JP2009095539A - Electronic endoscope of endoscope apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic endoscope of an endoscope apparatus capable of guiding a laser beam for PDT (Photodynamic Therapy) without occupying a forceps channel. <P>SOLUTION: This electronic endoscope 10 of the endoscope system 1 includes: a first light guide 11 for transmitting a regular white light from a light source 73 of a processor 50; a second light guide (first to third fiber cables 27a-27c) for transmitting the laser beam for PDT to the first light guide 11; and an imaging device 14 for imaging a subject to which at least one of the regular white light and the laser beam for the PDT is applied via the first light guide 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electronic endoscope of an endoscope apparatus, and more particularly to an apparatus capable of PDT using a PDT laser beam.

  2. Description of the Related Art Conventionally, an endoscope apparatus has been proposed that performs treatment of a lesion site (photodynamic therapy: PDT) by irradiating a living body with laser light.

Patent Document 1 discloses an endoscope apparatus capable of PDT.
JP 2006-94907 A

  However, in Patent Document 1, it is necessary to provide a light guide that guides the PDT laser light separately from the light guide that normally guides white light up to the distal end portion of the electronic endoscope. Therefore, the problem that the forceps channel is occupied has occurred.

  Accordingly, an object of the present invention is to provide an electronic endoscope of an endoscope apparatus capable of guiding a PDT laser beam without occupying a forceps channel.

  The electronic endoscope of the endoscope apparatus according to the present invention includes a first light guide that transmits the first irradiation light from the light source device, and a second light that transmits the second irradiation light for PDT to the first light guide. A guide; and an imaging element that captures an image of a subject irradiated with at least one of the first irradiation light and the second irradiation light via the first light guide.

  Preferably, a shutter that can switch between transmission and shading of light from the first irradiation light is further provided for switching light irradiated through the first light guide.

  More preferably, an optical sensor that detects the second irradiation light is further provided, and when the optical sensor detects the second irradiation light, the shutter blocks light from the first irradiation light.

  In addition, preferably, when imaging a subject irradiated with the second irradiation light through the first light guide, a charge accumulation period for obtaining an image signal in the imaging element is set short.

  Preferably, the first irradiation light is white light, and the second irradiation light is PDT laser light.

  The electronic endoscope of the endoscope apparatus according to the present invention includes a first incident surface on which the first irradiation light from the light source device is incident, and a second incident surface on which the second irradiation light from the PDT light source device is incident. A first light guide member having a first light output surface for emitting light incident from the first light input surface and the second light input surface, and light emitted from the first light output surface of the first light guide member at one end. A first light guide that emits light that is incident and is incident on one end from the other end, and an imaging device that captures an image of a subject irradiated with the light emitted from the other end of the first light guide.

  Preferably, a shutter provided on the first incident surface side and capable of blocking the first irradiation light, a second light guide for guiding the second irradiation light to the second incident surface of the first light guide member, and the second irradiation A light sensor for detecting light, and when the light sensor detects the second irradiation light, the first irradiation light is blocked, the second irradiation light is guided to one end of the first light guide, and the light sensor is irradiated with the second irradiation light. When light is not detected, the apparatus further includes a control unit that controls the opening and closing of the shutter so that the first irradiation light passes through the shutter and is guided to one end of the first light guide.

  Preferably, the light source device is disposed between an excitation light source device that emits excitation light for fluorescence observation, the first light guide member, and one end portion of the first light guide, and light from the first light guide member is transmitted. An incident third incident surface; a fourth incident surface on which excitation light is incident; and a second incident surface that emits light incident from the third incident surface and the fourth incident surface to one end of the first light guide. A second light guide member;

  As described above, according to the present invention, it is possible to provide an electronic endoscope of an endoscope apparatus capable of guiding PDT laser light without occupying a forceps channel.

  Hereinafter, an embodiment according to the present invention will be described with reference to FIGS. The endoscope apparatus 1 in the present embodiment is an electronic endoscope apparatus including an electronic endoscope 10, a processor 50, and an image display device 90 such as a monitor.

