JP2012232063A - Endoscopic device - Google Patents

Abstract

An image suitable for endoscopic diagnosis is obtained by suppressing the occurrence of halation while maintaining the quality of an observed image.
In an endoscope apparatus 100, an observation window 41 and a pair of illumination windows 43A and 43B are arranged at the distal end of an endoscope insertion portion 25 with the observation window 41 interposed therebetween. The first light source LD1 supplies illumination light to the first illumination window 43A arranged on one side of the observation window, and the second light source LD2 is supplied to the second illumination window 43B arranged on the other side. Provides illumination light. The halation occurrence region of the first captured image is a second captured image of the first captured image captured by dimming the first light source and the second captured image captured by dimming the second light source. When the number is larger than the halation occurrence area of the captured image, the target light amount value set for the first light source is decreased, and when it is smaller, the light amount control for decreasing the target light amount value set for the second light source is performed.
[Selection] Figure 1

Description

  The present invention relates to an endoscope apparatus.

  When observing the inside of a patient's body cavity using an endoscope apparatus, the surface of the body cavity close to the illumination window arranged at the distal end of the endoscope insertion portion has a higher illumination light intensity and an increased amount of reflected light. Further, since the body cavity surface is wet with a body fluid or the like, it is in a state of being easily mirror-reflected. For this reason, halation (out-of-brightness) on the body cavity surface is likely to occur in the obtained captured image. This is because the amount of light received by the image sensor provided at the tip of the endoscope insertion portion exceeds the dynamic range. The presence of halation makes it difficult to see the observation image displayed on the monitor. In particular, when the object to be observed is a depression or a raised portion, halation inevitably occurs in the observation region of interest, and endoscopic observation or endoscopy May interfere with mirror diagnosis.

  Therefore, in order to suppress the halation that leads to such troubles, the presence or absence of halation is detected based on the luminance histogram of the observation image obtained by the image sensor, and when halation is detected, it is provided on the light emission side of the illumination. A method has been proposed in which the aperture state of the iris (iris) is controlled to reduce the amount of illumination light and suppress halation (for example, Patent Document 1).

JP 2002-58640 A

  However, if the halation occurring in the observation image is to be eliminated by the overall illumination light amount reduction control, the amount of decrease in the light amount increases and the observation image becomes dark. Therefore, there is an endoscope apparatus in which the amount of illumination light can be locally changed to change to an arbitrary light amount distribution. According to this endoscope apparatus, the light intensity distribution of the illumination light can be changed so that the local brightness and darkness of the observed image is made uniform over the entire screen, and the amount of light emitted from the illumination window close to the part where the halation occurs is selected. Reduction can be controlled. However, the halation occurrence region of the observation image and the position of the illumination window do not necessarily have a correlation, and halation often occurs due to the shape of the observation target. Therefore, it is a fact that it is still difficult to eliminate halation without degrading the quality of the observed image.

  An object of the present invention is to provide an endoscope apparatus that can obtain an image suitable for endoscopic diagnosis by suppressing the occurrence of halation while maintaining the quality of an observation image.

The present invention has the following configuration.
An endoscope apparatus in which an observation window and a pair of illumination windows are arranged across the observation window at the tip of an endoscope insertion portion to be inserted into a subject,
The pair of illumination windows comprises a first illumination window disposed on one side of the observation window, and a second illumination window disposed on the other side,
A first light source for supplying illumination light to the first illumination window;
A second light source for supplying illumination light to the second illumination window;
An imaging device that images the subject through the observation window and outputs a captured image signal of the subject; and a halation detection unit that detects a halation occurrence region from luminance information of the captured image signal;
Control means for individually controlling the amount of light emitted from the first light source and the second light source according to each target light amount value set for each of the first light source and the second light source;
With
The first picked-up image with respect to the first picked-up image taken by dimming the first light source and the second picked-up image picked up by dimming the second light source. When the halation occurrence area is larger than the halation occurrence area of the second captured image, the target light amount value set for the first light source is decreased, and when the halation occurrence area is less, the target set for the second light source An endoscope apparatus that performs light amount control to reduce a light amount value.

  According to the endoscope apparatus of the present invention, an image suitable for endoscopic diagnosis can be obtained by suppressing halation while maintaining the quality of an observation image.

