JP2009095538A - Electronic endoscope of endoscope apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic endoscope of an endoscope apparatus allowing an observation using a light source different from that of a regular white light without greatly changing a processor side. <P>SOLUTION: This electronic endoscope 10 of the endoscope apparatus 1 includes: a light guide 11 for transmitting a regular white light from a light source 73 of a processor 50 and an excitation light; a light emission section (a laser diode 19 for the excitation light) for emitting the excitation light; and an imaging device 14 for imaging a subject to which either of the regular white light or the excitation light is applied via the 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 observation using a light source different from normal white light.

  Conventionally, an endoscope that switches excitation light for obtaining a fluorescent image and normal white light for obtaining a normal white image to irradiate a subject as illumination light and images reflected light (fluorescence in the case of excitation light) A device has been proposed.

Patent Document 1 discloses an endoscope apparatus that displays a fluorescent image and normal white light on two screens.
JP 2006-6833 A

  However, in Patent Document 1, it is necessary to provide a processor including a light source for excitation light. Providing a new processor, which is usually less frequently replaced, places a great burden on the user.

  Accordingly, an object of the present invention is to provide an electronic endoscope of an endoscope apparatus that can perform observation using a light source different from normal white light without greatly changing the processor side.

  An electronic endoscope of an endoscope apparatus according to the present invention includes a light guide that transmits first illumination light and second illumination light from a light source device, a light emitting unit that emits second illumination light, and a first light source. An imaging device that images a subject irradiated with either illumination light or second illumination light via a light guide is provided.

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

  Preferably, the image signal obtained by the imaging device is amplified at a different amplification factor in the case of the first illumination light and in the case of the second illumination light before being output to the processor that performs image processing. It includes at least one of an element amplifier and a video signal processing unit that performs noise removal with different degrees of noise removal in the case of the first illumination light and the case of the second illumination light.

  Preferably, the first image obtained by imaging the subject irradiated with the first illumination light with the imaging device and the second image obtained by imaging the subject irradiated with the second illumination light with the imaging device. A video signal processing unit that performs image processing for performing two-screen display with an image and outputs the image to a processor that performs other image processing is provided.

  Preferably, the light source further includes an excitation light cut filter that cuts excitation light for obtaining a fluorescent image out of light incident on the imaging device, the first illumination light is white light, and the second illumination light is Excitation light.

  An electronic endoscope of an endoscope apparatus according to the present invention transmits a shutter that can block first illumination light from a light source device, a light emitting unit that emits second illumination light, and light incident from one end. A light guide that is emitted from the other end, a light guide that is provided between one end of the light guide and the shutter, and guides the first illumination light and the second illumination light to the one end of the light guide, and a shutter. And a control unit that controls the light emitting unit and performs switching control so that light incident on one end of the light guide is either the first illumination light or the second illumination light.

  As described above, according to the present invention, it is possible to provide an electronic endoscope of an endoscope apparatus capable of observation using a light source different from normal white light without largely changing the processor side.

  Embodiments according to the present invention will be described below 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 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, and an LD driver. 18, a laser diode (LD) 19, an excitation light cut filter 20, an optical unit 21, a liquid crystal shutter 23, a rod lens 24, a first system control unit 33, an image sensor driver 34, an operation unit 44, and a beam splitter BS The normal white light from the light source 73 on the light source device side such as the processor 50 or the excitation light from the laser diode 19 of the electronic endoscope 10 is irradiated through the light distribution lens 12 into the body as the object, and the objective lens An image is picked up by the image pickup device 14 via 13.

  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, An aperture motor 76b and an aperture 76c are provided, illumination light (usually white light) and electric power are supplied to the electronic endoscope 10, and image processing of the image signal of the subject imaged by the electronic endoscope 10 (2 Other image processing different from the image processing for screen display is performed, and 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 light guide 11 transmits normal white light from the light source 73 or excitation light from the laser diode 19 to the distal end portion of the electronic endoscope 10. The light transmitted by the light guide 11 is irradiated to the subject via the light distribution lens 12.

  The imaging device 14 captures, as an optical image, reflected light (subject image, fluorescence when irradiated with excitation light from the laser diode 19) incident on the subject incident through the objective lens 13 and the excitation light cut filter 20. The excitation light cut filter 20 removes light in a short wavelength band including the wavelength band of light emitted from the 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 laser diode 19, adjustment to increase the amplification factor is performed.

  The wavelength band of the excitation light output (emitted) by the laser diode 19 is set to a wavelength band shorter than visible light, and the wavelength band of the light transmitted through the excitation light cut filter 20 is fluorescent or visible based on the excitation light. It is set to include the wavelength band of light. For this reason, 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.

  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 illumination light (normal white light and excitation light) (amplification factor adjustment).

  The operation unit 44 includes a first operation button 44a for selecting a first imaging mode using only white light illumination, a second operation button 44b for selecting a second imaging mode using white light illumination and excitation light illumination, 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.

  Specifically, by the memory controller 17a controlled by the first timing controller 16, among the image signals from the image sensor amplifier 15, those relating to the normal white image are temporarily recorded in the first memory 17b, and those relating to the fluorescent image are The data is 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 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 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 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 pre-stage image processing such as correlated double sampling processing and noise removal on the image signal in addition to obtaining luminance information for gain adjustment. 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.

