JP2017225736A - Endoscope apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope apparatus which uses an imaging unit with two imaging elements laminatingly mounted thereon to enable simultaneous observation of reflection from a subject caused by white light and fluorescence from the subject caused by excitation light with a desired performance attained.SOLUTION: Used is an imaging unit 21 on which are mounted laminatingly, from the side receiving light from a subject, a first light permissive film 60 shielding excitation light, a first imaging element 83 photoelectrically converting white light, and a second imaging element 87 photoelectrically converting fluorescence which has transmitted through the first light permissive film 60 and the first imaging element 83, such that the reflection from the subject and the fluorescence from the subject caused by the excitation light are observed simultaneously. A timing control unit 69 causes an excitation light source K2 to illuminate at least during an illuminating period of a white light source K1 to allow that an image signal from the second imaging element 87 is read simultaneously with the reading of an imaging signal from the first imaging element 83 during at least a part of a period during which the image signal from the first imaging element 83 is read.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an endoscope apparatus.

  2. Description of the Related Art Endoscopic devices that observe tissue in a body cavity are widely known. In general, an endoscope apparatus irradiates an observation part in a body cavity with white light, and an imaging element receives reflected light from the observation part to generate an observation image.

  The electronic endoscope apparatus described in Patent Document 1 irradiates the observation site with excitation light by a blue filter in addition to the normal observation mode in which the observation site is irradiated with visible light, that is, white light, and a full-color normal observation image is displayed. A special observation mode for displaying an autofluorescence observation image and a narrow-band image (NBI image). According to the special observation mode, it is possible to observe things that do not appear in the normal observation image such as blood vessel running.

JP 2007-50106 A Japanese Patent Laying-Open No. 2015-192015

  In the electronic endoscope apparatus described in Patent Document 1, two CCDs (solid-state imaging devices) are provided for observation in the normal observation mode and the special observation mode, and the two CCDs are arranged in parallel. Yes. However, when a plurality of CCDs are arranged in parallel, there is a problem that the diameter of the distal end portion of the endoscope inserted into the body cavity is increased. The solid-state imaging device described in Patent Document 2 has a configuration in which semiconductor substrates on which photoelectric conversion units are formed are stacked in a plurality of stages. Therefore, the above-described problem of the electronic endoscope device of Patent Document 1 can be solved. There is sex. However, when using the solid-state imaging device of Patent Document 2 for the imaging unit of the endoscope, it is necessary to devise for satisfying a desired level of performance such as sensitivity or resolution.

  The present invention has been made in view of the above-described circumstances, and simultaneously reflects light reflected from a subject by white light and fluorescence from the subject by excitation light using an imaging unit in which two imaging elements are stacked. An object of the present invention is to provide an endoscope apparatus that can perform observation while satisfying desired performance.

An endoscope apparatus according to an aspect of the present invention includes:
An illumination unit that emits illumination light from the distal end portion of the endoscope, an imaging unit that images an observation region of the subject irradiated with the illumination light, a control unit that controls the illumination unit and the imaging unit, An endoscopic device comprising:
The illumination unit includes a white light source for generating white light, and an excitation light source for generating excitation light that emits fluorescence from the subject.
The imaging unit includes a plurality of pixels having photoelectric conversion units arranged in a two-dimensional matrix, a first imaging element that generates a visible light image, and a photoelectric conversion unit that photoelectrically converts light transmitted through the first imaging element. A plurality of pixels having a two-dimensional matrix arranged in a two-dimensional matrix, and a first light-transmitting film that transmits light of a fluorescent wavelength component from the subject. The first light transmission film, the first image sensor, and the second image sensor are stacked in that order from the light incident side,
The control unit causes the excitation light source to emit light at least during the light emission period of the white light source, reads an image signal from the second image sensor, and reads an image signal from the first image sensor. The reading is performed simultaneously with the reading of the image signal from the first image sensor during at least a part of the reading period.

  According to the present invention, imaging in which two imaging elements are arranged in a stacked manner is controlled by controlling the light emission period of the light source for white light and the light source for excitation light and the readout timing of image signals from the two imaging elements of the imaging unit. It is possible to provide an endoscope apparatus that can perform simultaneous observation of reflected light from a subject using white light and fluorescence from the subject using excitation light while satisfying desired performance.

