JP4654353B2 - Endoscope system - Google Patents

Description

  The present invention relates to an endoscope system that observes the inside of a body cavity by irradiating light into the body cavity through a light guide provided in the endoscope.

  As is well known, when a biological tissue is irradiated with light of a specific wavelength, it is excited and emits fluorescence. In addition, an abnormal living tissue in which a lesion such as a tumor or cancer has occurred emits weaker fluorescence than a normal living tissue. In recent years, endoscope systems have been developed that detect abnormalities occurring in living tissue in a body cavity by utilizing this phenomenon.

  Such an endoscope system includes an endoscope, a light source processor device (a combination of a light source device and an image processing processor device), and a display device.

  The endoscope includes a light guide that guides illumination light to a distal end of an insertion portion that is inserted into a body cavity, and an imaging element that images the inside of the body cavity and generates an image signal.

  The light source processor device is a mode in which only white light is incident on the light guide (hereinafter referred to as “normal observation mode”) and a mode in which white light and excitation light (ultraviolet light) are alternately incident on the light guide (hereinafter referred to as “fluorescence observation”). Mode ”), and the light emitted to the living tissue can be incident on the light guide, and the image output from the endoscope in the normal observation mode and the fluorescence observation mode. The image processing content for the signal is changed. Hereinafter, image processing contents in these observation modes will be described.

  In the normal observation mode, white light is irradiated from the distal end of the insertion portion of the endoscope, and a normal observation image by reflected light from the body cavity wall illuminated with the white light is displayed on the display device.

  In the fluorescence observation mode, white light and excitation light are alternately irradiated from the distal end of the insertion portion of the endoscope. Then, an image signal obtained when white light is irradiated is used as a reference image signal, and an image signal obtained when excitation light is emitted is used as a fluorescence image signal. A portion that is brightly displayed but is darkly displayed in the image based on the fluorescence image signal is extracted as a lesion by the light source processor device, and a fluorescence observation image showing the extracted lesion is displayed on the display device.

In the light source processor apparatus employed in such a fluorescence observation electronic endoscope system, in order to match the irradiation ranges of the white light and the excitation light, the white light and the excitation are supplied to one light guide passed through the endoscope. A configuration in which light is incident may be employed. In this case, since the intensity of the excitation light is weaker than the intensity of the white light in a general light source device, white light is generated inside the light source processor device so as not to cause a loss in the excitation light incident on the light guide. A condensing lens for converging the excitation light is disposed on the optical path in which the optical path of the light and the optical path of the excitation light coincide with each other so as to have a diameter smaller than the diameter of the light guide. Patent Document 1 discloses an endoscope apparatus that can converge light to a diameter smaller than the diameter of a light guide.
JP 05-130973 A

  By the way, in a general light guide, in order to transmit light energy instead of an image, the positional relationship between optical fibers at the distal end side of the light guide with respect to the positional relationship between optical fibers at the proximal end side of the light guide. Designed to be random.

  Therefore, even if light is converged on a part of the light guide base end face, the light emitted from the front end of the light guide may not be emitted in the same shape as the light converged on the light guide base end face. obtain. For example, when excitation light is incident on a part of the base end face of the light guide, unevenness occurs in the excitation light emitted from the tip of the light guide, and the intensity distribution of the excitation light on the living tissue is extremely biased. There is a fear (for example, only a part of the entire irradiation range may become dark). Thus, when the intensity distribution of the excitation light emitted from the light guide is biased, even if the living tissue is a normal part, the intensity distribution of the fluorescence emitted from the living tissue is also biased (partially Is dark). Therefore, in this case, even if the portion to be observed is a normal portion, there is a possibility that a portion where the intensity of the irradiated excitation light is weak is determined as a lesion portion.

  Therefore, the problem of the present invention is that the intensity distribution of light emitted from the front end of the light guide is adopted even when a configuration in which light is converged to a diameter smaller than the diameter of the light guide on the light guide base end surface is adopted. An object of the present invention is to provide an endoscope system in which extreme bias does not occur.

  An endoscope system according to the present invention devised to solve the above problems is an endoscope system including an endoscope and a light source device, and the endoscope is incident on a proximal end side. A light guide that emits a light beam from the tip side, an objective optical system that forms an image of an observation object, and an imaging device that captures an image formed by the objective optical system and outputs an image signal; The light source device includes a white light source unit that emits white light as parallel light, an excitation light source unit that emits excitation light for exciting biological tissue as parallel light, and white light emitted from the white light source unit. A condensing optical system for converging the light traveling on the light path toward the base end side of the light guide, an optical path of white light emitted from the white light source unit, and an excitation emitted from the excitation light source unit Arranged in a position where the light path of light overlaps, An optical path synthesis element that transmits the white light and the excitation light toward the condensing optical system by transmitting light and reflecting the excitation light, and an optical path synthesis element rotation that changes the direction of the optical path synthesis element And a control unit that controls the optical path synthesizing element rotating means so that the intensity distribution of the excitation light emitted from the tip of the light guide is constant in the imaging range of the imaging element. .

