 62 is provided with the first white light transmission area 71, the blue light transmission area 73, and the first light shielding filter 77, and the second white section 83 is provided with the second white light. The light transmission region 72, the green light transmission region 74, the infrared light transmission region 76, and the second light shielding filter 78 are provided. The arrangement and types of the white light transmission region and the selective transmission region provided in the rotary filter 62 are as follows. Not exclusively.

  For example, like the rotary filter 201 shown in FIG. 18, the first partition 81 is provided with the first light blocking filter 77 and the first white light transmission region 202 (center angle θ3) along the rotation direction 82, and the second partition 83. In addition, a second light shielding filter 78, an infrared light transmission region 76, a green light transmission region 74, a blue light transmission region 73, and a second white light transmission region 203 (center angle θ4) are sequentially provided along the rotation direction 82. Also good. If the light shielding filters 77 and 78 are arranged to shield the illumination light from the light source 61 in synchronization with the readout timing of the image sensor 31, each selection in the first section 81 and the second section 83 is performed. The arrangement of the target transmission region and the white light transmission region may be interchanged. Further, in the same section, the white light transmission region, the blue light transmission region, and the white light transmission region may be arranged in this order, and the white light transmission region and the selective transmission region may be divided into two.

  In the above-described embodiment, the example in which the rotary filter 62 makes one rotation for two times of imaging has been described. However, the present invention is not limited thereto, and the rotary filter 62 makes one rotation for three or more times of imaging. May be. In this case, the normal light image 191 and the special light images 192a to 192c may be generated using all of the plurality of image data acquired during one rotation of the rotary filter 62, or the rotary filter 62 may be rotated once. The normal light image 191 and the special light images 192a to 192c may be generated using a part of the plurality of image data acquired in the meantime. However, it is preferable that the simultaneity of data is not lost.

  In the above-described embodiment, the wavelength band of light transmitted through the first white light transmission region 71 and the second white light transmission region 72 is 480 nm or more and 750 nm or less. The region may transmit light having a shorter wavelength, transmit light having a longer wavelength, or transmit a wider range of wavelength bands to include wavelength bands of various special lights.

  In the above-described embodiment, the white light transmission region, the selective transmission region, and the light shielding filter provided in the rotary filter 62 adjust the actual transmitted light amount by the product of the center angle and the transmittance. Not limited to this, the white light transmission regions 71 and 72, the blue light transmission region 73, the green light transmission region 74, and the infrared light transmission region 76 are all provided in the same central angle range, and only various transmittances are adjusted. You may make it adjust the effective irradiation light quantity of light. Conversely, the transmittance may be unified and only the area of the sector section may be changed.

  In the above-described embodiment, the transmittance and the amount of transmitted light of each of the blue light transmitting region 73, the green light transmitting region 74, and the infrared light transmitting region 76 are arbitrarily set within a range where a sufficient amount of light can be obtained for imaging. Can be determined.

  In the above-described embodiment, the light shielding filters 77 and 78 are provided so as to have a central angle ω that matches the readout periods 93 and 98. However, the present invention is not limited to this, and normal light and various special lights are sufficient. If the exposure amount can be obtained, a light shielding filter having a larger central angle range than the above-described embodiment may be provided. Further, when sufficient light shielding properties can be obtained by the mechanical shutter or the electronic shutter of the image sensor 31, the light shielding filters 77 and 78 may not be provided in the rotary filter 62.

  In the above-described embodiment, an example in which the rotary filter 62 is provided with the blue light transmission region 73, the green light transmission region 74, and the infrared light transmission region 76 as the selective transmission region that selectively transmits various special lights. Although described, the present invention is not limited to this, and the rotary filter 62 may be provided with a selective transmission region that selectively transmits other special light. For example, in order to observe thickening using autofluorescence such as collagen, a selective transmission region that selectively transmits special light in the vicinity of a wavelength of 600 nm may be provided in the rotary filter 62.