It is a figure for describing an embodiment of the present invention, and is a lineblock diagram of an endoscope apparatus showing each apparatus to which an endoscope and an endoscope are connected. It is an external view which shows the specific structural example of an endoscope apparatus. It is an expansion perspective view of an endoscope front-end | tip part. It is a flowchart which shows the procedure which suppresses halation and displays an image, when halation arises in the image | photographed image. It is explanatory drawing which shows an example of an observation image. It is explanatory drawing which shows the brightness | luminance histogram of an observation image. It is a flowchart which shows the specific procedure of halation minimization light source control shown in FIG. (A) is an explanatory view showing an example of an image B, and (B) is an explanatory view showing an example of an image C. It is a flowchart which shows the procedure of the optimization image generation process. (A) is a figure which shows a mode that the image A which is an observation image was divided into a plurality of areas, and (B) is a halation occurrence area A1 when the halation occurrence area is defined in units of blocks and a background other than A1 It is explanatory drawing which shows area | region A2. It is explanatory drawing which shows an example of the image E. FIG. It is explanatory drawing which shows typically a mode that the brightness | luminance information H1 and the brightness | luminance information H2 are synthesize | combined combining a block position and a synthesized image is produced | generated. It is explanatory drawing which shows the synthesized image by which the halation was suppressed. It is a block diagram of the light source device which radiate | emits multiple types of wavelength light. It is a graph of the illumination light spectrum produced | generated with the emitted light from a 1st light source part and a 2nd light source part, and radiate | emitted from the illumination window of an endoscope front-end | tip part.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram for explaining an embodiment of the present invention. FIG. 1 is a configuration diagram of an endoscope apparatus representing an endoscope and each apparatus to which the endoscope is connected. FIG. 2 is a specific example of the endoscope apparatus. It is an external view which shows a structural example.
As shown in FIG. 1, the endoscope apparatus 100 includes an endoscope 11, a control device 13, a display unit 15 such as a monitor, and an input unit 17 such as a keyboard and a mouse that input information to the control device 13. Is provided. The control device 13 includes a light source device 19 and a processor 21 that performs signal processing of a captured image.

  The endoscope 11 includes a main body operation unit 23 and an insertion unit 25 that is connected to the main body operation unit 23 and is inserted into a subject (body cavity). A universal cord 27 is connected to the main body operation unit 23. Is done. The distal end of the universal cord 27 is connected to the light source device 19 through a light guide (LG) connector 29A, and is connected to the processor 21 through a video connector 29B.

  As shown in FIG. 2, the main body operation unit 23 of the endoscope 11 has buttons for performing suction, air supply, and water supply on the distal end side of the insertion unit 25, a shutter button at the time of imaging, and a rest that will be described in detail later. Various operation buttons 31 such as an image shooting button 30 are provided along with a pair of angle knobs 33.

  The insertion portion 25 is composed of a flexible portion 35, a bending portion 37, and a distal end portion (endoscope distal end portion) 39 in order from the main body operation portion 23 side. The bending portion 37 is remotely bent by turning the angle knob 33 of the main body operation portion 23, and thereby the tip portion 39 can be directed in a desired direction.

  As shown in FIG. 1 and FIG. 3 which is an enlarged perspective view of the endoscope front end portion 39, the endoscope front end portion 39 includes an observation window 41 of the imaging optical system and a pair of illumination windows 43A of the illumination optical system. , 43B are arranged. These illumination windows 43A and 43B are arranged on both sides of the observation window 41. Reflected light from the subject due to illumination light emitted from each of the illumination windows 43A and 43B is photographed as an observation image through the observation window 41 by the image sensor 45 (see FIG. 1). The captured observation image is subjected to appropriate image processing and displayed on the display unit 15 connected to the processor 21.

  The imaging optical system includes an imaging element 45 such as a CCD (Charge Coupled Device) type image sensor or a CMOS (Complementary Metal Oxide Semiconductor) type image sensor, and an optical member 47 such as a lens for forming an observation image on the imaging element 45. Have The observation image formed and captured on the light receiving surface of the image sensor 45 is converted into an electric signal and input to the image signal processing unit 53 of the processor 21 through the signal cable 51, and the image signal (imaging image) is input to the image signal processing unit 53. Image signal).

  On the other hand, the illumination optical system includes a light source device 19, a pair of optical fibers 55A and 55B connected to the light source device 19 via the LG connector 29A, and wavelength conversion members disposed at the light emitting ends of the optical fibers 55A and 55B, respectively. 57A, 57B.

  The light source device 19 includes laser light sources LD1 and LD2 and a light source control unit 59 that individually drives and controls the laser light sources LD1 and LD2. Light emitted from the laser light sources LD1 and LD2 is introduced into the optical fibers 55A and 55B via the LG connector 29A.

  The laser light sources LD1 and LD2 are blue light emitting semiconductor light sources having a central wavelength of 445 nm. As the laser light sources LD1 and LD2, for example, a broad area type InGaN laser diode can be used.