  The electronic endoscope 10 includes a first light guide 11 such as an optical fiber cable, a light distribution lens 12, an objective lens 13, an image sensor 14, an image sensor amplifier 15, a first timing controller 16, a first video signal processing unit 17, Excitation light LD driver 18, excitation light laser diode (LD) 19, excitation light cut filter 20, first optical unit 21, liquid crystal shutter 23, first rod lens 24, foot switch 25, PDT (Photodynamic Therapy) laser diode 26, first, second and third optical fiber cables (second light guides) 27a, 27b and 27c, optical connector 28, optical filter 29, optical sensor 30, second optical unit 31, First system control unit 33, image sensor driver 34, operation unit 44 The first half mirror HM1, the second rod lens 80, the second half mirror HM2, and the beam splitter BS, and normal white light from the light source 73 on the light source device side such as the processor 50 or excitation of the electronic endoscope 10 The excitation light from the laser diode 19 for light is irradiated through the light distribution lens 12 into the body, which is the subject, and is imaged by the image sensor 14 through the objective lens 13. Further, the subject is irradiated with the PDT laser light from the PDT laser diode 26 via the light distribution lens 12.

  The members for guiding the light from the light source 73 to the tip portion of the electronic endoscope 10 are, from the light source 73 side, the first rod lens 24, the liquid crystal shutter 23, the first half mirror HM1, and the second rod lens 80. The beam splitter BS, the first light guide 11, and the light distribution lens 12 are arranged in this order.

  The members for guiding the PDT laser light from the PDT laser diode 26 to the first half mirror HM1 are the first optical fiber cable 27a, the optical connector 28, and the second optical fiber cable from the PDT laser diode 26 side. 27b, the second half mirror HM2, the third optical fiber cable 27c, and the second optical unit 31 are arranged in this order.

  The first video signal processing unit 17 includes a memory controller 17a, a first memory 17b, a second memory 17c, a brightness detection unit 17d, a scan converter 17e, and a comparator 17f.

  The processor 50 includes a condenser lens 51, a second video signal processing unit 58, an image processing unit 59, a subsequent video signal processing unit 60, a second system control unit 71, a second timing controller 72, a light source 73, an aperture control driver 76a, A diaphragm motor 76b and a diaphragm 76c are provided, and irradiation light (usually white light) and electric power are supplied to the electronic endoscope 10 to perform image processing on an image signal of a subject imaged by the electronic endoscope 10. Then, it is converted into a video signal that can be observed on the image display device 90 side.

  First, each part of the electronic endoscope 10 will be described. The first light guide 11 transmits normal white light from the light source 73, excitation light from the excitation light laser diode 19, or PDT laser light from the PDT laser diode 26 to the distal end portion of the electronic endoscope 10. To do. The light transmitted by the first light guide 11 is applied to the subject via the light distribution lens 12.

  The imaging element 14 captures, as an optical image, reflected light (subject image or fluorescence when irradiated with excitation light from the excitation light laser diode 19) from an object incident through the objective lens 13 and the excitation light cut filter 20. To do. When the PDT laser light from the PDT laser diode 26 is irradiated, the charge accumulation period for obtaining the image signal in the image sensor 14 is adjusted to be short in order to prevent halation (hereinafter, the PDT laser light is The image when irradiated is called a PDT image). In the case of imaging using normal white light from the light source 73 and imaging using excitation light from the excitation light laser diode 19, the charge accumulation period for obtaining the image signal in the image sensor 14 is not particularly adjusted.

  In the charge accumulation period adjustment for obtaining the image signal in the image sensor 14, the first video signal processing unit 17 compares the luminance information regarding the image signal of the PDT image with the luminance threshold for the PDT image, and the comparison result is the charge accumulation. This is performed by being transmitted to the first timing controller 16 as a period adjustment signal.

  Specifically, the memory controller 17a controlled by the first timing controller 72 temporarily stores, in the first memory 17b, image signals related to the normal white image and the PDT image among the image signals from the image pickup device amplifier 15, and the fluorescence image. Are temporarily recorded in the second memory 17c, and then output to the second video signal processing unit 58 via the scan converter 17e that performs conversion processing in accordance with the horizontal synchronization frequency of the processor 50 and the image display device 90.

