JP6276985B2 - Endoscope apparatus and endoscope system - Google Patents

Description

  The present invention relates to an endoscope apparatus and an endoscope system that use special light.

  An endoscope apparatus that performs laser treatment using near-infrared laser light is known. The endoscope apparatus includes an endoscope scope that is inserted into a human body and captures an image in the body, and an endoscope processor that receives an image from the endoscope scope and performs image processing. The endoscope scope includes an image sensor at the tip. A broadband laser cut filter that reduces near-infrared laser light is attached to the imaging surface of the imaging device. Thereby, it is possible to prevent the charge from being excessively accumulated in the pixel due to the reflected light by the near-infrared laser beam, and to obtain a normal and always image of the subject (Patent Document 1).

JP 2001-314367 A

  However, special light having a wavelength included in the visible light band may be used for laser treatment. When such a filter for reducing special light is attached to the imaging device, special light can be reduced, but light in the visible light band is also reduced, and an image of the subject cannot be obtained normally and constantly.

  The present invention has been made in view of these problems, and obtains an endoscope apparatus and an endoscope system capable of obtaining an image of a subject using special light having a wavelength included in the visible light band. For the purpose.

  An endoscope apparatus according to a first invention of the present application processes a pixel data, an imaging element having a plurality of pixels that capture a subject image and output pixel data, and a filter attached to each of the plurality of pixels. And a processing unit for creating image data. The filter has a filter that mainly transmits light having a predetermined wavelength and a filter that mainly transmits light having a wavelength different from the predetermined wavelength. When the image sensor picks up an image mainly using light having a wavelength of, the processing unit does not use pixel data output by a pixel to which a filter that mainly transmits light having a predetermined wavelength is attached. Image data is created using only pixel data output from a pixel to which a filter that mainly transmits light having a wavelength different from the wavelength is attached.

  The image sensor can change the exposure period for accumulating charges in the pixels, and when the image sensor mainly captures light having a predetermined wavelength, the exposure period is longer than when the image is captured using normal light. It is preferable to shorten it. Charges accumulated in a pixel to which a filter that mainly transmits light having a predetermined wavelength is attached do not adversely affect other charges.

  The light source further includes a normal light source that emits normal light, and the normal light source increases the amount of normal light when the image pickup device mainly picks up light having a predetermined wavelength than when picking up the image using only normal light. It is preferable. Imaging can be performed with a sufficient amount of light.

  When the imaging device captures an image using normal light, the processing unit outputs pixel data output from a pixel to which a filter that mainly transmits light having a predetermined wavelength is attached, and light having a wavelength different from the predetermined wavelength. It is preferable to create image data using pixel data output from a pixel to which a filter that mainly transmits light is attached. It becomes possible to image using only ordinary light.

  The light having a predetermined wavelength is special light used for treating the observation object. When the observation object is treated using special light, the processing unit has a filter that mainly transmits the special light. Create image data using only the pixel data output from the pixel to which a filter that mainly transmits light having a wavelength different from the wavelength of the special light is used, without using the pixel data output by the attached pixel. It is preferable to do. Even when special light is emitted, a subject image can be obtained.

  The wavelength of the special light is preferably included in the wavelength of normal light.

  An endoscope system according to a second invention of the present application includes the endoscope apparatus and a special light source that emits light having a predetermined wavelength.

  According to the present invention, an endoscope apparatus and an endoscope system capable of obtaining an image of a subject using special light having a wavelength included in the visible light band are obtained.

It is the block diagram which showed the endoscope apparatus and endoscope system by this invention. It is a figure showing a pixel with which an image sensor is provided. It is the graph which showed the relationship between the wavelength of light, and the relative sensitivity of a pixel. It is the block diagram which showed the process by an endoscope apparatus. It is the flowchart which showed the laser treatment mode process.

  Hereinafter, an endoscope system 100 according to an embodiment of the present invention will be described.

FIG. 1 schematically shows an endoscope system 100.
The endoscope system 100 mainly includes an endoscope apparatus 101 and a special light source 102 that emits special light.