  If comprised in this way, white light and excitation light will inject into a condensing optical system. At this time, if there is a bias in the intensity distribution of the excitation light emitted from the tip of the light guide in the imaging range of the imaging element, the control unit changes the direction of the optical path combining element to change the base of the light guide. The spot position of the excitation light incident on the end side is changed. In this way, the spot position of the excitation light incident on the light guide is optimized by the control unit (so that the intensity distribution of the excitation light emitted from the tip of the light guide is constant in the imaging range by the imaging device). Therefore, even if the endoscope system is designed so that the spot diameter of the excitation light converged by the condensing optical system is smaller than the diameter of the light guide, it is emitted from the tip of the light guide in the imaging range by the imaging device. An extreme bias does not occur in the intensity distribution of the excitation light.

  The optical path synthesizing element rotating means may rotate the optical path synthesizing element around two rotation axes that intersect each other.

  In addition, the endoscope according to the present invention further includes a storage device that stores an identification number for identifying the endoscope, and the control unit is configured to capture the identification number in the imaging range of the imaging element for each identification number. A storage unit for storing rotation angles of the respective rotation axes of the optical path combining element in which the intensity distribution of the excitation light irradiated from the tip of the light guide corresponding to the identification number is constant; When the mirror and the light source device are connected, the rotation angle of the optical path synthesis element corresponding to the identification number of the endoscope is read from the storage unit, and the rotation angle of the optical path synthesis element is the read rotation angle The optical path synthesizing element rotating means may be controlled so as to be.

  In addition, the control unit according to the present invention may divide an image captured by the imaging element into a plurality of regions while the excitation light emitted from the light guide is irradiated on the fluorescent plate that emits fluorescence when the excitation light is irradiated. It is also possible to divide and compare the brightness of each region and control the optical path synthesizing element rotating means so that the brightness of each region is constant.

  According to the present invention, even when a configuration in which light is converged to a diameter smaller than the diameter of the light guide on the light guide base end surface is extremely biased to the intensity distribution of light emitted from the tip of the light guide. It is possible to provide an endoscope system in which no occurs.

  Next, modes for carrying out the present invention will be described based on the attached drawings.

  FIG. 1 is an external view of an endoscope system according to an embodiment of the present invention. As shown in FIG. 1, the endoscope system includes a fluorescence observation endoscope 10, a light source processor device 20, and a monitor 60.

  The fluorescence observation endoscope 10 is obtained by adding a modification for fluorescence observation to a normal electronic endoscope. The insertion portion 10a is formed to be elongated in order to be inserted into a body cavity, and the distal end of the insertion portion 10a. An operation unit 10b having an angle knob for bending the portion, a light guide flexible tube 10c for connecting the operation unit 10b and the light source processor device 20, and a base end of the light guide flexible tube 10c A provided connector 10d is provided.

  On the front panel of the housing of the light source processor device 20, a key switch 22 for controlling on / off of a main power source of an excitation light source 204, which will be described later, a switch for designating a normal observation mode, a switch for designating a fluorescence observation mode, A switch panel 23 on which various operation switches including a switch for designating the start of the adjustment operation are arranged, and a socket 24 to which the connector 10d of the fluorescence observation endoscope 10 is connected.

  FIG. 2 is a schematic diagram showing the internal configuration of the fluorescence observation endoscope 10 and the light source processor device 20. Hereinafter, detailed configurations of the fluorescence observation endoscope 10 and the light source processor device 20 will be sequentially described with reference to FIG.

  As shown in FIG. 2, a light distribution lens 11 and an objective lens 12 (corresponding to an objective optical system) are provided on the distal end surface of the insertion portion 10 a of the fluorescence observation endoscope 10. And inside this insertion part 10a, it is provided between the imaging element 13 which image | photographs the image of the to-be-photographed object formed with the objective lens 12, and converts it into an image signal, and the objective lens 12 and the imaging element 13, An excitation light cut filter 14 for removing a wavelength component of excitation light emitted from an excitation light source 204 described later is incorporated.

  As shown in FIG. 2, a metal tube 19 that protrudes vertically is provided on the end surface of the connector 10 d of the fluorescence observation endoscope 10.

  Further, inside the fluorescence observation endoscope 10, a signal cable 18 for transmitting an image signal output from the image pickup device 13 passes through the insertion portion 10a, the operation portion 10b, and the light guide flexible tube 10c. Then, it is connected to a connector pin (not shown) formed on the end face of the connector 10d. In addition, a memory (not shown) (not shown) is connected to the signal cable 18 inside the fluorescence observation endoscope 10. In this memory, an identification number for identifying the fluorescence observation endoscope 10 is stored.

  In parallel with the signal cable 18, the light guide 16 is passed through the insertion portion 10a, the operation portion 10b, and the light guide flexible tube 10c. Note that the distal end of the light guide 16 faces the light distribution lens 11 in the distal end portion of the insertion portion 10a, and the proximal end thereof is inserted and fixed in the metal tube 19 in the connector 10d.

  FIG. 6 is an explanatory view showing the base end face of the light guide 16. As shown in FIG. 6, the light guide 16 is composed of a plurality of bundled optical fibers and has a diameter substantially equal to the inner diameter of the metal tube 19. The light guide 16 transmits the energy of light, not an image, and the positions of the optical fibers on the distal end side of the light guide 16 with respect to the positional relationship between the optical fibers on the proximal end side of the light guide 16. Designed to make the relationship random. Specifically, the light guide 16 twists the entire bundle of optical fibers so that the amount of twist of the optical fiber increases as the distance from the central axis of the light guide 16 increases (the closer to the outer periphery of the light guide 16). (So that the displacement of the position of the optical fiber on the distal end side with respect to the position of the optical fiber on the proximal end side becomes large).