  The brightness detection unit 17d detects luminance information from the image signal related to the PDT image temporarily recorded in the first memory 17b. The comparator 17f compares the luminance information of the image signal relating to the PDT image with a preset luminance threshold value for the PDT image, and as a comparison result, charge accumulation relating to the charge accumulation period for acquiring the image signal by the electronic shutter in the image sensor 14. The period adjustment signal is output to the image sensor driver 34 via the first timing controller 16. A phase shifter (not shown) included in the image sensor driver 34 outputs, to the image sensor 14, a charge accumulation period adjustment pulse whose timing (phase) for outputting an ON signal is adjusted based on the charge accumulation period adjustment signal. (See FIG. 4). The image sensor 14 discharges the accumulated charge during the period until the on signal of the charge accumulation period adjustment pulse is output, and the accumulated charge from the output of the on signal to the end of one field. And output as an image signal of a PDT image.

  When the brightness of the image signal related to the PDT image corresponding to the charge accumulation period adjustment signal is high and it is necessary to darken the PDT image, an on signal of the charge accumulation period adjustment pulse is output at a later timing to set the charge accumulation period. shorten. When the brightness of the image signal related to the PDT image corresponding to the charge accumulation period adjustment signal is low and it is necessary to brighten the PDT image, an on signal of the charge accumulation period adjustment pulse is output at an early timing to set the charge accumulation period. Lengthen.

  FIG. 4 has a relatively long charge accumulation period (1) in the two first half field periods, and has a relatively short charge accumulation period (2) in the latter three one field periods. The waveform of the charge accumulation period adjustment pulse is shown.

  The excitation light cut filter 20 removes light in a short wavelength band including the wavelength band of light emitted from the excitation light laser diode 19 (see FIG. 3). The image sensor amplifier 15 amplifies an image signal related to an optical image obtained by imaging. The amplification factor in the image sensor amplifier 15 is adjusted by the first timing controller 16. For example, in the case of a fluorescent image with a low signal level obtained by irradiating excitation light from the excitation light laser diode 19, adjustment to increase the amplification factor is performed.

  The wavelength band of the excitation light output (emitted) by the excitation light laser diode 19 is set to a wavelength band shorter than the visible light, and the wavelength band of the PDT laser light output (emitted) by the PDT laser diode 26. Is set to a part of the wavelength band of visible light, and the wavelength band of the light transmitted through the excitation light cut filter 20 is set to include the wavelength band of fluorescence or visible light based on the excitation light. Therefore, the excitation light cut filter 20 does not cause a problem such as lack of a blue component in imaging using normal white light from the light source 73 and imaging using PDT laser light from the PDT laser diode 26.

  In the present embodiment, amplification of the image signal output from the image sensor 14 is performed by changing the amplification factor for each type of irradiation light (normally white light and excitation light) (amplification factor adjustment).

  The operation unit 44 includes a first operation button 44a for selecting a first imaging mode based only on white light irradiation, a second operation button 44b for selecting a second imaging mode based on white light irradiation and excitation light irradiation, and imaging. And a freeze operation button 44c for displaying a still image. The operation signals of the first and second operation buttons 44a and 44b are output to the first system control unit 33, and the first system control unit 33 selects the imaging mode (first imaging mode or second imaging mode) selected by the user. Mode). The operation signal of the freeze operation button 44c is output to the second system control unit 71 on the processor 50 side.

  In the first image signal processing unit 17, the luminance information regarding the image signal of the fluorescent image is compared with the luminance threshold value for the fluorescent image, and the comparison result is used as the amplification degree signal. This is performed by being transmitted to the controller 16.

  The brightness detection unit 17d detects luminance information from the image signal regarding the fluorescent image temporarily recorded in the second memory 17c. The comparator 17f compares the luminance information of the image signal relating to the fluorescent image with a preset luminance threshold value for the fluorescent image, and sends the amplification degree signal relating to the amplification factor in the image sensor amplifier 15 to the first timing controller 16 as a comparison result. Output. The amplification degree signal may be used not only for adjusting the amplification factor in the image pickup device amplifier 15 but also for adjusting the degree of noise removal and the emission intensity in the excitation light laser diode 19.