1 is an external view of an endoscope apparatus for explaining an embodiment of the present invention. It is a figure which shows the internal structure of the endoscope apparatus of 1st Embodiment. It is a figure which shows the relationship between the wavelength of the light radiate | emitted from the light source K1 of white light of 1st Embodiment, and the light source K2 for excitation light, and relative intensity | strength. It is sectional drawing which shows the structure of a solid-state imaging device. It is a figure which shows the spectral transmission characteristic of a color filter. (A) is a figure which shows an example of the Bayer arrangement in a color filter, (B) is a figure which shows the other example of the Bayer arrangement in a color filter. It is a figure which shows the pixel integrated by the binning process of the image signal obtained from a 2nd image sensor. It is a figure which shows an example of the light emission timing of each light source at the time of setting of 2 types simultaneous observation mode in 1st Embodiment, and the read-out timing of the image signal from each image pick-up element. It is a figure which shows the other example of the light emission timing of each light source at the time of setting of 2 types simultaneous observation mode in 1st Embodiment, and the read-out timing of the image signal from each image pick-up element. It is a figure which shows an example of the light emission timing of each light source at the time of setting of 3 types simultaneous observation mode in 1st Embodiment, and the read-out timing of the image signal from each image pick-up element. It is a figure which shows the internal structure of the endoscope apparatus of 2nd Embodiment. It is a figure which shows the relationship between the wavelength of the light radiate | emitted from the light source K1 of white light of 2nd Embodiment, and the light source K2 for excitation light, and relative intensity | strength. It is a figure which shows an example of the light emission timing of each light source at the time of setting of 3 types simultaneous observation mode in 2nd Embodiment, and the read-out timing of the image signal from each image pick-up element.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is an external view of an endoscope apparatus 100 for explaining an embodiment of the present invention.

  The endoscope apparatus 100 includes an endoscope 11, a control device 13, a display unit 15 such as a liquid crystal display device, and an input unit 17 such as a keyboard and a mouse for inputting information to the control device 13.

  The control device 13 includes an illumination unit 45 and a control unit 47 that performs signal processing of an image signal output from the endoscope 11. A display unit 15 and an input unit 17 are connected to the control unit 47.

  The endoscope 11 includes an endoscope insertion portion 19 that is inserted into a subject, an operation portion 23 that performs an operation for bending and observing the distal end of the endoscope insertion portion 19, and the endoscope 11. Connector portions 25 and 27 are detachably connected to the control device 13.

  The endoscope insertion portion 19 includes a flexible soft portion 29, a bending portion 31, and a distal end portion (hereinafter also referred to as an endoscope distal end portion) 33.

  Although not shown, various channels such as a forceps channel for inserting a tissue collection treatment instrument and the like, a channel for air supply / water supply, and the like are provided inside the operation unit 23 and the endoscope insertion unit 19. .

  FIG. 2 is a diagram showing an internal configuration of the endoscope apparatus 100 shown in FIG.

  The endoscope distal end portion 33 includes an illumination window 35 for irradiating light to an observation region, a diffusion plate 58 disposed opposite to the illumination window 35, and an illumination disposed between the diffusion plate 58 and the illumination window 35. Lens 59, imaging unit 21 that receives light from the observation region, observation window 40 for allowing light from the observation region to enter the light receiving surface of imaging unit 21, observation window 40, and imaging unit 21 Objective lens 39 provided between the two.

  The bending portion 31 is provided between the flexible portion 29 and the endoscope distal end portion 33, and can be bent by a turning operation of an angle knob 43 (see FIG. 1) disposed in the operation portion 23.

  The bending portion 31 can be bent in an arbitrary direction and an arbitrary angle according to a part of the subject in which the endoscope 11 is used, and the illumination window 35 and the observation window of the endoscope distal end portion 33. 40 can be directed to the desired viewing site.

  The control device 13 includes an illumination unit 45 that emits illumination light supplied to the observation region from the illumination window 35 of the endoscope distal end 33, and a control unit 47 that controls the illumination unit 45 and the imaging unit 21. The illumination unit 45 and the control unit 47 are connected to the endoscope 11 via connector units 25 and 27, respectively.

  Hereinafter, the illumination unit 45 of the control device 13 will be described in detail. As shown in FIG. 2, the illumination unit 45 includes a light source driving unit 49, a white light source K <b> 1, an excitation light source K <b> 2, an optical fiber bundle 51, and an optical fiber 53.

  The white light source K1 is a semiconductor element that emits light for normal observation (white light observation) and narrowband light observation. The white light source K1 includes an R-LED (Red-Light Emitting Diode), a G-LED (Green-Light Emitting Diode), a B-LED (Blue-Light Emitting Diode), and a V-LED (Violet-Light Emitting Diode). ) Four-color LEDs (Light Emitting Diodes).