  The light source controller 59 controls the output light intensity, lighting timing, and the like of the laser light sources LD1 and LD2. The respective output lights of the laser light sources LD1 and LD2 are transmitted to the endoscope distal end portion 39 through the endoscope insertion portion 25 through the optical fibers 55A and 55B, and are irradiated to the wavelength conversion members 57A and 57B. Then, the wavelength conversion members 57A and 57B emit illumination light, which is a combination of the output light from the laser light sources LD1 and LD2 and the emitted light wavelength-converted by the wavelength conversion members 57A and 57B, to the illumination windows 43A and 43B, respectively. . That is, light of arbitrary intensity can be emitted from the illumination windows 43A and 43B at an arbitrary timing by individual control of the laser light sources LD1 and LD2 by the light source controller 59.

  The wavelength conversion members 57A and 57B absorb a part of the blue laser light emitted from the laser light sources LD1 and LD2 and emit a plurality of types of phosphors (for example, YAG-based phosphors or BAM (BaMgAl10O37) that excite and emit green to yellow light. ) And the like. The wavelength conversion members 57A and 57B generate white light in which the blue laser light from the laser light sources LD1 and LD2 and the green to yellow excitation light obtained by wavelength conversion of the blue laser light are combined. Since the white light has a broad spectrum, the color rendering property of the observation image is improved.

  Here, the white light referred to in the present specification is not limited to the one that strictly includes all wavelength components of visible light, and examples thereof include R (red), G (green), and B (blue) that are reference colors. As long as it includes light in a specific wavelength band, for example, light including a wavelength component from green to red, light including a wavelength component from blue to green, and the like are broadly included.

  The processor 21 includes an endoscope control unit 69, the above-described imaging signal processing unit 53 that generates a video signal, a memory 71 as a storage unit that stores the imaging signal and various information, and an image processing unit 73. Yes. The endoscope control unit 69 performs appropriate image processing on the image data of the observation image output from the imaging signal processing unit 53 by the image processing unit 73 and causes the display unit 15 to display the processed image data. In addition, a control signal is output to the light source controller 59 of the light source device 19 so that a desired amount of illumination light is emitted from each of the illumination windows 43A and 43B. The endoscope control unit 69 is connected to a network such as a LAN (not shown) and controls the entire endoscope apparatus 100 such as distributing information including image data.

  In addition, a foot switch 61, which will be described in detail later, is connected to the processor 21 as one of the input units 17.

Next, control for suppressing the occurrence of halation when halation occurs in the observation image acquired by the endoscope apparatus 100 having the above-described configuration will be described.
FIG. 4 is a flowchart showing a procedure for displaying an image while suppressing halation when halation occurs in the captured image. First, the operator of the endoscope apparatus 100 inserts the endoscope insertion portion 25 into the body cavity of the patient, and images and observes the observation site with the imaging element 45 disposed at the endoscope distal end portion 39. An image (image A) is obtained (S11).

  FIG. 5 shows an example of an observation image. In the observed image 81, a halation 83 is generated in a part of the body cavity. Next, a halation occurrence region is extracted from this observation image 81 (S12). In the halation occurrence region, as shown in FIG. 6, an endoscope control unit 69 (see FIG. 1) as a halation detection unit causes the image processing unit 73 to obtain a luminance histogram of the observation image 81 and presents a maximum luminance value. Obtained by extracting pixels. That is, the pixel having the maximum luminance value of the captured image obtained by quantizing the captured image signal output from the image sensor 45 is detected as a halation generation region.

  It should be noted that not only the maximum luminance value but also the halation occurrence region may be included in the vicinity of the maximum luminance value, for example, including pixels of 80% or more or 90% or more of the maximum luminance value. In addition, among the extracted pixels, appropriate noise removal such as selectively extracting a plurality of pixels having the maximum luminance value adjacent to each other may be performed.

  The endoscope control unit 69 extracts a halation-minimized light source for minimizing the generated halation when the halation occurrence area obtained by extracting the pixel having the maximum luminance value is equal to or greater than a predetermined number of pixels. Control is performed (S14). If the predetermined number of pixels is not reached, it is assumed that no halation has occurred, and the observation image 81 is displayed on the display unit 15 (S15).

When halation occurs, halation minimization light source control is performed as follows. FIG. 7 is a flowchart showing a specific procedure of halation minimization light source control (S14) shown in FIG.
First, the endoscope control unit 69 as a control means for performing light amount control outputs the laser light source LD1 so that the light emitted from the right (R side) illumination window 43A is reduced by a predetermined light amount. The light source controller 59 controls the intensity to decrease. Then, in the illumination windows 43A and 43B, only the light emitted from the illumination window 43A is dimmed. In this state, the site to be observed is imaged by the imaging element 45 to obtain an observation image (image B: first captured image) (S21).

  Next, the endoscope control unit 69 reduces the output intensity of the laser light source LD2 to the light source control unit 59 so that the light emitted from the left (L side) illumination window 43B is reduced by a predetermined light amount. Let me control. Then, only the light emitted from the illumination window 43B is reduced in the illumination windows 43A and 43B. In this state, the site to be observed is imaged by the imaging element 45 to obtain an observation image (image C: second captured image) (S22).