  The first timing controller 16 supplies a timing pulse to each part of the electronic endoscope 10 based on the control of the first system control unit 33, and controls the operation timing of each part. In particular, the first timing controller 16 supplies a timing pulse to the image sensor driver 34 that drives the image sensor 14 and each unit of the first video signal processing unit 17.

  The first video signal processing unit 17 performs the previous image processing such as correlated double sampling processing and noise removal on the image signal in addition to acquiring luminance information for charge accumulation period adjustment and amplification factor adjustment, and performs second processing. This is output to the video signal processing unit 58. Specifically, the image signal amplified by the image pickup device amplifier 15 is subjected to correlated double sampling processing and noise removal, and then is transmitted to the processor 50 as a digital signal and as an analog signal. Output to the grid.

  Noise removal is performed by multiplying the image signals divided into a fluorescent image and a normal white image (or PDT image) and arranged in time series by a weighting coefficient and then averaging. By averaging, noise is reduced, but responsiveness as a moving image is deteriorated (afterimage becomes easy to be noticed). Therefore, the number of weighting coefficients and the number of image signals to be captured for averaging (number of data) To control. In the case of a normal white image (or PDT image), since the brightness is sufficiently ensured, the amplification factor in the image pickup device amplifier 15 is low and the noise is small, so that it is not necessary to perform much noise removal. In the case of a fluorescent image, since the image is dark, the gain in the image pickup device amplifier 15 is set high, and an image including noise is likely to be formed. Therefore, the weighting coefficient of the new image signal is reduced, and the captured image signal is used for averaging. (The averaging calculation is performed including the old image signal) to increase the degree of noise removal compared to the case of the normal white image (or PDT image).

  The image signal output from the first video signal processing unit 17 to the second video signal processing unit 58 is based on the light from the light source 73 corresponding to the operation of the first and second operation buttons 44a and 44b of the operation unit 44. It is performed in a state in which image processing for performing one-screen display of a normal white image and two-screen display of a normal white image based on light from the light source 73 and a fluorescent image based on excitation light from the laser diode 19 is performed. .

  Specifically, when one-screen display (first imaging mode) of a normal white image is selected, the normal white image is written to the first memory 17b, and the scan converter 17e converts the image data in the first memory 17b. Image data corresponding to one normal white image screen is output to the second video signal processing unit 58 by sequentially reading. The same applies to the case where the PDT laser light from the optical sensor 30 is detected and the display is preferentially switched to one-screen display of a PDT image.

  On the other hand, when the two-screen display (second imaging mode) of the normal white image and the fluorescent image is selected, first, the image data of the normal white image and the fluorescent image is stored in the first memory 17b and the second memory 17c. It is written alternately for each field, and image data for one frame (each field) is stored. The scan converter 17e alternately reads out image data from the first memory 17b and the second memory 17c in units of one horizontal scanning line of each image, adjusts the number of pixels to be read by performing pixel mixing processing, and increases the size. The image data for two-screen display in which the normally resized normal white image and the fluorescent image are arranged in parallel in the horizontal direction is generated and output to the second video signal processing unit 58.

  The excitation light LD driver 18 drives the excitation light laser diode 19. Irradiation light (excitation light) output (emitted) by the excitation light laser diode 19 is transmitted through the first optical unit 21, reflected by the beam splitter BS, and transmitted through the first light guide 11 and the light distribution lens 12. Irradiated from the distal end portion of the endoscope 10 toward the subject. The light emission timing of the excitation light laser diode 19 is controlled by the first system control unit 33. For example, the light emission is performed for each field and during a light shielding period in which the liquid crystal shutter 23 blocks light from the light source 73 (normally a white image and Two-screen display of fluorescent image (second imaging mode)). However, the light from the light source 73 may be blocked by the liquid crystal shutter 23, and the excitation light laser diode 19 may be caused to emit light in all fields to display the fluorescent image on one screen.