  As shown in FIG. 3, the R-LED is a light emitting diode that emits red light having a wavelength band of 600 to 650 nm. The G-LED is a light emitting diode that emits green light having a wavelength band of 480 to 600 nm. The B-LED is a light emitting diode that emits blue light having a wavelength band of 420 to 500 nm. The V-LED is a light emitting diode that emits purple light having a wavelength band of 380 to 420 nm. White light is generated by combining the light generated by each LED, and the white light is emitted from the white light source K1. The white light source K1 may be a xenon lamp or a white LED.

  The excitation light source K2 is a light source for fluorescence observation. The excitation light source K2 is a laser diode that emits laser light having a central wavelength of 780 nm (excitation light in the near infrared band) for exciting ICG (indocyanine green) injected into the subject. Note that the wavelength of fluorescence emitted by the excitation of ICG is 800 to 900 nm.

  In addition, as a light source combining the white light source K1 and the excitation light source K2, each of the R component, G component, and B component filter elements and the near infrared component filter element having a transmission wavelength of 780 nm are rotated. It is also possible to use a surface sequential exposure type illuminating unit combining a rotating filter and a xenon lamp arranged in the above.

  The light source K1 for white light and the light source K2 for excitation light are individually driven by the light source drive unit 49 according to the observation mode of the subject. In the observation mode, “normal observation mode” in which white light is irradiated on the observation region of the subject to observe the reflected light, and excitation light is irradiated on the observation region of the subject into which the ICG has been injected to emit fluorescence. `` Fluorescence observation mode '' to observe, `` Narrow band light observation mode '' to observe the reflected light by irradiating the observation area of the subject with light in a specific wavelength region of visible light, normal observation and fluorescence observation There are “two-type simultaneous observation mode” in which simultaneous observation is performed, and “three-type simultaneous observation mode” in which normal observation, fluorescence observation, and narrow-band light observation are simultaneously performed. The light source driver 49 emits light only from the white light source K1 in the normal observation mode and the narrow-band light observation mode, and emits light only from the excitation light source K2 in the fluorescence observation mode. Light is emitted from both the light sources K1 and K2 in the time and three simultaneous observation modes. In addition, when white LED is used as the light source K1 for white light, the light irradiated to the observation region when performing narrow-band light observation is light in a specific wavelength region among visible light emitted from the white LED. Light that has passed through a filter (not shown) that passes through.

  White light emitted from the white light source K1 is input to the optical fiber bundle 51 via a condenser lens (not shown). Excitation light emitted from the excitation light source K2 is input to the optical fiber 53 via a condenser lens (not shown). The optical fiber bundle 51 and the optical fiber 53 are bundled together by a light guide 55. The light guide 55 extends to the endoscope distal end portion 33 via the connector portion 25. The light emitted from the end face of the light guide 55 on the endoscope distal end 33 side is diffused by the diffusion plate 58 and then emitted from the illumination window 35 through the lens 59.

  The light source driving unit 49 drives both the light sources K1 and K2 independently by pulse driving. That is, the light source drive unit 49 supplies different drive signals (drive pulse patterns) to the respective light sources. The light source emits light during the period when the drive pulse is at a high level. The light source drive unit 49 drives the R-LED, G-LED, B-LED, and V-LED independently during the drive control of the white light source K1.

  Next, the imaging unit 21 provided at the endoscope distal end portion 33 will be described in detail. As shown in FIG. 2, the imaging unit 21 includes a first light transmission film 60 and a solid-state imaging device 61, and images an observation region of a subject irradiated with light from the illumination unit 45. Light from the subject passes through the objective lens 39 and the first light transmission film 60 and enters the solid-state imaging device 61. The first light transmission film 60 is an excitation light cut filter having a characteristic of blocking light having a wavelength component of excitation light emitted from the excitation light source K2, that is, light having a wavelength of 780 nm. The first light transmission film 60 is laminated on the light receiving surface side of the solid-state imaging device 61.

  As shown in FIG. 4, the solid-state imaging device 61 includes a color filter 93, a first imaging element 83, a second light transmission film 89, and a second imaging element 87, and the incident side of light from the subject To have a configuration in which they are stacked in this order.

  The color filter 93 separates RGB components of the light incident on the solid-state imaging device 61 and transmits infrared light having a wavelength of about 790 nm or more. The arrangement pattern of the color filter 93 is a Bayer arrangement in which the RGB color components are arranged in a zigzag pattern, but even if the general Bayer arrangement shown in FIG. A Bayer array with many B components shown in FIG. The color filter 93 is arranged so that each color component corresponds to a pixel described later of the first image sensor 83.