  In FIG. 6, a circular hatched area 80 drawn inside the metal tube 19 indicates excitation light converged by a condenser lens 203 described later. As shown in FIG. 6, when the excitation light is incident on a part of the base end face of the light guide 16, even if the excitation light incident on the base end face has a circular shape, Since the emission position of the excitation light incident on the fiber is greatly shifted, the shape of the excitation light emitted from the tip of the light guide 16 may not be circular (the intensity distribution of the excitation light may be extremely biased). obtain.

  Next, the light source processor device 20 will be described in detail. The light source processor device 20 selectively introduces white light and excitation light into the proximal end surface of the light guide 16 of the fluorescence observation endoscope 10 and receives it from the image sensor 13 through the terminal of the connector 10d of the fluorescence observation endoscope 10. This is a device for generating a video signal by performing image processing on the processed image signal and outputting it to the monitor 60.

  The socket 24 of the light source processor device 20 is formed with a through hole into which the metal tube 19 in the connector 10d of the fluorescence observation endoscope 10 is inserted from the outer surface. The through hole of the socket 24 communicates with the internal space of the light source processor device 20.

  The light source processor device 20 is directed toward the socket 24 on an extension line of the central axis of the through hole of the socket 24 (that is, the central axis of the light guide 16 in the metal tube 19 inserted into the through hole of the socket 24). In order, a white light source 201 that emits white light as parallel light (corresponding to a white light source unit), a rotation shielding plate 206 that passes or blocks a light beam emitted from the white light source 201, and a rotation shielding plate 206 are provided. A condensing lens 203 (corresponding to a condensing optical system) for converging the light flux that has passed and entering the light guide 16 is provided.

  The light source processor device 20 further includes an excitation light source 204 that emits excitation light as diverging light, and a collimator lens 205 that converts the excitation light emitted from the excitation light source 204 into parallel light (excitation). The light source 204 and the collimating lens 205 correspond to an excitation light source unit). The optical path of the excitation light that has passed through the collimator lens 205 and the optical path of the white light that has passed through the rotation shielding plate 206 intersect perpendicularly.

  The light source processor device 20 further includes a dichroic mirror 300 at a position where the optical path of the excitation light that has passed through the collimator lens 205 and the optical path of the white light that has passed through the rotation shielding plate 206 intersect perpendicularly. Hereinafter, each part will be described in detail.

  The white light source 201 emits white light having a wavelength component in the entire visible band. The white light source 201 includes an infrared filter that removes light in the infrared region in front of the white light exit. Therefore, the infrared light component is removed from the white light emitted from the white light source 201.

  The rotation shielding plate 206 is a disc in which only one substantially semicircular opening is formed, and the center of the arc of the opening coincides with the center of the outer circumference of the rotation shielding plate 206. The center of the rotation shielding plate 206 is fixed to the tip of a drive shaft of a motor (not shown). When driven by a motor (not shown), the rotation shielding plate 206 rotates about the drive shaft. When the rotation shielding plate 206 is rotated, the opening of the rotation shielding plate 206 and the portion other than the opening of the rotation shielding plate 206 are alternately arranged on the light beam emitted from the white light source 201. . For this reason, the rotation shielding plate 206 can switch between a state in which white light from the white light source 201 passes and a state in which it is blocked depending on the rotation position.

  The excitation light source 204 is a laser diode that emits excitation light for exciting a living tissue to generate fluorescence. The wavelength of the excitation light is, for example, ultraviolet light.

  The dichroic mirror 300 is an optical element that transmits white light and reflects excitation light. In FIG. 2, the dichroic mirror 300 is inclined 45 ° with respect to the white light beam emitted from the white light source 201 and is also inclined 45 ° with respect to the optical axis of the collimating lens 205. It is shown. In this case, the white light that has passed through the rotation shielding plate 206 passes through the dichroic mirror 300, and the excitation light emitted from the collimating lens 205 is reflected at a right angle by the dichroic mirror 300, so that it is the same as the white light. In the same direction as the traveling direction of the white light. Therefore, the dichroic mirror 300 functions as an optical path synthesis element.

  The dichroic mirror 300 is held by a dichroic mirror rotating device 30 (corresponding to an optical path combining element rotating unit). Hereinafter, the configuration of the dichroic mirror rotating device 30 will be described in detail with reference to FIG.

  FIG. 3 is a perspective view of the dichroic mirror 300 and the dichroic mirror rotating device 30. As shown in FIG. 3, the dichroic mirror rotating device 30 includes a mirror holding frame 321, a mirror rotating motor 317, and a mirror holding frame rotating motor 325.

  The mirror holding frame 321 is composed of a rectangular plate-like frame plate 321a and rectangular plate-like frame plates 321b and 321c that respectively hang down from both short edges of the frame plate 321a. The frame plates 321b and 321c have substantially the same shape and face each other in parallel. Further, in the vicinity of the ends of the frame plates 321b and 321c (on the side away from the frame plate 321a), through holes that penetrate the frame plates 321b and 321c vertically and coaxially are formed, respectively.

  The mirror rotation shafts 311 and 312 pass through the through holes of the frame plates 321b and 321c, respectively, so as to be freely rotatable. Mirror holding portions 313 and 314 are formed at the tip ends of the mirror rotation shafts 311 and 312 protruding inside the mirror holding frame 321, respectively. These mirror holding portions 313 and 314 hold the dichroic mirror 300 by sandwiching a part of the side edge of the dichroic mirror 300, for example.