  The beam splitter BS includes a third incident surface on which light from the first half mirror HM1 is incident, a fourth incident surface on which excitation light emitted from the excitation-light laser diode 19 is incident, a third incident surface, and a fourth incident surface. A laser diode for excitation light, having a second emission surface for emitting light incident from the incidence surface to one end of the first light guide 11 and transmitting light having a relatively long wavelength such as laser light for PDT and visible light Light of a short wavelength such as excitation light emitted from 19 is reflected (see FIG. 3). Accordingly, most of the light incident on the third entrance surface of the beam splitter BS by the light from the light source 73 or the PDT laser light from the PDT laser diode 26 is transmitted and transmitted from the second exit surface to the first light guide 11. It is emitted toward one end of the. Further, most of the light incident on the fourth incident surface of the beam splitter BS by the light from the excitation light laser diode 19 is reflected and emitted from the second exit slope toward one end of the first light guide 11. The However, instead of the beam splitter BS, a half mirror that transmits a part of incident light and reflects the remaining light may be used.

  Under the control of the first system control unit 33, the liquid crystal shutter 23 opens during an irradiation period in which the subject is irradiated with light from the light source 73 and transmits light emitted from the light source 73. The opening / closing operation is performed so that the light emitted from the light source 73 is shielded during the light shielding period in which the excitation light or the PDT laser light from the PDT laser diode 26 is irradiated to the subject. Accordingly, the liquid crystal shutter 23 is opened and closed for each field in the case of two-screen display of a normal white image and fluorescent image (second imaging mode), and the liquid crystal shutter 23 is always in the case of single-screen display of a fluorescent image or a PDT image. In the closed state, when the normal white image is displayed on one screen, the liquid crystal shutter is always opened (first imaging mode).

  Note that when a PDT laser beam is detected by the optical sensor 30 described later, the display is preferentially switched to one-screen display of a PDT image. The first and second operation buttons of the operation unit 44 described above are used to switch between normal white image one-screen display (first imaging mode) and normal white image and fluorescent image two-screen display (second imaging mode). This is performed based on the operation of 44a and 44b.

  In this embodiment, the liquid crystal shutter is used as a device that transmits and blocks normal white light from the light source 73, but other shutter mechanisms may be used.

  In the path for transmitting the digital signal, the digital image signal is converted from parallel data to serial data, and then output to the second video signal processing unit 58 of the processor 50. By performing signal transmission between the electronic endoscope 10 and the processor 50 using serial data, the number of connection pins can be reduced. In an analog signal transmission path, an analog image signal is output to the processor 50 with YC separation.

  The first half mirror HM1 includes a first incident surface on which light from the light source 73 is incident, a second incident surface on which PDT laser light from the PDT laser diode 26 is incident, a first incident surface, and a second incident surface. A first exit surface that emits light incident on the second rod lens 80 toward the second rod lens 80, transmits part of the light incident on the first and second entrance surfaces, and reflects the rest. Therefore, a part of the light incident on the first incident surface of the first half mirror HM1 by the light from the light source 73 is transmitted and emitted from the first emission surface toward the second rod lens 80, and the rest is Reflected by the first half mirror HM1. In addition, a part of the light incident on the second incident surface of the first half mirror HM1 is reflected by the PDT laser light from the PDT laser diode 26 and is emitted from the first emission surface toward the second rod lens 80. The remainder passes through the first half mirror HM1.

  The foot switch 25 is a switch for switching between the light emitting state (ON state) and the light-off state (OFF state) of the PDT laser diode 26 and is disposed under the foot of a user of the electronic endoscope 10 or the like. The PDT laser diode 26 is included in the wavelength band of visible light, has a longer wavelength band than the excitation light laser diode 19, and outputs laser light having a higher intensity than the excitation light laser diode 19 (see FIG. 3). ), PDT is performed based on the irradiation of the affected part with the laser beam. The first, second, and third optical fiber cables (second light guides) 27a, 27b, and 27c guide (transmit) the PDT laser light from the PDT laser diode 26 to the second optical unit 31.

  The first optical fiber cable 27a attached to the PDT laser diode 26 is attached to the optical connector 28 in a removable state. The second optical fiber cable 27b is attached between the optical connector 28 and the second half mirror HM2. The third optical fiber cable 27c is attached between the second half mirror HM2 and the second optical unit 31.

  The second half mirror HM2 transmits part of the incident light and reflects the rest. Accordingly, a part of the light incident on the second half mirror HM2 by the PDT laser light from the PDT laser diode 26 is transmitted and emitted toward the third optical fiber cable 27c, and the rest is the second half mirror. Reflected by the mirror HM2. The distribution ratio of reflection in the second half mirror HM2 is set to be low enough that the reflected light can be detected by the optical sensor 30.