  FIG. 5 is a diagram showing the spectral transmission characteristics of the color filter 93. The R component of the color filter 93 transmits red light R having a wavelength band of 550 to 700 nm and infrared light having a wavelength of about 790 nm or more, as indicated by a dotted line in FIG. The G component transmits green light G having a wavelength band of 460 to 630 nm and infrared light having a wavelength of about 790 nm or more, as indicated by a one-dot chain line in FIG. Further, as shown by a two-dot chain line in FIG. 5, the B component transmits blue light B having a wavelength band of 380 to 550 nm and infrared light having a wavelength of about 790 nm or more. As described above, the color filter 93 sufficiently transmits infrared light including light of 800 to 900 nm which is a fluorescent component in any color component. However, among the three components, only the G component or B component having a high composition ratio in the Bayer array may transmit infrared light having a wavelength of about 790 nm or more.

  The first image sensor 83 is configured by arranging a plurality of pixels each having the photoelectric conversion unit 81 in a two-dimensional matrix, and generates a visible light image.

  The second light transmission film 89 is a white light cut filter having a characteristic of blocking the wavelength component of white light, that is, light having a wavelength band of about 750 nm or less. By providing the second light transmission film 89 between the first image sensor 83 and the second image sensor 87, a noise component of light for the second image sensor 87 can be removed.

  The second imaging element 87 includes a pixel having a photoelectric conversion unit 85 that photoelectrically converts light having a wavelength component (800 to 900 nm) of fluorescence from the subject that has passed through the first imaging element 83 and the second light transmission film 89. A plurality of elements are arranged in a two-dimensional matrix. The position of the pixel of the first image sensor 83 and the position of the pixel of the second image sensor 87 viewed from the light incident side overlap each other. Accordingly, the color components of the color filter 93, the pixels of the first image sensor 83, and the pixels of the second image sensor 87 overlap each other when viewed from the light incident side.

  The light receiving area of the photoelectric conversion unit 85 in each pixel of the second image sensor 87 is larger than the light receiving area of the photoelectric conversion unit 81 in each pixel of the first image sensor 83. If the light receiving area of the photoelectric conversion unit 85 is large, the second imaging element 87 can achieve a desired sensitivity even if the fluorescence from the subject is weak.

  Both the first image sensor 83 and the second image sensor 87 are CMOS (Complementary Metal Oxide Semiconductor) image sensors, and are driven by a rolling shutter system. For this reason, the first image sensor 83 and the second image sensor 87 have a plurality of columns of pixel rows (n rows of Line 1 to Line n) as drive units, and are exposed for each pixel row under the control of the control unit 47. It is driven by shifting the time and the readout period of the image signal (charge). That is, reading of the image signal from the image sensor is sequentially performed while shifting for each pixel row, and exposure of the image sensor is performed for each pixel row by the electronic shutter, and exposure is performed except when the image signal is read.

  Next, the control unit 47 of the control device 13 will be described in detail. As shown in FIG. 2, the control unit 47 includes a storage unit 71, a timing control unit 69, and a signal processing unit 66.

  The storage unit 71 includes a duty ratio of each drive pulse constituting a drive signal supplied to each LED of the white light source K1 included in the illumination unit 45, a timing at which the on / off level of each drive pulse is switched, and the imaging unit 21. A first table in which the timing for reading an image signal (charge) from the first image sensor 83 of the solid-state imaging device 61 is defined is stored. In addition, the storage unit 71 includes a duty ratio of a driving pulse that constitutes a driving signal supplied to the excitation light source K2, a timing at which the on / off level of the driving pulse is switched, and a first of the solid-state imaging device 61 included in the imaging unit 21. 2 The second table in which the timing for reading the image signal (charge) from the image sensor 87 is stored.

  The timing control unit 69 determines a light source to be driven according to an observation mode set according to an instruction from the operation unit 23 or the input unit 17 of the endoscope 11. In addition, the timing control unit 69 uses the light sources K1 and K2 performed by the light source driving unit 49 based on at least one of the information defined in the first table and the information defined in the second table stored in the storage unit 71. The timing of driving and the timing of image signal readout by the signal processing unit 66 from the first image sensor 83 and the second image sensor 87 are controlled.

  The signal processing unit 66 performs signal processing on the image signal from the endoscope 11 read according to the control from the timing control unit 69 to generate image data. An image based on the image data generated by the signal processing unit 66 is displayed on the display unit 15. Note that the normal observation image, the fluorescence observation image, and the narrowband light observation image generated by the signal processing unit 66 may be displayed side by side or may be displayed in a superimposed manner.