  Further, a mirror rotation shaft pinion 315 is fixed to a tip of the mirror rotation shaft 311 that protrudes outside the mirror holding frame 321. The mirror rotation shaft pinion 315 is engaged with a gear 316, and the gear 316 is fixed to the rotation shaft of the mirror rotation motor 317. Although not shown in FIG. 3, the mirror rotation motor 317 is fixed integrally with the mirror holding frame 321. Therefore, by rotating the mirror rotation motor 317, the dichroic mirror 300 can be rotated about the mirror rotation shafts 311 and 312 as rotation shafts. Note that a pulse motor is employed as the mirror rotation motor 317.

  The mirror holding frame rotation shaft 322 is fixed to the outer surface of the frame plate 321a so that the axial direction is perpendicular to the frame plate 321a. A mirror holding frame rotation shaft pinion 323 is integrally fixed to the mirror holding frame rotation shaft 322. A gear 324 meshes with the mirror holding frame rotation shaft pinion 323, and the gear 324 is fixed to the rotation shaft of the mirror holding frame rotation motor 325. In FIG. 3, the mirror holding frame rotating shaft 322 shows only the length from the frame plate 321a to the mirror holding frame rotating shaft pinion 323, but in reality, the mirror holding frame rotating shaft 322 rotates the mirror holding frame. The shaft pinion 323 extends beyond the shaft pinion 323, and the tip of the shaft pinion 323 is rotatably held in the housing of the light source processor device 20. Although not shown in FIG. 3, the mirror holding frame rotation motor 325 is fixed to the housing of the light source processor device 20. Therefore, by rotating the mirror holding frame rotation motor 325, the mirror holding frame 321 can be rotated about the mirror holding frame rotation shaft 322 as a rotation axis. In addition, a pulse motor is employed as the mirror holding frame rotation motor 325.

  With the above configuration, the dichroic mirror 300 can rotate around two rotation axes that intersect perpendicularly to each other, and thus can face all directions. Therefore, when the excitation light transmitted through the collimator lens 205 enters the dichroic mirror 300, the direction of the reflected light of the excitation light can be changed by changing the direction of the dichroic mirror 300.

  The dichroic mirror rotating device 30 is provided with an initial state detecting device (not shown). In this initial state detection device, the frame plates 321a, 321b, and 321c are parallel to the white light beam emitted from the white light source 201, and the dichroic mirror 300 is oriented in a direction that reflects the excitation light toward the condenser lens 203. A state inclined by 45 ° with respect to the optical axis of the collimating lens 205 is detected as an initial state. When the initial state is detected, the initial state detection device transmits information indicating the initial state to the system control circuit 214.

  The condensing lens 203 is a lens having a positive power for converging parallel light. The condensing lens 203 refracts excitation light more than white light.

  In the present embodiment, the diameter of the white light emitted from the white light source 201 is set so that the diameter of the white light converged on the base end surface of the light guide 16 is larger than the diameter of the light guide 16. ing. In this case, a part of the light emitted from the white light source 201 does not enter the light guide 16 (although there is a loss), but the intensity of the white light emitted from the white light source 201 Therefore, even if there is some loss, the white light emitted from the tip of the light guide 16 has sufficient intensity to be used as illumination light.

  In the present embodiment, the diameter of the excitation light emitted from the collimator lens 205 is set so that the diameter of the excitation light converged on the base end surface of the light guide 16 is smaller than the diameter of the light guide 16. Yes. Therefore, all the excitation light emitted from the collimating lens 205 can be incident on the light guide 16. FIG. 2 shows that the diameter of the white light beam emitted from the white light source 201 is larger than the diameter of the excitation light beam emitted from the collimating lens 205. Since the optical lens 203 refracts the excitation light more than the white light, when the diameter of the white light incident on the light guide 16 and the diameter of the excitation light can be set as described above, the light lens 203 is emitted from the white light source 201. The diameter of the white light beam and the diameter of the excitation light beam emitted from the collimator lens 205 may be the same.

  The light source processor device 20 further includes a power supply circuit 211, a mirror driver circuit 212, and a system control circuit 214 (corresponding to a control unit) in order to operate the configuration described above. The light source processor device 20 further includes a video signal processing circuit 213 that performs image processing on the image signal generated by the imaging element 13.

  The power supply circuit 211 is a circuit for supplying power to the white light source 201.

  The mirror driver circuit 212 is a circuit for controlling the orientation of the dichroic mirror 300. When the rotation angle of the dichroic mirror 300 and the rotation angle of the mirror holding frame 321 are received from the system control circuit 214, the mirror driver circuit 212 is based on these rotation angles. The mirror rotation motor 317 and the mirror holding frame rotation motor 325 are controlled.

  The video signal processing circuit 213 is electrically connected to the system control circuit 214 and the monitor 60. When the fluorescence observation endoscope 10 and the light source processor device 20 are connected, they are electrically connected to the image sensor 13 via the signal cable 18 of the fluorescence observation endoscope 10. The video signal processing circuit 213 converts the image signal generated by the image sensor 13 into a video signal, and displays a video based on the video signal on the monitor 60. In addition, the video signal processing circuit 213 transmits the image signal generated by the image sensor 13 to the system control circuit 214.