  The PDT laser light from the PDT laser diode 26 and transmitted through the second half mirror HM2 is transmitted through the third optical fiber cable 27c and the second optical unit 31, and is reflected by the first half mirror HM1. The light is irradiated from the tip of the electronic endoscope 10 toward the subject via the beam splitter BS, the first light guide 11 and the light distribution lens 12.

  The PDT laser light from the PDT laser diode 26 and reflected by the second half mirror HM2 passes through the optical filter 29 and reaches the optical sensor 30. The optical filter 29 is a filter whose transmission region is the wavelength band of the light emitted from the PDT laser diode 26, and is intended to prevent the optical sensor 30 from detecting light other than the PDT laser light from the PDT laser diode 26. (The purpose of preventing malfunction of the optical sensor 30).

  The optical sensor 30 is a sensor that detects light emitted from the PDT laser diode 26, and thereby detects that the PDT laser light from the PDT laser diode 26 has entered the electronic endoscope 10. The detected signal is transmitted to the first system control unit 33. The first system control unit 33 displays the one-screen display of the PDT image while the optical sensor 30 detects light. The mode is switched to the mode to be performed, the emission of the excitation light laser diode 21 is stopped, the liquid crystal shutter 23 is closed, and the normal white light from the light source 73 is shielded. Thereby, the light emission state of the PDT laser diode 26 is detected and the mode switching for displaying the PDT image can be performed without an electrical connection between the PDT laser diode 26 and the electronic endoscope 10. It becomes possible.

  Next, each part of the processor 50 will be described. The second video signal processing unit 58 switches between a digital image signal transmitted from the electronic endoscope 10 and an analog image signal and outputs the switched signal to the image processing unit 59.

  In the path for transmitting digital signals, the second video signal processing unit 58 converts the received serial data into parallel data, and then outputs the parallel data to the image processing unit 59. In the path for transmitting with an analog signal, the second video signal processing unit 58 converts the analog image signal into a digital signal again, and then outputs it to the image processing unit 59.

  In the image signal output to the image processing unit 59, luminance information in the image signal is output to the aperture control driver 76a and used for aperture control of the aperture 76c. Further, the image processing unit 59 generates a still image by stopping updating of the memory in the image processing unit 59 for moving image generation in response to the freeze operation by the freeze operation button 44c of the operation unit 44, The signal is output to the signal processing unit 60. The post-stage video signal processing unit 60 performs post-stage image processing such as conversion to a video signal that can be displayed on the image display device 90.

  The second system control unit 71 controls each unit of the processor 50 based on the operation of the operation unit 44 or the like. The second timing controller 72 supplies a timing pulse to each part of the processor 50 and controls the operation timing of each part.

  The light source 73 is a light source device such as a xenon lamp light source, and emits irradiation light (usually white light) that illuminates the subject under the control of the second system control unit 71. The irradiation light emitted from the light source 73 is shielded by the liquid crystal shutter 23 or the light amount is adjusted by the diaphragm 76c, and the condenser lens 51, the first rod lens 24, the liquid crystal shutter 23, the first half mirror HM1, The light is irradiated from the tip of the electronic endoscope 10 toward the subject via the second rod lens 80, the beam splitter BS, the first light guide 11, and the light distribution lens 12.

  The diaphragm 76c is rotated by the diaphragm motor 76b controlled by the diaphragm control driver 76a to adjust the amount of light reaching the condenser lens 51 from the light source 73. The aperture control driver 76a controls the opening degree of the aperture 76c based on the luminance information in the image signal from the image processing unit 59. However, the opening degree of the diaphragm 76c may be adjusted in accordance with the luminance value set manually by the operation of the operation unit 44 by the user.

  In this embodiment, the first light guide 11 that guides the light from the light source 73 is used to guide (transmit) the PDT laser light from the PDT laser diode 26 attached to the electronic endoscope 10. This makes it possible to occupy no forceps channel. Further, in order to detect the PDT laser light from the PDT laser diode 26 and shorten the charge accumulation period for forming the image signal of the image sensor 14 during the detection period, the halation based on the strong light from the PDT laser diode 26 is used. Can be prevented.