  Note that the signal processing unit 66 performs binning processing on the image signal from the second image sensor 87 and reads it out. That is, as illustrated in FIG. 7, the signal processing unit 66 regards a plurality of adjacent (for example, 2 × 2 = 4) pixels of the second image sensor 87 as one pixel, and images of the plurality of adjacent pixels. The signal is integrated into one image signal. This apparently improves the light receiving sensitivity of the second image sensor 87 that receives infrared light having a wavelength of about 790 nm or more. Further, by causing the pixels of the second image sensor 87 read out by binning processing to correspond to the repeating unit of the Bayer array of the color filter 93, the influence due to the difference in the transmittance of infrared light due to the RGB components of the color filter 93 is eliminated. it can. Note that the number of pixels integrated by the binning process may be a multiple of 2 × 2. Instead of performing the binning process, the size of the pixel of the second image sensor 87 may be set to a size corresponding to the repeating unit of the Bayer array of the color filter 93.

  Hereinafter, operation | movement of the endoscope apparatus 100 of 1st Embodiment is demonstrated in detail with reference to FIGS. 8-10. When the operator presses an observation mode switching button 73 (see FIG. 2) provided on the endoscope 11, the timing control unit 69 performs a normal observation mode, a fluorescence observation mode, a narrowband light observation mode, and a normal observation. The mode is switched to the two types of simultaneous observation mode in which the fluorescence observation is performed simultaneously, and the three types of simultaneous observation mode in which the normal observation, the fluorescence observation, and the narrowband light observation are performed simultaneously.

  FIG. 8 shows an example of the operation of the endoscope apparatus 100 when the two-type simultaneous observation mode is set. In the example shown in FIG. 8, the timing control unit 69 causes all the LEDs of the white light source K1 to emit light at a predetermined duty ratio, and causes the excitation light source K2 to emit light only during the light emission period of the white light source K1. The light source drive unit 49 is controlled. In addition, the timing control unit 69 reads out each image signal from the first imaging element 83 and the second imaging element 87 included in the solid-state imaging device 61 of the imaging unit 21 by using the white light source K1 and the excitation light source K2. The signal processing unit 66 is controlled to be performed during the non-light emitting period. That is, the reading of the image signal from the second image sensor 87 is performed simultaneously with the reading of the image signal from the first image sensor 83 in all the reading periods of the image signal reading period from the first image sensor 83. Note that the readout of each image signal from the first image sensor 83 and the second image sensor 87 is shifted for each pixel row in each element because the first image sensor 83 and the second image sensor 87 are both CMOS. It is done sequentially.

  According to this operation example, an image signal of reflected light from the observation region irradiated with white light (VGRB) and a wavelength emitted from the observation region by irradiation with excitation light (IR) having a central wavelength of 780 nm. Since fluorescence image signals with a bandwidth of 800 to 900 nm are read simultaneously, normal observation and fluorescence observation can be performed simultaneously at the same frame rate. In addition, since the image signal for normal observation and the image signal for fluorescence observation are obtained from one solid-state imaging device 61, without increasing the diameter of the endoscope insertion portion 19 inserted into the body cavity, The endoscope apparatus 100 capable of the two-type simultaneous observation mode at the same frame rate can be realized.

  If the second imaging element 87 cannot obtain sufficient sensitivity because the fluorescence emitted from the observation region is weak, the signal processing unit 66 performs the binning process described above, thereby performing the fluorescence observation. Although the resolution is lowered, fluorescence observation with a desired sensitivity is possible.

  FIG. 9 shows another example of the operation of the endoscope apparatus 100 when the two-type simultaneous observation mode is set. In the example shown in FIG. 9, the timing control unit 69 controls the light source driving unit 49 so that all LEDs of the white light source K1 emit light with a predetermined duty ratio, and the solid-state imaging device 61 of the imaging unit 21 has the first. The signal processing unit 66 is controlled to read out the image signal from the one image sensor 83 during the non-light emission period of the white light source K1. In addition, the timing control unit 69 reads out the image signal from the second image sensor 87 during every other readout period of the image signal readout period from the first image sensor 83. Simultaneously with signal readout. Further, the timing control unit 69 uses the excitation light source K2 as the light emission period of the white light source K1 and the readout period of the image signal from the first image sensor 83, and the image signal from the second image sensor. The light source driver 49 is controlled to emit light during the period T1 during which no reading is performed.

  According to this operation example, readout of a fluorescent image signal having a wavelength band of 800 to 900 nm emitted from the observation region by irradiating excitation light (IR) having a central wavelength of 780 nm is irradiated with white light (VGRB). However, since the exposure period of the second image sensor 87 is three times that of the first image sensor 83, it is emitted from the area to be observed. Even if the fluorescence is weak, fluorescence observation with desired sensitivity and normal observation can be performed simultaneously. In addition, since the image signal for normal observation and the image signal for fluorescence observation are obtained from one solid-state imaging device 61, without increasing the diameter of the endoscope insertion portion 19 inserted into the body cavity, The endoscope apparatus 100 capable of the two-type simultaneous observation mode with a desired sensitivity can be realized.