  The system control circuit 214 is a controller for controlling the entire light source processor device 20, and includes a switch panel 23 (not shown in FIG. 2) provided on the front panel of the housing of the light source processor device 20, and a rotation shielding plate. The motor 206, the power supply circuit 211, the mirror driver circuit 212, the video signal processing circuit 213, and the excitation light source 204 are electrically connected. Although not shown in FIG. 2, when the fluorescence observation endoscope 10 and the light source processor device 20 are connected, the system control circuit 214 connects the memory of the fluorescence observation endoscope 10 with the electric power via the signal cable 18. Connect. The system control circuit 214 controls each component of the light source processor device 20 based on an operation signal generated by operating the switch panel 23. Further, the system control circuit 214 associates and registers the identification number of the fluorescence observation endoscope 10 that has been connected to the light source processor device 20 in the past, the rotation angle of the dichroic mirror 300, and the rotation angle of the mirror rotation frame 321. A storage unit.

  Hereinafter, the operation after the fluorescence observation endoscope 10 is connected to the light source processor device 20 will be described with reference to the flowchart of FIG.

  In the first S001, when the system control circuit 214 detects that the fluorescence observation endoscope 10 is connected to the light source processor device 20, the fluorescence observation from the memory provided in the fluorescence observation endoscope 10 is performed. The identification number of the endoscope 10 is read. At this time, if the system control circuit 214 has not detected that the dichroic mirror rotating device 30 is in the initial state, the system control circuit 214 transmits an instruction to set the dichroic mirror rotating device 30 to the initial state to the mirror driver circuit 212. .

  In next step S002, the system control circuit 214 determines whether or not the read identification number is registered in the storage unit of the system control circuit 214. When the system control circuit 214 determines that the identification number is not registered in the storage unit of the system control circuit 214, the process proceeds to S003. When the system control circuit 214 determines that the identification number is registered in the storage unit of the system control circuit 214, the process proceeds to S021.

  In step S <b> 003, the system control circuit 214 sends an instruction to display on the monitor 60 a screen indicating that the fluorescence observation endoscope 10 connected to the light source processor 20 device has not been adjusted, to the video signal processing circuit 213. Then, the system control circuit 214 waits until a switch for instructing the start of the adjustment operation is operated.

  An operator who sees the monitor 60 on which a screen indicating that the fluorescence observation endoscope 10 has not been adjusted is displayed, fixes the distal end of the insertion portion 10a of the fluorescence observation endoscope 10 to an adjustment jig. The adjustment jig has a fluorescent plate in which a coating material that emits fluorescence when irradiated with excitation light emitted from the excitation light source 204 is uniformly applied to the entire surface. When the insertion portion 10a is fixed to an adjustment jig, the tip of the insertion portion 10a is designed to face the surface of the fluorescent screen. As the fluorescent paint, a paint whose fluorescence intensity changes in proportion to the intensity of the irradiated excitation light is used. Therefore, if there is no unevenness in the excitation light irradiated to the fluorescent plate, fluorescent light having a uniform intensity is emitted from the irradiation range.

  The surgeon operates the switch for instructing the start of the adjustment operation after fixing the distal end of the insertion portion 10a of the fluorescence observation endoscope 10 to the adjustment jig. Then, the system control circuit 214 rotates the rotation shielding plate 206 to the rotation position where the white light is shielded, and then advances the process to S004.

  In S004, the system control circuit 214 controls the excitation light source 204 to irradiate the fluorescent plate with the excitation light.

  In next step S005, the system control circuit 214 performs image confirmation processing. In this image confirmation process, the system control circuit 214 divides the fluorescent image of the fluorescent screen imaged by the imaging device 13 into a plurality of areas, and calculates the brightness in each area. Hereinafter, this processing will be specifically described with reference to FIG.

  FIG. 5 is an explanatory diagram showing an example of image division. As shown in FIG. 5, in the present embodiment, the image 50 is divided into nine areas of a first area 51 to a ninth area 59. Then, the system control circuit 214 calculates the brightness for each area. Note that the brightness calculated for each region may be an average value of luminance values of all pixels in the region, or may be a total value of luminance values of all pixels in the region. When the brightness for each area is calculated, the system control circuit 214 advances the processing to the next S006.

  In S006, the system control circuit 214 compares the brightness for each area calculated in S005 to check whether there is unevenness in the brightness of the image formed by the image signal (the illumination light is balanced). Whether or not) is determined.

  Specifically, the system control circuit 214 executes the calculation shown in the following equation (1) to obtain the image balance. Note that the degree of balance calculated by the equation (1) is a numerical value indicating the unevenness of brightness in the entire image. The smaller the value, the less the unevenness of brightness. Will be zero).

| (Brightness of the first region 51 + brightness of the ninth region 59) − (brightness of the seventh region 57 + brightness of the third region 53) | + | (brightness of the second region 52 + eighth (Brightness of region 58) − (Brightness of fourth region 54 + Brightness of sixth region 56) | = Equilibrium (1)
By the way, in the expression (1), the brightness of the fifth region 55 is not used for the calculation. As described above, the light guide 16 is designed so that the positional relationship between the optical fibers is shifted as the distance from the central axis increases. Therefore, in the vicinity of the central axis of the light guide 16, There is little deviation between the positional relationship and the positional relationship between the optical fibers on the distal end side. Therefore, the excitation light that has entered the vicinity of the central axis on the base end surface of the light guide 16 is emitted from the tip of the light guide 16 while maintaining the positional relationship at the time of incidence. When the endoscope system is actually manufactured, the diameter of the excitation light converged on the base end face of the light guide 16 is as large as possible (however, the light guide 16 is used) so that the excitation light is incident on as many optical fibers as possible. (In a range smaller than the diameter). Therefore, when the endoscope system is actually used, when all the excitation light is incident on the proximal end surface of the light guide 16, the excitation light is always incident near the center of the proximal end surface of the light guide 16. Therefore, the brightness of the fifth region 55 is always constant. Therefore, it is not necessary to use the brightness of the fifth region 55 when calculating the uneven brightness in the entire image.