  In the above-described embodiment, a white high-intensity light source such as a xenon lamp is used alone as the light source 61, but a plurality of light sources may be used in combination as long as illumination light having a wavelength band necessary for imaging can be emitted. Alternatively, it may be used in a switchable manner. In addition to a gas lamp, a known light source such as an LED or a laser diode may be used. In addition, the light source 61 emits white illumination light, but a light source that realizes pseudo white using an overlap of the red-green cone visual sensitivity may be used.

  In the above-described embodiment, an example in which a depression or a ridge is imaged with blue special light has been described. However, the present invention is not limited thereto, and these structures can also be observed with light in the vicinity of a wavelength of 500 nm. You may make it observe these by taking out 134. FIG.

  In the above-described embodiment, when the special light images 192a to 192c are generated, the image data 164, 174, and 184 by various special lights are superimposed on the normal light image 191. However, the present invention is not limited to this, and various special lights are used. The special light images 192a to 192c may be generated by superimposing only the image data 164, 174, and 184 at an appropriate ratio.

  In the above-described embodiment, when the special light images 192a to 192c are generated, the image data 164, 174, and 184 based on various special lights are directly superimposed on the normal light image 191. However, the present invention is not limited to this. When superimposing the image data 164, 174, and 184, the components of these various special lights are converted into other colors and then superimposed on the normal light image 191, and the special light having a different color scheme from the above-described embodiment Images 192a to 192c may be generated.

  In the above-described embodiment, the special light images 192a to 192c are generated by superimposing the image data 164, 174, and 184 using various special lights on the normal light image 191, but the present invention is not limited to this, and the images using various special lights are used. By superimposing some of the data 164, 174, and 184 on the normal light image 191 at an appropriate ratio, a special light image in which a plurality of observation sites observed with various special lights are enhanced at the same time is generated. Also good.

  In the above-described embodiment, an example in which a full-color image is acquired by a so-called line-sequential method has been described. However, the present invention may be applied to an electronic endoscope system that acquires a full-color image by a frame-sequential method.

  In the above-described embodiment, the pixel value based on the normal light is calculated and the pixel value based on the special light is calculated using the normal light. However, the normal light is calculated from the first image data 101 and the second image data 102. The calculation procedure for calculating the pixel value based on the above and the pixel value based on the special light is not limited to the above-described embodiment. For example, the pixel value by special light may be calculated first, and the pixel value by normal light may be calculated using this.

  In the above-described embodiment, the electronic endoscope system 11 for observing the inside of the living body has been described as an example. However, the object to be observed is not limited to this, and the observation is performed from the inside without damaging the piping or the tunnel structure. The present invention can be suitably used for an apparatus or the like.

  In the above-described embodiment, the first white light transmission region 71 is a region that transmits all white light in the fan-shaped region. However, the first white light transmission region 71 is not limited to this, and the region that transmits white light is the first region. It may be a part of the fan-shaped area respectively assigned to the white light transmission area 71. For example, only the band-shaped portion along the outer periphery of the rotary filter 62 among the fan-shaped regions assigned to the first white light transmitting region 71 may transmit white light. The same applies to the second white light transmission region 72. As for the blue light transmission region 73, the green light transmission region 74, and the infrared light transmission region 76, the region that transmits the special light of each color is a part of the fan-shaped region assigned to each color light transmission region 73, 74, 76. It may be. Further, also for the first light shielding filter 77 and the second light shielding filter 78, the region where the illumination light is shielded may be a part of the sector-shaped region allocated thereto.

  In the above-described embodiment, an example in which RGB color filters are arranged for each pixel in the image sensor 31 and the components for each RGB basic color are extracted when the DIP 42 generates an observation image has been described. In the element 31, complementary color filters of three colors of yellow, cyan, and magenta (or four colors obtained by adding green) are arranged for each pixel. When the DIP 42 generates an observation image, yellow, cyan, and magenta Each color component of (, green) may be extracted and compared and calculated.