  FIG. 8A shows an example of the image B, and FIG. 8B shows an example of the image C. When the halation 83 generated in the observation image 81 occurs on both the left and right sides of the screen, it is related to the arrangement of the illumination windows 43A and 43B arranged on the left and right sides of the observation window 41. It may occur due to irradiation light. In other words, the halation occurring in the right side foreground area of the observation image 81 is caused by the light emitted from the illumination window 43A disposed on the right side of the observation window 41, and the halation in the foreground area on the left side of the screen is caused by the left side illumination. It may occur due to light emitted from the window 43B.

  For this reason, as shown in FIG. 8A, the halation 83A generated in the near-right region on the right side of the screen of the observation image 81 is reduced by reducing the light emitted from the illumination window 43A. In this case, as shown in FIG. 8B, even if the light emitted from the illumination window 43B is reduced, the size of the region where the halation 83B occurs is not particularly changed.

  On the contrary, the halation occurring in the foreground area on the left side of the observation image 81 is reduced even if the emission light from the illumination window 43B is reduced by reducing the emission light from the illumination window 43B. The size of the halation occurrence area is not particularly changed.

  If the above characteristics are used, the generated halation can be suppressed by light source control. Returning to FIG. 7, the endoscope control unit 69 obtains a luminance histogram for the images B and C obtained by taking the light emitted from the illumination windows 43 </ b> A and 43 </ b> B with light reduction control, and generates halation. A region is extracted in the same manner as described above (S23).

  Then, the endoscope control unit 69 compares the sizes of the halation occurrence areas of the images B and C (S24), and only the emitted light from the right illumination window 43A is dimmed and the halation of the image B is taken. If the generation area is larger than the halation generation area of the image C taken by dimming only the light emitted from the left illumination window 43B, the light emission from the left illumination window 43B is controlled to be dimmed (S25).

  On the contrary, the halation occurrence region of the image B photographed by dimming only the light emitted from the right illumination window 43A is more than the halation occurrence region of the image C photographed by dimming only the light emitted from the left illumination window 43B. If it is larger, the light emitted from the left illumination window 43B is dimmed (S25). If there is no difference in the halation occurrence area between the images B and C, the endoscope control unit 69 stops the minimized light source control although not shown in the drawing, assuming that it is out of the control range.

  In order to perform dimming control on the light emitted from the left illumination window 43B, the endoscope control unit 69 causes the light source control unit 59 to reduce the target light amount value for controlling the light emission amount of the laser light source LD2 by a predetermined level. To do. Similarly, in order to reduce the emission light from the right illumination window 43A, the endoscope control unit 69 sets the target light amount value for controlling the light emission amount of the laser light source LD1 to the light source control unit 59 by a predetermined level. Do it by decreasing.

  Here, in the control for reducing the target light amount value, instead of reducing the predetermined level, the operator of the endoscope may arbitrarily set the reduction range. For example, the foot switch 61 shown in FIG. 2 functions as a light amount change switch that changes the emitted light amount of the laser light sources LD1 and LD2, and the amount of decrease in the target light amount value is determined according to the input operation from the foot switch 61. Also good.

  According to this configuration, the degree of reduction of the generated halation can be sequentially changed by operating the foot switch 61, and the optimum light amount control can be easily performed even during the operation of the endoscope.

  Next, the endoscope control unit 69 drives to emit light in a state where the target light amount value for one of the laser light sources LD1 and LD2 is decreased as described above, and causes the light source control unit 59 to emit light. In this state, the site to be observed is imaged by the imaging element 45 to obtain an observation image (image D: third captured image) (S27).

  Then, the halation occurrence area of the obtained image D is extracted in the same manner as described above (S28), and it is determined whether the halation occurrence area is equal to or smaller than a predetermined area (S29). If the halation occurrence area exceeds the predetermined area, it is determined that halation minimization light source control is still insufficient, and the processing from S21 is performed again. That is, the above-described light amount control is repeated until the halation occurrence area becomes equal to or smaller than a predetermined area.

  On the other hand, when the halation occurrence area is equal to or smaller than the predetermined area, the light source control is performed by setting the target light amount value subjected to the decrease control to the next target light amount value. That is, the endoscope control unit 69 drives the laser light sources LD1 and LD2 by reducing the target light amount value set based on the luminance information of the photographed observation image by the amount of dimming control by the halation minimizing light source control. (S30).

  According to the above-mentioned halation minimization light source control, the halation generated in the observation image can be minimized by the control of the amount of light emitted from the light source, and the occurrence of halation at the target site in the observation image and the difficulty of observation are suppressed. Therefore, an observation image suitable for endoscopic observation and endoscopic diagnosis can be obtained.