  The special light source 102 generates KTP laser light and irradiates the object to be observed. KTP laser light has a wavelength of 532 nm included in the visible light band and is used to treat the affected area.

  The endoscope apparatus 101 mainly includes an endoscope scope 110 that images an observation target and outputs image data, and an endoscope processor 130 that receives an image from the endoscope scope 110 and performs image processing. Prepare.

  The endoscope scope 110 mainly includes a CCD 111, an amplifier 112, an analog signal processing circuit 113, a video processing circuit 114, a CCD drive circuit 115, a scope system controller 116, and a light guide fiber 117.

  The CCD 111 has a plurality of pixels and a filter attached to each pixel. For example, the CCD 111 is inserted into a human body to image an observation target and output an analog signal. The configuration of the CCD 111 will be described later.

  The amplifier 112 receives an analog signal from the CCD 111 and amplifies it. The analog signal processing circuit 113 receives the amplified analog signal from the amplifier 112 and converts it into a digital signal.

  The video processing circuit 114 performs predetermined processing such as laser treatment mode processing on the digital signal. The laser treatment mode process will be described later.

  The CCD drive circuit 115 drives the CCD 111 so as to capture an image at a predetermined shutter speed, that is, an exposure period.

  The scope system controller 116 controls the analog signal processing circuit 113 and the CCD driving circuit 115.

  The light guide fiber 117 irradiates the observation object with normal light received from the endoscope processor 130. Normal light refers to white light or light that looks like sunlight to the human eye.

  The endoscope processor 130 includes a front-stage signal processing circuit 131, an image memory 132, a rear-stage signal processing circuit 133, a processor system controller 134, a light source power source 135, a normal light source 136, a condenser lens 137, and a light source aperture. 138 and a motor 139 are mainly provided.

  The processor system controller 134 controls the operation of the endoscope processor 130 and is connected to the scope system controller 116 to transmit a predetermined command to the endoscope scope 110.

  The pre-stage signal processing circuit 131 receives image data from the video processing circuit 114, performs predetermined image processing, and outputs a processed image. The predetermined image processing is, for example, gain adjustment processing, white balance adjustment processing, contour enhancement processing, and pixel enhancement processing. The gain adjustment process is a process of adjusting the gain of the image data to adjust the signal level of the image data to a level suitable for observation. The white balance adjustment process is a process for adjusting the color balance by adjusting the white balance of the image data. The contour emphasizing process is a process for emphasizing a subject image, for example, the contour of the affected part to clarify the range of the affected part, thereby making it easier to observe and find the affected part. The pixel enhancement process is a process that emphasizes only the reflected light of a specific wavelength, thereby making it easy to see the affected part that returns the reflected light of a specific wavelength.

  The image memory 132 stores processed images.

  The post-stage signal processing circuit 133 reads the processed image from the image memory 132, changes the format to a format that can be displayed by the monitor 103, and creates a display image.

  The monitor 103 receives and displays the display image.

  The light source power supply 135 supplies power to the normal light source 136 in accordance with a signal from the processor system controller 134. The normal light source 136 receives power from the light source power source 135 and emits normal light. The brightness of the normal light changes according to the power supplied from the light source power supply 135.

  Normal light enters the light guide fiber 117 via the condenser lens 137 and the light source aperture 138. The light source aperture 138 is composed of a rotary shutter, and adjusts the amount of normal light and the light emission timing. The opening degree and timing of the light source aperture 138 are controlled by a motor 139 connected to the processor system controller 134.

  Next, the CCD 111 will be described with reference to FIG. FIG. 2 is a diagram illustrating a part of the imaging surface of the CCD 111.

  The CCD 111 has a plurality of pixels and a filter attached to each pixel. Each of the plurality of pixels outputs pixel data. The filter includes a red filter R that mainly transmits light having a red wavelength, a blue filter B that mainly transmits light having a blue wavelength, and a green filter G that mainly transmits light having a green wavelength. Is provided. The red filter R, the blue filter B, and the green filter G are arranged in a Bayer array and attached to the pixel. As a result, the pixel to which the red filter R is attached has high sensitivity to red, and the luminance relating to red is mainly output as pixel data. The pixel to which the blue filter B is attached has high sensitivity to blue. The luminance mainly related to blue is output as pixel data, and the pixel to which the green filter G is attached has high sensitivity to green, and mainly outputs the luminance related to green as pixel data.