  FIG. 10 shows an example of the operation of the endoscope apparatus 100 when the three-type simultaneous observation mode is set. In the example shown in FIG. 10, the light emission period of the excitation light source K2 and the readout timing of the image signal from the second image sensor 87 are the same as in the example shown in FIG. 9, but the timing control unit 69 has a predetermined duty. In the light emission period of the white light source K1 driven by the ratio, light emission of all LEDs for normal observation and light emission of only the G-LED and B-LED for narrowband light observation are alternately performed. The light source drive unit 49 is controlled. Note that the reading of the image signal from the first image sensor 83 is performed during a non-light emission period in which all the LEDs of the white light source K1 are turned off.

  According to this operation example, the readout of the image signal of the reflected light from the observation region irradiated with white light (VGRB) and the observation of the visible light irradiated with light (GB) only in a specific wavelength band Reading of the image signal of the reflected light from the area is performed at a half frame rate as compared with the example shown in FIG. 8 or the example shown in FIG. 9, but normal observation, fluorescence observation, and narrowband light observation are performed simultaneously. Can do. In addition, since an image signal for normal observation, an image signal for fluorescence observation, and an image signal for narrowband light observation are obtained from one solid-state imaging device 61, an endoscope insertion portion inserted into a body cavity The endoscope apparatus 100 capable of the three-type simultaneous observation mode can be realized without causing the 19 diameter to increase.

  As described above, according to the present embodiment, each of the white light source K1 and the excitation light source K2 included in the illuminating unit 45 and one solid that can reduce the diameter of the endoscope insertion unit 19 can be realized. The readout operations of the first imaging element 83 and the second imaging element 87 included in the imaging device 61 are controlled so as to cooperate at the same timing. For this reason, normal observation by reflected light from the subject with white light and fluorescence observation from the subject with excitation light can be performed simultaneously at the same frame rate or desired sensitivity. In addition, when the second imaging element 87 cannot obtain sufficient sensitivity because the fluorescence is weak, fluorescence observation with a desired sensitivity can be performed by performing a binning process.

(Second Embodiment)
A second embodiment will be described with reference to FIGS. Note that the second embodiment differs from the first embodiment in the wavelength of the excitation light emitted from the excitation light source K2 and the fluorescent material injected into the subject. Except for this point, the second embodiment is the same as the first embodiment, and therefore, the description of the same or equivalent matters as the first embodiment is simplified or omitted.

  FIG. 11 is a diagram illustrating an internal configuration of the endoscope apparatus according to the second embodiment. As shown in FIG. 11, the excitation light source K2 of the second embodiment is a light source for fluorescence observation, as in the first embodiment, but for exciting the fluorescent material injected into the subject. It is a laser diode that generates laser light (excitation light) having a center wavelength of 670 nm. In addition, the wavelength of the fluorescence which the said fluorescent substance emits when excited is 700-900 nm. In addition, as shown in FIG. 12, 670 nm light belongs to the wavelength band of R component among visible light. For this reason, in this embodiment, the 1st light transmissive film | membrane 60 which is an excitation light cut filter is not provided.

  Hereinafter, the operation of the endoscope apparatus 200 of the second embodiment will be described in detail with reference to FIG.

  FIG. 13 shows an example of the operation of the endoscope apparatus 200 when the three simultaneous observation mode is set. In the example illustrated in FIG. 13, the timing control unit 69 controls the light source driving unit 49 so that the excitation light source K2 emits light with a predetermined duty ratio, and the second imaging element 87 included in the solid-state imaging device 61 of the imaging unit 21. The signal processing unit 66 is controlled so that the image signal is read out during the non-light emission period of the excitation light source K2. The timing control unit 69 synchronizes the light emission period of the white light source K1 with the light emission period of the excitation light source K2, but the light emission period of all the LEDs for normal observation in the light emission period of the white light source K1. The light source driving unit 49 is controlled so that light emission and light emission of only the G-LED and B-LED for narrowband light observation are performed alternately. The readout of the image signal from the first image sensor 83 is performed at the same time as the readout of the image signal from the second image sensor 87 and in a non-light emission period in which all the LEDs of the white light source K1 are turned off. Note that the readout of each image signal from the first image sensor 83 and the second image sensor 87 is shifted for each pixel row in each element because the first image sensor 83 and the second image sensor 87 are both CMOS. It is done sequentially.