  In addition, the above-described halation minimization light source control performs the above-described reduction control of the target light amount value when the still image shooting button 30 (see FIGS. 1 and 2) for inputting the still image shooting timing is pressed. It may be a thing. According to this, when the still image shooting button 30 is pressed and the still image shooting is performed, the halation occurrence area where the image information of the affected part disappears can be kept to a minimum range, and a good still image can be obtained. Can be obtained.

  The above-mentioned halation minimization light source control is for dimming control of one of the laser light sources LD1 and LD2, but in that case, the observation image may become dark due to insufficient light quantity as the entire observation image. is there. Therefore, the endoscope control unit 69 may increase / decrease the respective target light amount values for the laser light sources LD1 and LD2 so that the sum of the emitted light amounts of the laser light sources LD1 and LD2 is constant. That is, the amount of illumination light can be kept constant by performing the light-intensity control of the other laser light source as much as the light-intensity control of one laser light source.

  In this case, if the amount of reduction in the halation occurrence area due to the dimming control of one laser light source is greater than the amount of new halation generation due to the light increase control of the other laser light source, the halation occurrence area of the entire observation image is reduced. it can.

  After performing the above-described halation minimization light source control, as shown in FIG. 4, it is determined whether the size of the halation occurrence area has become a predetermined level or less (S16). Image display (S15) is performed and the process ends. If it is insufficient, an optimized image generation process is performed (S17).

  FIG. 9 shows a flowchart showing the procedure of the optimized image generation process. In the optimized image generation processing, first, the endoscope control unit 69 extracts the halation occurrence region A1 of the image A (or image D) that is the observation image in the same manner as described above, and the extracted region A1 and region A background area A2 other than A1 is determined (S31).

  FIG. 10A is a diagram showing a state in which the image A, which is an observation image, is divided into a plurality of areas, and FIG. 10B is a halation generation area A1 when the generation area of the halation 83 is defined in units of blocks, and A1 It is a figure which shows background area | region A2 other than. As an example, the block division is 4 × 4 equal division (16 blocks in total up to (1,1), (1,2),..., (4,4)), but is not limited thereto. Any number of divisions can be used.

  Then, the endoscope control unit 69 reduces the light amount from the target light amount to the laser light source that has been subjected to the dimming control performed in S25 or S26 in the halation minimizing light source control described in FIG. The observed part is imaged by the imaging element 45 to obtain an observation image (image E: fourth captured image) (S32).

  An example of the image E at this time is shown in FIG. In the image E, since the endoscope control unit 69 performs the dimming control of the laser light source LD1 so that the light emitted from the right illumination window 43A (see FIGS. 1 and 3) is dimmed, it occurs in the image A. The halation 83 that has been reduced. It is preferable to perform dimming control until the halation 83 disappears completely. In the example of the image E, the laser light source LD2 is controlled to be brightened by the amount that the laser light source LD1 is dimmed, and the light emitted from the left illumination window 43B is lightened. As a result, a new halation 83C occurs in the image E.

  Next, the endoscope control unit 69 extracts the luminance information H1 of the image E corresponding to the block that is the halation occurrence area A1 in the image A, and the extracted luminance information H1 is stored in the memory 71 (FIG. 1) (S33). Further, the endoscope control unit 69 extracts the luminance information H2 for the background area A2 from the image A (image D) described above, and stores the extracted luminance information H2 in the memory 71 (S34).

  Then, as shown in FIG. 12, the endoscope control unit 69 generates a synthesized image obtained by synthesizing the luminance information H1 and the luminance information H2 stored in the memory 71 by matching the block positions (S35). The luminance information H1 includes information on the luminance distribution of the area A1 in which the halation is reduced (or disappeared), and the luminance information H2 includes the background area A2 that is an area in which the halation of the image A does not occur. Contains luminance distribution information. By combining both pieces of luminance information H1 and H2, a combined image in which halation is suppressed is generated as shown in FIG.

  At this time, a new halation 83C has occurred in the image E shown in FIG. 11. However, since the image E uses only the luminance information H1 for the area A1 for generating a composite image, the appearance of the halation 83C is included in the composite image. There is no effect.

  After performing the above optimized image generation processing, as shown in FIG. 4, a composite image without halation is displayed on the display unit 15 (S15).

As described above, even when halation minimization light source control is performed, even if halation cannot be sufficiently minimized, optimized image generation processing can be performed and halation can be reliably suppressed by image synthesis.
As a result, it is possible to suppress the occurrence of halation while maintaining the quality of the observation image, and obtain an image suitable for endoscopic diagnosis.

<Modification>
Next, a modified example in which the configuration of the light source device 19 is changed will be described.
FIG. 14 shows a configuration diagram of a light source device that emits light of a plurality of types of wavelengths. A light source device 19A of the present modification includes a first light source unit 87 that introduces illumination light into the optical fiber 55A, a second light source unit 89 that introduces illumination light into the optical fiber 55B, a first light source unit 87, and And a light source control unit 59 that controls the second light source unit 89.