  In S006, when the system control circuit 214 determines that the brightness of the image is uneven (for example, when the equilibrium value is not zero), the process proceeds to S007. In S006, when the system control circuit 214 determines that there is no unevenness in the brightness of the image (for example, when the equilibrium value is zero), the process proceeds from S006 to S019.

  Here, in order to facilitate the explanation of the operations of the dichroic mirror 300 and the mirror holding frame 321 in S007 to S016, the rotation directions of the dichroic mirror 300 and the mirror holding frame 321 are defined. Specifically, in FIG. 3, when excitation light is incident on the dichroic mirror 300 from the lower side of the drawing, the rotation direction in which the dichroic mirror 300 is rotated clockwise as viewed from the mirror rotation axis pinion 315 side is expressed as “mirror "Angle upward direction". The rotation direction in which the dichroic mirror 300 is rotated in the direction opposite to the “mirror angle upward direction” is defined as “mirror angle downward direction”. Further, in FIG. 3, when excitation light is incident on the dichroic mirror 300 from the lower side of the drawing, the rotation direction in which the mirror holding frame 321 is rotated clockwise as viewed from the mirror holding frame rotation shaft pinion 323 side is expressed as “mirror "Angle right direction". Further, the rotation direction in which the mirror holding frame 321 is rotated in the direction opposite to the “mirror angle right direction” is defined as “mirror angle left direction”.

  In S007, the system control circuit 214 transmits to the mirror driver circuit 212 an instruction to rotate the dichroic mirror 300 by a predetermined angle (for example, angle 1 second) upward in the mirror angle. Then, the mirror driver circuit 212 controls the mirror rotation motor 317 to rotate the dichroic mirror 300 by a predetermined angle upward in the mirror angle.

  In the next S008, the system control circuit 214 performs the same image confirmation process as in S005, and advances the process to S009.

  In S009, the system control circuit 214 calculates the degree of balance after rotating the dichroic mirror 300 in the upward direction of the mirror angle. Then, the system control circuit 214 compares the balance after the rotation with the balance just before the rotation, and determines whether or not the balance is reduced by this rotation (the direction in which the balance of the illumination light is matched). Determine. At this time, if the system control circuit 214 determines that the degree of balance has decreased, the system control circuit 214 returns the process to S007 and repeats the processes of S007 to S009. If the system control circuit 214 determines that the balance has increased due to this rotation, or if it has determined that the balance has not changed, the process proceeds to S010.

  In S010, the system control circuit 214 transmits an instruction for rotating the dichroic mirror 300 downward by a predetermined angle (for example, an angle of 1 second) to the mirror driver circuit 212. Then, the mirror driver circuit 212 controls the mirror rotation motor 317 to rotate the dichroic mirror 300 by a predetermined angle downward in the mirror angle.

  In the next S011, the system control circuit 214 performs the same image confirmation process as in S005, and advances the process to S012.

  In S012, the system control circuit 214 calculates the degree of balance after the dichroic mirror 300 is rotated downward in the mirror angle. Then, the system control circuit 214 compares the degree of balance after the rotation with the degree of balance just before the rotation, and determines whether or not the degree of balance has decreased due to this rotation. At this time, if the system control circuit 214 determines that the degree of balance has decreased, the system control circuit 214 returns the process to S010, and repeatedly performs the processes of S010 to S012. If the system control circuit 214 determines that the balance has increased due to this rotation, or if it has determined that the balance has not changed, the process proceeds to S013.

  The system control circuit 214 counts the number of times the dichroic mirror 300 has been rotated in S007 and S010, and this time is determined based on the number of times the dichroic mirror 300 has been rotated when the process proceeds from S012 to S013. The rotation angle of the dichroic mirror 300 at is calculated. For example, when the upper direction of the mirror angle is positive, the difference between the number of rotations of the dichroic mirror 300 in S007 and the number of rotations of the dichroic mirror 300 in S010 is taken, and the rotation angle per rotation is taken as the difference. By multiplying by (predetermined angle), the rotation angle of the dichroic mirror 300 from the initial state is calculated.

  In the next step S013, the system control circuit 214 transmits an instruction for rotating the mirror holding frame 321 to the right of the mirror angle by a predetermined angle (for example, angle 1 second) to the mirror driver circuit 212. Then, the mirror driver circuit 212 controls the mirror holding frame rotation motor 325 to rotate the mirror holding frame 321 by a predetermined angle to the right of the mirror angle.

  In next step S014, the system control circuit 214 performs the same image confirmation processing as in step S005, and advances the processing to step S015.