  The noise removal is performed by averaging the image signals divided into a fluorescent image and a normal white image and arranged in time series after multiplying by a weighting coefficient. 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, since the brightness is sufficiently secured, 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 as compared with the case of a normal white 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. . Therefore, it is not necessary to perform image processing for two-screen display on the processor 50 side.

  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.

  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 LD driver 18 drives the laser diode 19. Illumination light (excitation light) output (emitted) by the laser diode 19 is transmitted through the optical unit 21 and reflected by the beam splitter BS, and the distal end portion of the electronic endoscope 10 via the light guide 11 and the light distribution lens 12. It is irradiated toward the subject. The light emission timing of the laser diode 19 is controlled by the first system control unit 33, and, for example, the light is emitted for each field and in a light shielding period in which the liquid crystal shutter 23 blocks light from the light source 73 (second imaging mode).

  The beam splitter BS transmits light having a relatively long wavelength such as visible light, and reflects light having a short wavelength such as excitation light emitted from the laser diode 19 (see FIG. 3). Therefore, most of the light incident on the beam splitter BS as light from the light source 73 is transmitted and guided toward one end of the light guide 11. Further, most of the light incident on the beam splitter BS by the light from the laser diode 19 is reflected and guided toward one end of the light guide 11. 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.

  The liquid crystal shutter 23 is opened during an illumination period (one field) in which the subject is illuminated with light from the light source 73 based on the control of the first system control unit 33, and transmits the 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 (one field) in which the subject is illuminated with light from the light source. Therefore, for each field, an image obtained by imaging with the imaging device 14 is switched between a normal white image and a fluorescent image (second imaging mode).

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

  When subject irradiation using the laser diode 19 is not performed (in the case of one-screen display of a normal white image based on the light from the light source 73 (first imaging mode)), the liquid crystal shutter 23 is kept open. The In this case, an image obtained by imaging with the imaging element 14 is a normal white image in all fields.

  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.

  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 illumination light (usually white light) that illuminates the subject under the control of the second system control unit 71. The illumination 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 rod lens 24, the liquid crystal shutter 23, the beam splitter BS, the light guide 11, The light is irradiated toward the subject from the distal end portion of the electronic endoscope 10 via 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 the present embodiment, by providing the laser diode 19 on the electronic endoscope 10 side, it becomes possible for the processor 50 having no laser diode to observe a fluorescence image by excitation light from the laser diode. In addition, since image processing related to display switching such as two-screen display between a fluorescent image and a normal white image is performed on the electronic endoscope 10 side and transmitted to the processor 50, the design considering compatibility with the processor 50 is adopted. It has the advantage of being easy to do.

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 range | band of the light output from a laser diode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Endoscope apparatus 10 Electronic endoscope 11 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 2nd memory 17d Brightness detection unit 17e Scan converter 17f Comparator 18 LD driver 19 Laser diode 20 Excitation light cut filter 21 Optical unit 23 Liquid crystal shutter 24 Rod lens 33 First system control unit 34 Image sensor driver 44 Operation unit 44a, 44b First, Second operation button 44c Freeze operation button 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 2 second timing controller 73 sources 76a diaphragm control driver 76b stop motor 76c squeeze 90 image display device BS beam splitter

Claims (6)

A light guide for transmitting the first illumination light and the second illumination light from the light source device;
A light emitting unit for emitting the second illumination light;
An electronic endoscope for an endoscope apparatus, comprising: an imaging element that captures an image of a subject irradiated with either the first illumination light or the second illumination light via the light guide.   2. The electronic device according to claim 1, further comprising a shutter capable of switching between transmission and shielding of light from the first illumination light for switching of illumination light irradiated through the light guide. Endoscope.   An image pickup device amplifier that amplifies the image signal obtained by the image pickup device at a different amplification factor in the case of the first illumination light and the case of the second illumination light before being output to a processor that performs image processing. And at least one of image signal processing units for performing noise removal with different degrees of noise removal in the case of the first illumination light and the case of the second illumination light. Endoscope.   A first image obtained by imaging the subject irradiated with the first illumination light with the imaging device, and a second image obtained by imaging the subject irradiated with the second illumination light with the imaging device. The electronic endoscope according to claim 1, further comprising: a video signal processing unit that performs image processing for performing two-screen display and outputs to a processor that performs other image processing. Of the light incident on the image sensor, further comprising an excitation light cut filter for cutting excitation light for obtaining a fluorescence image,
The electronic endoscope according to claim 1, wherein the first illumination light is white light, and the second illumination light is the excitation light. A shutter capable of shielding the first illumination light from the light source device;
A light emitting unit that emits second illumination light;
A light guide that transmits light incident from one end and exits from the other end;
A light guide provided between the one end of the light guide and the shutter and guiding the first illumination light and the second illumination light to the one end of the light guide;
A control unit that controls the shutter and the light emitting unit, and controls switching so that light incident on the one end of the light guide is either the first illumination light or the second illumination light; An electronic endoscope of an endoscope apparatus characterized by the above.

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