  The first light source unit 87 combines and outputs the laser light source LD1-A having a central wavelength of 445 nm, the laser light source LD1-B having a central wavelength of 405 nm, and the laser light sources LD1-A and LD1-B. And a combiner 91.

  Similarly to the first light source unit 87, the second light source unit 89 includes a laser light source LD2-A having a central wavelength of 445 nm, a laser light source LD2-B having a central wavelength of 405 nm, and a combiner 93.

  FIG. 15 shows a graph of an illumination light spectrum that is generated from the light emitted from the first light source unit 87 and the second light source unit 89 and emitted from the illumination window at the distal end portion of the endoscope. The illumination light spectrum by the laser light sources LD1-A and LD2-A is represented by a profile P1, and the illumination light profile by the laser light sources LD1-B and LD2-B is represented by a profile P2.

  As described above, the blue laser beam having the center wavelength of 445 nm excites the wavelength conversion members 57A and 57B disposed at the light emitting ends of the optical fibers 55A and 55B of the endoscope distal end portion 39 to emit fluorescence. Some of the blue laser light passes through the wavelength conversion members 57A and 57B as it is. As a result, white light is generated.

  On the other hand, the violet laser beam having the center wavelength of 405 nm has a higher transmission component because the excitation light emission efficiency of the phosphor contained in the wavelength conversion members 57A and 57B is lower than that of the blue laser. As a result, in the violet laser light, the long-wavelength fluorescence from the wavelength conversion members 57A and 57B has a lower intensity than in the case of the blue laser, and illumination light having a narrow band wavelength is mainly emitted from the wavelength conversion members 57A and 57B. Is done. Violet laser light having a central wavelength of 405 nm is narrow-band light, and an observation image in which capillaries and fine structure patterns on the surface of a living tissue are emphasized can be obtained.

  Therefore, by mixing white light and narrow-band light at an appropriate light amount ratio and irradiating them simultaneously, it is possible to confirm the capillaries and fine structure patterns on the tissue surface layer with improved visibility along with the surroundings of the affected area. For such narrow-band light observation, narrow-band light with a center wavelength of 360 nm to 530 nm, preferably narrow-band light with a center wavelength of 380 to 450 nm can be used.

  The light source controller 59 individually drives the laser light sources LD1-A, LD1-B, LD2-A, and LD2-B, and the light quantity ratio between the white illumination light by the blue laser light and the narrow-band light by the violet laser. Can be arbitrarily set and emitted from each of the illumination windows 43A and 43B.

  By using the light source device 19A having the above-described configuration, the dimming control in S21, S22, S25, and S26 shown in FIG. 7 and the dimming control in S32 shown in FIG. It can be replaced by a control that changes the ratio. That is, in the halation generated in the observation image, the light component mainly generated by the white illumination light is conspicuous, and the light component generated by the narrow band light is not conspicuous compared with the white illumination light. Therefore, instead of reducing the amount of light emitted from the illumination window, the white illumination light that greatly contributes to the occurrence of halation is selectively dimmed and the amount of light that is insufficient due to the dimming control is controlled to increase the narrowband light. Thus, it is possible to perform the light amount ratio control to be supplemented.

  Such light quantity ratio control also has the effect of reducing halation, and the halation minimization light source control and optimized image generation processing can be performed as described above. Further, by increasing the light intensity ratio of the narrow-band light, it is possible to obtain an image in which capillary defects and fine structure patterns on the surface of the living tissue are emphasized. As a display image or a composite image on the display unit 15, Information useful for endoscopic diagnosis can be provided.

  As described above, the present invention is not limited to the above-described embodiments, and those skilled in the art can make changes and applications based on combinations of the configurations of the embodiments, descriptions in the specification, and well-known techniques. This is also the scope of the present invention, and is included in the scope for which protection is sought.

  For example, the laser light source may be a light source that extracts illumination light having an arbitrary wavelength by combining a light source using a light emitting diode, a xenon lamp that is a white light source, and a color filter.

As described above, the following items are disclosed in this specification.
(1) An endoscope apparatus in which an observation window and a pair of illumination windows are arranged at the front end of an endoscope insertion portion to be inserted into a subject,
The pair of illumination windows comprises a first illumination window disposed on one side of the observation window, and a second illumination window disposed on the other side,
A first light source for supplying illumination light to the first illumination window;
A second light source for supplying illumination light to the second illumination window;
An imaging device that images the subject through the observation window and outputs a captured image signal of the subject; and a halation detection unit that detects a halation occurrence region from luminance information of the captured image signal;
Control means for individually controlling the amount of light emitted from the first light source and the second light source according to each target light amount value set for each of the first light source and the second light source;
With
The first picked-up image with respect to the first picked-up image taken by dimming the first light source and the second picked-up image picked up by dimming the second light source. When the halation occurrence area is larger than the halation occurrence area of the second captured image, the target light amount value set for the first light source is decreased, and when the halation occurrence area is less, the target set for the second light source An endoscope apparatus that performs light amount control to reduce a light amount value.
According to this endoscope apparatus, by selectively reducing the target light amount value of the light source that mainly generates halation, the occurrence of halation can be suppressed while maintaining the quality of the observation image. An image suitable for mirror diagnosis can be obtained.