  Next, the sensitivity of a pixel to which the red filter R, the blue filter B, and the green filter G are attached will be described with reference to FIG.

  FIG. 3 is a diagram showing the relationship between the wavelength of light and the relative sensitivity of pixels. In the pixel to which the red filter R is attached, the relative sensitivity increases rapidly from the vicinity of the wavelength of 560 nm, and the relative sensitivity takes the maximum value in the vicinity of 590 nm. And relative sensitivity falls as a wavelength becomes long. In the pixel to which the blue filter B is attached, the relative sensitivity increases from around the wavelength of 400 nm, and the relative sensitivity takes the maximum value around 470 nm. Then, after the relative sensitivity rapidly decreases to the wavelength of 510 nm, the relative sensitivity gradually decreases as the wavelength becomes longer. In the pixel to which the green filter G is attached, the relative sensitivity increases from around the wavelength of 460 nm, and the relative sensitivity takes the maximum value from around 510 nm to around 550 nm. And after a relative sensitivity falls rapidly to wavelength 610nm, a relative sensitivity falls gradually as a wavelength becomes long.

  Here, the KTP laser light has a wavelength of 532 nm as described above. A pixel to which the green filter G is attached has a relative sensitivity of about 0.7 with respect to light having a wavelength of 532 nm, but a pixel to which the red filter R is attached has a relative sensitivity of about 0.3 and a blue filter B is attached. The relative sensitivity of the obtained pixels is only about 0.2. That is, the laser beam having a wavelength of 532 nm is mainly transmitted by the green filter G, but is not substantially transmitted by the red filter R and the blue filter B. Since KTP laser light is used to treat an affected area, the amount of light is generally large. Therefore, the accumulated charge is saturated in the pixel that has received the KTP laser beam. When the charge is saturated, the image causes so-called halation, and a normal image cannot be obtained. That is, since the pixel to which the green filter G is attached has a relative sensitivity of about 0.7, the charge is saturated by the KTP laser light. However, since the pixel to which the red filter R and the blue filter B are attached has a relative sensitivity of about 0.2 to about 0.3, the possibility that the charge is saturated by the KTP laser light is low. Therefore, if image data is created using pixel data output from the pixels to which the red filter R and the blue filter B are attached without using the pixel data output from the pixels to which the green filter G is attached, there is no halation. An image can be obtained.

  Next, the configuration of the video processing circuit 114 and its peripheral circuits will be described with reference to FIG. When the user operates a switch provided on the front panel (not shown) and selects the normal light observation mode process, the video processing circuit 114 executes the normal light observation mode process, and when the laser treatment mode process is selected, Laser treatment mode processing is executed.

First, the normal light observation mode process will be described. The normal light observation mode process is a process in which normal light is used for observation, and an image similar to that obtained when the observation object is viewed in sunlight can be obtained. In the normal light observation mode process, the normal light source 136 emits normal light, and the special light source 102 does not emit KTP laser light. The CCD 111 images the observation object using only normal light, and the pixels included in the CCD 111 output pixel data. The video processing circuit 114 calculates luminance information Ys, red information Rs, green information Gs, and blue information Bs using all pixel data based on the following formula. Here, Rin is pixel data output from a pixel to which a red filter R is attached, Gin is pixel data output from a pixel to which a green filter G is attached, and Bin is attached to a blue filter B. This is pixel data output from the selected pixel. Ka1, Kb1, Kc1, Ka2, Kb2, Kc2, Ka3, Kb3, and Kc3 are arbitrary coefficients.
Ys = (0.3 · Rin + 0.6 · Gin + 0.1 · Bin)
Rs = (Ka1 · Rin) + (Kb1 · Gin) + (Kc1 · Bin)
Gs = (Ka2 · Rin) + (Kb2 · Gin) + (Kc2 · Bin)
Bs = (Ka3 · Rin) + (Kb3 · Gin) + (Kc3 · Bin)

  Next, laser treatment mode processing will be described. The laser treatment mode process is a process for obtaining an image of an observation object during a period in which an affected area is treated using a KTP laser.