  In S015, the system control circuit 214 calculates the degree of balance after rotating the mirror holding frame 321 in the right direction of the mirror angle. Then, the system control circuit 214 compares the balance degree after the rotation with the balance degree just before the rotation, and determines whether or not the balance is reduced by the rotation. At this time, if the system control circuit 214 determines that the degree of balance has decreased, the system control circuit 214 returns the process to S013 and repeats the processes of S013 to S015. If the system control circuit 214 determines that the balance has increased due to this rotation, or if it has determined that the balance has not changed, the process proceeds to S016.

  In S016, the system control circuit 214 transmits an instruction to rotate the mirror holding frame 321 to the left of the mirror angle by a predetermined angle (for example, angle 1 second) to the mirror driver circuit 212. Then, the mirror driver circuit 212 controls the mirror holding frame rotation motor 325 to rotate the mirror holding frame 321 by a predetermined angle to the left of the mirror angle.

  In the next S017, the system control circuit 214 performs the same image confirmation process as in S005, and advances the process to S018.

  In S018, the system control circuit 214 calculates the degree of balance after rotating the mirror holding frame 321 in the left direction of the mirror angle. Then, the system control circuit 214 compares the degree of balance after the rotation with the degree of balance just before the rotation, and determines whether or not the degree of balance has decreased due to this rotation. At this time, if the system control circuit 214 determines that the degree of balance has decreased, the system control circuit 214 returns the process to S016, and repeatedly performs the processes of S016 to S018. If the system control circuit 214 determines that the balance has increased due to this rotation, or if it has determined that the balance has not changed, the system control circuit 214 advances the process to S019.

  The system control circuit 214 counts the number of times the mirror holding frame 321 has been rotated in steps S013 and S016, and calculates the rotation angle of the mirror holding frame 321 at this point when the process proceeds from S018 to S019. . For example, when the right direction of the mirror angle is positive, the difference between the number of rotations of the mirror holding frame 321 according to S013 and the number of rotations of the mirror holding frame 321 according to S016 is taken, and this difference is calculated for each time. If the rotation angle (predetermined angle) is multiplied, the rotation angle of the mirror holding frame 321 from the initial state is calculated.

  In next S019, the system control circuit 214 stops the emission of the excitation light from the excitation light source 204. In next S020, the system control circuit 214 reads the rotation angle of the dichroic mirror 300 calculated in S012 and the rotation angle of the mirror holding frame 321 calculated in S018 of the fluorescence observation endoscope 10 read in S001. Along with the identification number, it is registered in the storage unit of the system control circuit 214, and a series of processing is completed.

  If the system control circuit 214 determines in S002 that the read identification number is registered in the storage unit of the system control circuit 214, the process proceeds to S021.

  In S021, the system control circuit 214 reads the rotation angle of the dichroic mirror 300 and the rotation angle of the mirror holding frame 321 corresponding to the read identification number from the storage unit of the system control circuit 214.

  In next S022, the system control circuit 214 sends an instruction to rotate the dichroic mirror 300 and the mirror holding frame 321 to the mirror driver circuit 212 based on the rotation angle read in S021. As a result, the dichroic mirror 300 and the mirror holding frame 321 rotate by the rotation angle registered in the storage unit of the system control circuit 214. After the process of S022 is completed, this series of processes is terminated.

  Hereinafter, the internal operations of the light source processor device 20 when the switch for designating the normal observation mode and the switch for designating the fluorescence observation mode are operated will be described.

  When the system control circuit 214 receives an operation signal generated by operating a switch that designates the normal observation mode, the system control circuit 214 controls the power supply circuit 211 to start the white light source 201 to emit white light, The rotation shielding plate 206 is rotated to a position where white light passes and the excitation light source 204 is controlled to stop the emission of excitation light. As a result, only white light is emitted from the distal end of the insertion portion 10a of the fluorescence observation endoscope 10. Then, the video signal processing circuit 213 displays on the monitor 60 a normal observation image that is an image of the subject (that is, a subject illuminated with white light) formed by white light reflected by the surface of the subject. .

  On the other hand, when the system control circuit 214 receives an operation signal generated by operating a switch that designates the fluorescence observation mode, the system control circuit 214 continuously rotates the rotation shielding plate 206. At the same time, the excitation light source 204 is controlled in synchronization with the rotation of the rotation shielding plate 206, and the excitation light source 204 is made to emit the excitation light only when the rotation shielding plate 206 is in a position to shield white light. . Accordingly, excitation light and white light are alternately emitted from the distal end of the insertion portion 10a of the fluorescence observation endoscope 10. Then, the video signal processing circuit 213 captures an image signal obtained by imaging white light reflected from the surface of the subject (image signal of a normal image) and fluorescence emitted from the subject (fluorescence). The fluorescence observation image, which is an image obtained by extracting a portion that is displayed brightly in the normal image but darkly displayed in the fluorescence image as a portion suspected of having a lesion, is displayed on the monitor 60. Display.

  Since it is configured as described above, the endoscope system according to the present invention operates as described below.

  The surgeon turns on the main power of the monitor 60 and the light source processor device 20, turns on the key switch 22, and connects the fluorescence observation endoscope 10 to the light source processor device 20. Then, when the fluorescence observation endoscope 10 has been connected to the light source processor device 20 in the past, the dichroic mirror 300 and the mirror holding are based on the information recorded in the storage unit of the system control circuit 214. The rotation angle of the frame 321 is adjusted (the position of the excitation light incident on the base end face of the light guide 16 is adjusted). Therefore, in this case, before operating the switch panel 23, the intensity distribution of the excitation light emitted from the tip of the light guide 16 is optimized (in the range in which the dichroic mirror 300 and the mirror holding frame 321 rotate) The balance is the lowest).