(2) The endoscope apparatus according to (1),
The halation occurrence region of the third captured image obtained by photographing the first light source and the second light source with the emitted light quantity corresponding to the target light quantity value subjected to the decrease control is determined in advance. An endoscope apparatus that repeats the light amount control until a predetermined area or less is reached.
According to this endoscope apparatus, the halation occurrence region can be minimized by repeating the reduction control of the target light amount value until the halation region is equal to or smaller than a predetermined area.

(3) The endoscope apparatus according to (1) or (2),
An endoscope apparatus in which the halation detection means detects a pixel having a maximum luminance value of a captured image obtained by quantizing the captured image signal as the halation occurrence region.
According to this endoscope apparatus, the halation occurrence region can be easily obtained by extracting the pixel having the maximum luminance value.

(4) The endoscope apparatus according to any one of (1) to (3),
A light amount change switch connected to the control means for changing the emitted light amount of the first light source and the second light source;
An endoscope apparatus in which the control means determines a decrease amount of the target light amount value according to an input operation from the light amount change switch.
According to this endoscope apparatus, it is possible to quickly set the target light amount reduction amount suitable for the observation image by the light amount change switch.

(5) The endoscope apparatus according to any one of (1) to (4),
A still image shooting button connected to the control means for inputting a still image shooting timing;
An endoscope apparatus in which the control means performs the light amount control when the still image shooting button is pressed.
According to this endoscope apparatus, by performing light amount control at the time of still image shooting, it is possible to more reliably suppress halation, particularly for still images that do not like the occurrence of halation.

(6) The endoscope apparatus according to any one of (1) to (5),
The control means controls the increase / decrease of the respective target light amount values for the first light source and the second light source so that the sum of the emitted light amounts of the first light source and the second light source is constant. Endoscopic device.
According to this endoscope apparatus, it is possible to prevent the observation image from becoming dark by making up for the light amount decrease of one light source with the other light source.

(7) The endoscope apparatus according to any one of (1) to (6),
Any one of a third captured image obtained by controlling the first light source and the second light source to an emitted light amount corresponding to the target light amount value, and the first light source and the second light source, respectively. Storage means for storing a fourth captured image that is captured by being dimmed from an emitted light amount corresponding to the target light amount value;
A first image area that is an area excluding the halation occurrence area of the third captured image, and a second image area that is an area including the halation occurrence area of the fourth captured image are defined as mutual image positions. Image combining means for combining the images,
An endoscopic apparatus comprising:
According to this endoscope apparatus, by combining the halation occurrence area in the captured image with the luminance information of the captured image captured while suppressing the halation, the entire synthesized image is combined with the image in which the halation is suppressed. Become.

(8) The endoscope apparatus according to (7),
The image synthesizing means;
An endoscope apparatus in which the first image area and the second image area are respectively defined in block units obtained by dividing the captured image into a plurality of areas.
According to this endoscope apparatus, since image composition is performed in units of blocks, arithmetic processing is simplified.

(9) The endoscope apparatus according to any one of (1) to (8),
The first light source and the second light source include a white light source for generating white illumination light, and a narrow band light source for generating narrow band light having a narrower wavelength band than the white illumination light. Each has
An endoscope for performing light amount control for reducing the target light amount value by changing the light amount emitted from the white light source to a low light amount ratio with respect to the light amount emitted from the narrow-band light source. apparatus.
According to this endoscope apparatus, it is possible to suppress the occurrence of halation by setting the emitted light amount of the white light source to a light amount ratio lower than the emitted light amount of the narrow-band light source.

(10) The endoscope apparatus according to (9),
An endoscope apparatus in which the narrow-band light source is a semiconductor light source having a central wavelength of 360 nm to 530 nm.
According to this endoscope apparatus, it is possible to obtain an observation image in which a capillary defect or a fine structure pattern on the surface of a biological tissue is emphasized.

(11) The endoscope apparatus according to (9) or (10),
Inside the illumination window, a wavelength conversion member including a phosphor that emits and emits light by light emitted from the light source for white light is disposed,
An endoscope apparatus in which white light is generated by combining light emitted from the light source for white light and light emitted from the phosphor.
According to this endoscope apparatus, high-intensity white light having a broad spectrum can be generated by the fluorescence generated from the wavelength conversion member, and the color rendering properties of the observation image can be improved.