It is an external view which shows the structure of an electronic endoscope system. It is a block diagram which shows the electrical and optical structure of an electronic endoscope system. It is explanatory drawing which shows the structure of a rotary filter. It is explanatory drawing which shows the drive timing of an image pick-up element and a rotary filter. It is explanatory drawing which shows the image data acquired with an electronic endoscope system. It is a flowchart which shows the procedure which produces | generates an observation image from the acquired image data. It is a graph which shows the sensitivity of the image sensor with respect to a wavelength. It is explanatory drawing which shows the light quantity of the illumination light in each imaging period. It is explanatory drawing which shows a mode that the pixel value by normal light and the pixel value by blue special light are each calculated from the pixel value of B pixel of 1st image data and 2nd image data. It is explanatory drawing which shows a mode that the pixel value by normal light and the pixel value by green special light are each calculated from the pixel value of G pixel of 1st image data and 2nd image data. It is explanatory drawing which shows a mode that the pixel value by normal light and the pixel value by fluorescence excited by infrared special light are each calculated from the pixel value of R pixel of 1st image data and 2nd image data. It is explanatory drawing which shows a mode that DIP produces | generates normal blue image data and special blue image data in the middle. It is explanatory drawing which shows a mode that DIP produces | generates normal green image data and special green image data in the middle. It is explanatory drawing which shows a mode that DIP produces | generates normal red image data and special red image data in the middle. It is explanatory drawing which shows a mode that a normal light image generation part produces | generates a full color normal light image. It is explanatory drawing which shows a mode that a special light image generation part produces | generates a special light image. It is explanatory drawing which shows a mode that a normal light image and a special light image are simultaneously displayed on a monitor. It is explanatory drawing which shows the modification of a rotary filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Electronic endoscope system 12 Electronic endoscope 13 Processor apparatus 14 Light source apparatus 31 Imaging element 33, 41, 63 CPU
42 DIP
43 DSP
DESCRIPTION OF SYMBOLS 51 Normal light image generation part 52 Special light image generation part 61 Light source 62, 201 Rotary filter 71,202 1st white light transmission area 72,203 2nd white light transmission area 73 Blue light transmission area 74 Green light transmission area 76 Infrared Light transmission region 77 First light shielding filter 78 Second light shielding filter 101 First image data 102 Second image data 161 First blue image data 162 Second blue image data 163 Normal blue image data 164 Special blue image data 171 First green image Data 172 Second green image data 173 Normal green image data 174 Special green image data 181 First red image data 182 Second red image data 183 Normal red image data 184 Special red image data 191 Normal light image 192 Special light image

Claims (6)

Imaging means for imaging the subject by photoelectrically converting light from the subject;
A light source that generates illumination light to irradiate the subject;
At least one of the fan-shaped sections of a fan-shaped section having a predetermined central angle, which is rotatably arranged in front of the light source, rotates in synchronization with a plurality of times of imaging by the imaging means, and corresponds to one imaging by the imaging means. The section has a selective transmission region that selectively transmits a wavelength band component narrower than the wavelength band to which the pixel of the image sensor is sensitive, centered on a certain wavelength, and all the fan-shaped sections have a wavelength band of white light. A rotary filter having a white light transmission region that transmits the component;
Observation image generation means for generating a plurality of observation images having different characteristics from image data captured while the rotary filter rotates,
An electronic endoscope system comprising:   The white light includes light having a wavelength band longer than 500 nm and shorter than 750 nm, light having a wavelength band shorter than 450 nm is 1/10 or less of the amount of light having a wavelength of 500 nm, and light having a wavelength band longer than 780 nm is 750 nm. The electronic endoscope system according to claim 1, wherein the electronic endoscope system is 1/10 or less of an amount of light having a wavelength of 1.   3. The electronic endoscope system according to claim 1, wherein the light transmitted through the selective transmission region has a central wavelength in the vicinity of 450, 500, 550, 600, or 780 nm. .   The electronic endoscope according to any one of claims 1 to 3, wherein the rotary filter has a light-shielding region that shields the illumination light corresponding to a charge reading period of the imaging unit for each of the fan-shaped sections. Mirror system.   The observation image generation means extracts color components from each of the plurality of image data, and calculates intermediate image data obtained when imaging is performed by irradiating illumination light transmitted through the selective transmission region. The electronic endoscope system according to any one of claims 1 to 4.   6. The electronic endoscope system according to claim 5, wherein the observation image generating unit generates an enhanced image in which a predetermined part of the subject is enhanced from the intermediate image data.

Images