  According to this operation example, since the excitation light is reflected in the image of the display unit 15 during normal observation, the irradiation position of the excitation light becomes clear. Therefore, normal observation can be performed while confirming the correct irradiation position of the excitation light. On the other hand, excitation light does not appear in the image of the display unit 15 during narrowband light observation due to the characteristics of the G component and B component filter elements of the color filter 93. Accordingly, an appropriate narrow-band light observation image without excitation light reflection can be obtained. Furthermore, normal observation, fluorescence observation, and narrow-band light observation can be performed simultaneously. In addition, since the image signal for normal observation, the image signal for fluorescence observation, and the narrow-band light observation are obtained from one solid-state imaging device 61, the diameter of the endoscope insertion portion 19 inserted into the body cavity is increased. Thus, it is possible to realize the endoscope apparatus 200 capable of the three-type simultaneous observation mode.

  As described above, according to the present embodiment, each of the white light source K1 and the excitation light source K2 included in the illuminating unit 45 and one solid that can reduce the diameter of the endoscope insertion unit 19 can be realized. The readout operations of the first imaging element 83 and the second imaging element 87 included in the imaging device 61 are controlled so as to cooperate at the same timing. Therefore, even when the wavelength of the excitation light is included in the visible light wavelength region, normal observation by reflected light from the subject with white light, fluorescence observation from the subject with excitation light, and narrowband Narrow-band light observation using light reflected from the subject can be performed simultaneously. In addition, when the second imaging element 87 cannot obtain sufficient sensitivity because the fluorescence is weak, fluorescence observation with a desired sensitivity can be performed by performing a binning process.

  In the second embodiment, the R-LED that constitutes the white light source K1 may also be used as a light source that generates light (excitation light) for exciting the fluorescent material injected into the subject. . In this case, the illumination unit 45 is not provided with the excitation light source K2.

  In the first embodiment described above, the case where excitation light having a center wavelength of 780 nm is used has been described. In the second embodiment, the case where excitation light having a center wavelength of 670 nm is used has been described. Light may be used. That is, excitation light corresponding to the wavelength of light excited by the fluorescent material input to the subject is used.

  In the above description, the first light transmission film 60 and the solid-state imaging device 61 are configured as separate bodies. However, the first light transmission film 60 and the solid-state imaging device 61 may be configured integrally. In this case, the color filter 93 may be provided with the function of the first light transmission film 60.

  In the above description, the case where the endoscope insertion portion 19 inserted into the body cavity is a so-called flexible mirror having flexibility has been described. However, the endoscope apparatuses 100 and 200 according to the present invention can be used as endoscopes. It is also possible to apply to a so-called rigid mirror camera head in which the insertion portion is formed of a hard material.

As described above, the endoscope apparatus disclosed in this specification is
An illumination unit that emits illumination light from the distal end portion of the endoscope, an imaging unit that images an observation region of the subject irradiated with the illumination light, a control unit that controls the illumination unit and the imaging unit, An endoscopic device comprising:
The illumination unit includes a white light source for generating white light, and an excitation light source for generating excitation light that emits fluorescence from the subject.
The imaging unit includes a plurality of pixels having photoelectric conversion units arranged in a two-dimensional matrix, a first imaging element that generates a visible light image, and a photoelectric conversion unit that photoelectrically converts light transmitted through the first imaging element. A plurality of pixels having a two-dimensional matrix arranged in a two-dimensional matrix, and a first light-transmitting film that transmits light of a fluorescent wavelength component from the subject. The first light transmission film, the first image sensor, and the second image sensor are stacked in that order from the light incident side,
The control unit causes the excitation light source to emit light at least during the light emission period of the white light source, reads an image signal from the second image sensor, and reads an image signal from the first image sensor. The reading is performed simultaneously with the reading of the image signal from the first image sensor during at least a part of the reading period.

  Further, the control unit causes the excitation light source to emit light only during a light emission period of the white light source, and reads out the image signal from the second image sensor, and reads the image signal from the first image sensor. The reading is performed simultaneously with the reading of the image signal from the first image sensor in all reading periods of the reading period.

  In addition, the control unit reads out the image signal from the second image sensor during every other readout period of the image signal readout period from the first image sensor. This is performed simultaneously with reading.

  In addition, the control unit causes the excitation light source to emit light during a period in which an image signal is read from the first image sensor and no image signal is read from the second image sensor.

  The light receiving area of the photoelectric conversion unit of the second image sensor is larger than the light receiving area of the photoelectric conversion unit of the first image sensor.

  Further, the control unit reads out an image signal from the second image sensor by performing a binning process.