  In addition, when the fluorescence observation endoscope 10 has not been connected to the light source processor device 20 in the past, a screen indicating that adjustment has not been performed is displayed on the monitor 60. After the distal end of the insertion portion 10a of the fluorescence observation endoscope 10 is fixed to the jig, the intensity distribution of the excitation light emitted from the distal end of the light guide 16 is optimized by operating a switch that designates the start of the adjustment operation. Can be made. In this case, since the light source processor device 20 cannot proceed until the switch for instructing the start of the adjustment operation is pressed (see S003 in FIG. 4), the intensity distribution of the excitation light emitted from the tip of the light guide 16 Can be prevented from being observed in the fluorescence observation mode without being optimized.

  Therefore, according to the endoscope system according to the present invention, when observation in the fluorescence observation mode is performed, the intensity distribution of the excitation light emitted from the tip of the light guide 16 is optimized, so that the excitation light is irradiated. If the state of the biological tissue of the body cavity wall in the range is the same (for example, all normal parts), the intensity of the fluorescence emitted from the range irradiated with the excitation light is within the range imaged by the image sensor 13. It is constant regardless of location. Therefore, the surgeon can accurately determine the presence or absence of a lesion based on the image displayed on the monitor 60.

  In addition, when the switch for instructing the start of the adjustment operation of the switch panel 23 is operated again after the adjustment of the rotation angles of the dichroic mirror 300 and the mirror holding frame 321 is completed, the system control circuit 214 again performs S003 to S020. Processing may be performed. In this case, even when the already registered fluorescence observation endoscope 10 is connected to the light source processor device 20, the rotation angle of the dichroic mirror 300 and the mirror holding frame 321 can be adjusted again. .

  As described above, according to the present invention, the light guide 16 is emitted from the distal end of the light guide 16 even when the base end surface of the light guide 16 is configured to converge light to a diameter smaller than the diameter of the light guide 16. It is possible to provide an endoscope system in which an extreme bias does not occur in the intensity distribution of the excitation light to be generated.

1 is an external view showing an external appearance of an endoscope system according to an embodiment of the present invention. Schematic which shows the internal structure of the light source processor apparatus in an endoscope system Perspective view of dichroic mirror 300 and dichroic mirror rotating device 30 The flowchart which shows operation | movement inside the optical processor apparatus 20 after connecting the fluorescence observation endoscope 10 to the light source device processor apparatus 20. Explanatory drawing showing an example of image division Explanatory drawing which shows the base end surface of the light guide 16

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fluorescence observation endoscope 16 Light guide 20 Light source processor apparatus 30 Dichroic mirror rotation apparatus 60 Monitor 201 White light source 204 Excitation light source 209 Condensing lens 212 Mirror driver circuit 213 Image signal processing circuit 214 System control circuit 300 Dichroic mirror 317 Mirror Rotation motor 321 Mirror holding frame 325 Mirror holding frame rotation motor

Claims (4)

An endoscope system comprising an endoscope and a light source device,
The endoscope is
A light guide that emits a light beam incident on the proximal end side from the distal end side;
An objective optical system for forming an image of an observation object;
An image sensor that captures an image formed by the objective optical system and outputs an image signal;
The light source device is
A white light source that emits white light as parallel light;
An excitation light source unit that emits excitation light for exciting biological tissue as parallel light;
A condensing optical system for converging light traveling through the optical path of white light emitted from the white light source unit toward the proximal end side of the light guide;
The optical path of the white light emitted from the white light source unit and the optical path of the excitation light emitted from the excitation light source unit are arranged at the overlapping position, and transmits the white light and reflects the excitation light. , An optical path synthesis element for advancing the white light and the excitation light toward the condensing optical system;
An optical path synthesis element rotating means for changing the direction of the optical path synthesis element;
An endoscope comprising: a control unit that controls the optical path synthesizing element rotating unit so that an intensity distribution of excitation light emitted from a tip of the light guide is constant in an imaging range of the imaging element. system. 2. The endoscope system according to claim 1, wherein the optical path synthesizing element rotating means rotates the optical path synthesizing element around two rotation axes that intersect each other. The endoscope further includes a storage device that stores an identification number for identifying the endoscope,
For each identification number, the control unit is configured so that each rotation axis of the optical path synthesis element has a constant intensity distribution of excitation light emitted from the tip of the light guide corresponding to the identification number in the imaging range of the imaging element. Each of which stores a rotation angle of the optical path combining element, and when the endoscope and the light source device are connected, the rotation angle of the optical path synthesis element corresponding to the identification number of the endoscope is 3. The endoscope system according to claim 2, wherein the endoscope system is read from a storage unit, and the optical path synthesizing element rotating unit is controlled so that the rotation angle of the optical path synthesizing element becomes the read rotation angle. The control unit divides an image captured by the image sensor into a plurality of regions while the excitation light emitted from the light guide is irradiating the fluorescent plate that emits fluorescence when the excitation light is irradiated. 2. The endoscope system according to claim 1, wherein brightness of each region is compared, and the optical path synthesizing element rotating unit is controlled so that the brightness of each region becomes constant.