  The laser diode 19 provided in the electronic endoscope 10 may or may not be provided on the processor 50 side.

It is a lineblock diagram of an endoscope apparatus in this embodiment. It is the 1st video signal processing part of an electronic endoscope, the 2nd video signal processing part of a processor, and the surrounding block diagram. It is a figure which shows the wavelength band of the light output from the laser diode for excitation light, and the laser diode for PDT. It is a timing chart which shows the output timing of the pulse for charge accumulation period adjustment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Endoscope apparatus 10 Electronic endoscope 11 1st light guide 12 Light distribution lens 13 Objective lens 14 Imaging element 15 Imaging element amplifier 16 1st timing controller 17 1st video signal processing part 17a Memory controller 17b 1st memory 17c 1st 2 memory 17d brightness detector 17e scan converter 17f comparator 18 LD driver for excitation light 19 laser diode for excitation light 20 excitation light cut filter 21 first optical unit 23 liquid crystal shutter 24 first rod lens 25 foot switch 26 PDT laser Diodes 27a, 27b, 27c First, second and third optical fiber cables 28 Optical connector 29 Optical filter 30 Optical sensor 31 Second optical unit 33 First system control unit 34 Image sensor driver 44 Operation Units 44a and 44b First and second operation buttons 44c Freeze operation buttons 50 Processor 51 Condensing lens 53 Optical unit 58 Second video signal processing unit 59 Image processing unit 60 Subsequent video signal processing unit 71 Second system control unit 72 Second Timing controller 73 Light source 76a Aperture control driver 76b Aperture motor 76c Aperture 80 Second rod lens 90 Image display device BS Beam splitter HM1, HM2 First and second half mirrors

Claims (8)

A first light guide for transmitting first irradiation light from the light source device;
A second light guide that transmits second irradiation light for PDT to the first light guide;
An electronic endoscope of an endoscope apparatus comprising: an imaging element that captures an image of a subject irradiated with at least one of the first irradiation light and the second irradiation light via the first light guide.   2. The electron according to claim 1, further comprising a shutter capable of switching between transmission and shielding of light from the first irradiation light for switching light irradiated through the first light guide. Endoscope. An optical sensor for detecting the second irradiation light;
The electronic endoscope according to claim 2, wherein when the optical sensor detects the second irradiation light, the shutter blocks light from the first irradiation light.   The charge accumulation period for obtaining an image signal in the image sensor is set to be short when the subject irradiated with the second irradiation light through the first light guide is imaged. The electronic endoscope as described.   The electronic endoscope according to claim 1, wherein the first irradiation light is white light, and the second irradiation light is PDT laser light. The first incident surface on which the first irradiation light from the light source device is incident, the second incident surface on which the second irradiation light from the light source device for PDT is incident, the first incident surface, and the second incident surface. A first light guide member having a first emission surface for emitting light;
A first light guide that emits light that is emitted from the first emission surface of the first light guide member to one end and the light that is incident on the one end from the other end;
An electronic endoscope for an endoscope apparatus, comprising: an imaging element that images a subject irradiated with light emitted from the other end of the first light guide. A shutter provided on the first incident surface side and capable of shielding the first irradiation light;
A second light guide for guiding the second irradiation light to the second incident surface of the first light guide member;
An optical sensor for detecting the second irradiation light;
When the optical sensor detects the second irradiation light, the first irradiation light is shielded, the second irradiation light is guided to the one end of the first light guide, and the optical sensor detects the second irradiation light. A control unit that controls opening and closing of the shutter so that the first irradiation light is transmitted through the shutter and guided to the one end of the first light guide when no light is detected. The electronic endoscope according to claim 6, wherein the electronic endoscope is characterized in that: An excitation light source device that emits excitation light for fluorescence observation;
A third incident surface disposed between the first light guide member and the one end portion of the first light guide, on which light from the first light guide member is incident, and a fourth surface on which the excitation light is incident. A second light guide member having an incident surface, and a second light emitting surface that emits light incident from the third incident surface and the fourth incident surface to the one end portion of the first light guide. The electronic endoscope according to claim 6, wherein the electronic endoscope is characterized in that:

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