DESCRIPTION OF SYMBOLS 11 Endoscope 13 Control apparatus 15 Display part 17 Input part 19 Light source device 21 Processor 25 Insertion part 30 Still image photography button 39 Front-end | tip part (endoscope front-end | tip part)
41 Observation window 43A Illumination window (first illumination window)
43B Lighting window (second lighting window)
45 Imaging element 53 Imaging signal processing unit 55A, 55B Optical fiber 57A, 57B Wavelength conversion member 59 Light source control unit 61 Foot switch 69 Endoscope control unit (Halation detection unit, control unit)
71 Memory (storage means)
73 Image processing unit 81 Observation image 83, 83A, 83B Halation 87 First light source unit 89 Second light source unit 91 Combiner 100 Endoscope device LD1 Laser light source (first light source)
LD2 Laser light source (second light source)
LD1-A, LD1-B, LD2-A, LD2-B Laser light sources H1, H2 Luminance information

Claims (11)

An endoscope apparatus in which an observation window and a pair of illumination windows are arranged across the observation window at the tip of an endoscope insertion portion to be inserted into a subject,
The pair of illumination windows comprises a first illumination window disposed on one side of the observation window, and a second illumination window disposed on the other side,
A first light source for supplying illumination light to the first illumination window;
A second light source for supplying illumination light to the second illumination window;
An imaging device that images the subject through the observation window and outputs a captured image signal of the subject; and a halation detection unit that detects a halation occurrence region from luminance information of the captured image signal;
Control means for individually controlling the amount of light emitted from the first light source and the second light source according to each target light amount value set for each of the first light source and the second light source;
With
The first picked-up image with respect to the first picked-up image taken by dimming the first light source and the second picked-up image picked up by dimming the second light source. When the halation occurrence area is larger than the halation occurrence area of the second captured image, the target light amount value set for the first light source is decreased, and when the halation occurrence area is less, the target set for the second light source An endoscope apparatus that performs light amount control to reduce a light amount value. The endoscope apparatus according to claim 1,
The halation occurrence region of the third captured image obtained by photographing the first light source and the second light source with the emitted light quantity corresponding to the target light quantity value subjected to the decrease control is determined in advance. An endoscope apparatus that repeats the light amount control until a predetermined area or less is reached. The endoscope apparatus according to claim 1 or 2,
An endoscope apparatus in which the halation detection means detects a pixel having a maximum luminance value of a captured image obtained by quantizing the captured image signal as the halation occurrence region. The endoscope apparatus according to any one of claims 1 to 3,
A light amount change switch connected to the control means for changing the emitted light amount of the first light source and the second light source;
An endoscope apparatus in which the control means determines a decrease amount of the target light amount value according to an input operation from the light amount change switch. The endoscope apparatus according to any one of claims 1 to 4,
A still image shooting button connected to the control means for inputting a still image shooting timing;
An endoscope apparatus in which the control means performs the light amount control when the still image shooting button is pressed. The endoscope apparatus according to any one of claims 1 to 5,
The control means controls the increase / decrease of the respective target light amount values for the first light source and the second light source so that the sum of the emitted light amounts of the first light source and the second light source is constant. Endoscopic device. The endoscope apparatus according to any one of claims 1 to 6,
Any one of a third captured image obtained by controlling the first light source and the second light source to an emitted light amount corresponding to the target light amount value, and the first light source and the second light source, respectively. Storage means for storing a fourth captured image that is captured by being dimmed from an emitted light amount corresponding to the target light amount value;
A first image area that is an area excluding the halation occurrence area of the third captured image, and a second image area that is an area including the halation occurrence area of the fourth captured image are defined as mutual image positions. Image combining means for combining the images,
An endoscopic apparatus comprising: The endoscope apparatus according to claim 7,
The image synthesizing means
An endoscope apparatus in which the first image area and the second image area are respectively defined in block units obtained by dividing the captured image into a plurality of areas. The endoscope apparatus according to any one of claims 1 to 8,
The first light source and the second light source include a white light source for generating white illumination light, and a narrow band light source for generating narrow band light having a narrower wavelength band than the white illumination light. Each has
An endoscope for performing light amount control for reducing the target light amount value by changing the light amount emitted from the white light source to a low light amount ratio with respect to the light amount emitted from the narrow-band light source. apparatus. The endoscope apparatus according to claim 9, wherein
An endoscope apparatus in which the narrow-band light source is a semiconductor light source having a central wavelength of 360 nm to 530 nm. The endoscope apparatus according to claim 9 or 10, wherein
Inside the illumination window, a wavelength conversion member including a phosphor that emits and emits light by light emitted from the light source for white light is disposed,
An endoscope apparatus in which white light is generated by combining light emitted from the light source for white light and light emitted from the phosphor.