In addition, the imaging unit includes a RGB color filter arranged in a Bayer arrangement that transmits light having a fluorescent wavelength component from the subject between the first light transmission film and the first imaging element.
The pixel of the image signal of the second image sensor read out by the binning process is a pixel corresponding to the repeating unit of the Bayer array.

  In addition, the imaging unit includes a second light transmission film that does not transmit the light having the wavelength component of the white light between the first imaging element and the second imaging element.

  The white light source is composed of a plurality of light emitting diodes having different emission wavelengths, and the excitation light source is composed of a laser diode.

  Further, the white light source is composed of a plurality of light emitting diodes having different emission wavelengths, and the excitation light source is composed of one of the plurality of light emitting diodes constituting the white light source. .

  The first image sensor and the second image sensor are sensors driven by a rolling shutter system.

21 Imaging unit 45 Illumination unit 60 First light transmission film 61 Solid-state imaging device 69 Timing control unit 81 Photoelectric conversion unit 83 First imaging device 85 Photoelectric conversion unit 87 Second imaging device 93 Color filter 100, 200 Endoscope device 89 First 2 light transmission film K1 Light source for white light K2 Light source for excitation light

Claims (11)

An illumination unit that emits illumination light from the distal end portion of the endoscope, an imaging unit that images an observation region of the subject irradiated with the illumination light, a control unit that controls the illumination unit and the imaging unit, An endoscopic device comprising:
The illumination unit has a white light source for generating white light, and an excitation light source for generating excitation light for emitting fluorescence from the subject,
The imaging unit includes a plurality of pixels having photoelectric conversion units arranged in a two-dimensional matrix, a first imaging element that generates a visible light image, and a photoelectric conversion unit that photoelectrically converts light transmitted through the first imaging element. A plurality of pixels having a two-dimensional matrix arranged in a two-dimensional matrix, and a first light transmission film that transmits light of a fluorescent wavelength component from the subject, The first light transmission film, the first image sensor, and the second image sensor are stacked in that order from the light incident side,
The control unit causes the excitation light source to emit light at least during a light emission period of the white light source, reads an image signal from the second image sensor, and reads an image signal from the first image sensor. An endoscope apparatus that performs simultaneously with reading of an image signal from the first image sensor during a reading period of at least a part of the period. The endoscope apparatus according to claim 1,
The control unit causes the excitation light source to emit light only during a light emission period of the white light source, reads an image signal from the second image sensor, and reads an image signal from the first image sensor. An endoscope apparatus that performs simultaneously with the reading of the image signal from the first image sensor during all the reading periods. The endoscope apparatus according to claim 1,
The control unit reads out the image signal from the second image sensor, and reads out the image signal from the first image sensor in every other readout period of the image signal readout period from the first image sensor. An endoscopic device that is performed at the same time. The endoscope apparatus according to claim 3,
An endoscope for causing the excitation light source to emit light during a period in which an image signal is read from the first image sensor and a period in which the image signal is not read from the second image sensor. apparatus. The endoscope apparatus according to any one of claims 1 to 4,
An endoscope apparatus in which a light receiving area of a photoelectric conversion unit of the second image sensor is larger than a light receiving area of a photoelectric conversion unit of the first image sensor. The endoscope apparatus according to any one of claims 1 to 5,
The said control part is an endoscope apparatus which reads the image signal from a said 2nd image sensor by binning processing. The endoscope apparatus according to claim 6, wherein
The imaging unit includes a RGB color filter arranged in a Bayer arrangement that transmits light of a fluorescent wavelength component from the subject between the first light transmission film and the first imaging element.
An endoscope apparatus, wherein a pixel of an image signal of the second image sensor read out by the binning process is a pixel corresponding to a repeating unit of the Bayer array. The endoscope apparatus according to any one of claims 1 to 7,
The endoscope apparatus, wherein the imaging unit includes a second light transmission film that does not transmit light having a wavelength component of the white light between the first imaging element and the second imaging element. The endoscope apparatus according to any one of claims 1 to 8,
The endoscope apparatus, wherein the white light source is configured by a plurality of light emitting diodes having different emission wavelengths, and the excitation light source is configured by a laser diode. The endoscope apparatus according to any one of claims 1, 2, and 5 to 8,
The white light source is constituted by a plurality of light emitting diodes having different emission wavelengths, and the excitation light source is constituted by one of the plurality of light emitting diodes constituting the white light source. Endoscopic device. The endoscope apparatus according to any one of claims 1 to 10,
The endoscope apparatus, wherein the first image sensor and the second image sensor are sensors driven by a rolling shutter system.

Images