  In the laser treatment mode process, the normal light source 136 emits normal light with a light quantity larger than that in the normal light observation mode process, and the special light source 102 generates KTP laser light and irradiates the affected part.

  The CCD 111 captures an image with a shutter speed that is shorter than when the normal light observation mode process is executed, that is, with a shorter exposure period. When the KTP laser beam is irradiated, as described above, the charge of the pixel to which the green filter G is attached tends to be saturated. The saturated charge has an adverse effect such as noise on the charge accumulated in the adjacent pixels. As a result, smear or the like occurs in the image. Therefore, imaging is performed with a shorter exposure period than when the normal light observation mode process is executed. This reduces the amount of charge accumulated in the pixel to which the green filter G is attached, thereby reducing the adverse effect on the charge accumulated in the adjacent pixel.

  On the other hand, the normal light source 136 emits normal light with a larger amount of light than when executing the normal light observation mode process. Since the CCD 111 captures an image with a shutter speed shorter than when the normal light observation mode process is executed, if the normal light is emitted with the same light amount as when the normal light observation mode process is executed, the light amount is insufficient. there's a possibility that. Therefore, by emitting normal light with a larger amount of light than when executing the normal light observation mode processing, the pixel can accumulate charges using a sufficient amount of normal light.

Based on the following formula, the video processing circuit 114 uses the pixel data output from the pixel to which the red filter R is attached and the pixel data output from the pixel to which the blue filter B is attached, to obtain luminance information Yinf and red information. Rinf, green information Ginf, and blue information Binf are calculated. Here, since Rin, Gin, and Bin are the same as those described above, description thereof is omitted. Ka1, Kc1, Ka2, Kc2, Ka3, and Kc3 are arbitrary coefficients. By appropriately adjusting Ka1, Kc1, Ka2, Kc2, Ka3, and Kc3, the user can observe at least the contour of the subject. Further, since the luminance information Yinf, red information Rinf, green information Ginf, and blue information Binf are calculated without using the pixel data Gin output by the pixel to which the green filter G is attached, the image is disturbed by the KTP laser light. Can be prevented. Furthermore, in order to calculate the luminance information Yinf, the red information Rinf, the green information Ginf, and the blue information Binf using only the pixel data Rin and Bin output by the pixel to which the red filter R and the blue filter B are attached, the KTP laser beam It is possible to obtain an appropriate image by eliminating the influence of.
Yinf = (0.3Rin + 0.1Bin)
Rinf = (Ka1 · Rin) + (Kc1 · Bin)
Ginf = (Ka2 · Rin) + (Kc2 · Bin)
Binf = (Ka3 · Rin) + (Kc3 · Bin)

  The luminance information Yinf, red information Rinf, green information Ginf, and blue information Binf calculated by the above processing are transmitted to the pre-stage signal processing circuit 131.

  Next, the laser treatment mode process will be described with reference to FIG.

  In the first step S51, the video processing circuit 114 receives only the pixel data Rin and Bin and discards the pixel data Gin.

  In the next step S52, the CCD drive circuit 115 sets the shutter speed of the CCD 111 to the fastest value, that is, sets the exposure period to the shortest value.

  In the next step S53, the power supplied from the light source power supply 135 to the normal light source 136 is adjusted, and the normal light source 136 emits normal light with the maximum light amount according to the supplied power.

  In the next step S54, the CCD 111 takes an image and outputs pixel data.

  In the next step S55, the video processing circuit 114 calculates the luminance information Yinf, the red information Rinf, the green information Ginf, and the blue information Binf using the above-described mathematical expressions. Then, the process ends.

  According to the present embodiment, luminance information Yinf, red information Rinf, green information Ginf, and blue information Binf are calculated using only pixel data Rin and Bin output by pixels to which the red filter R and the blue filter B are attached. Therefore, an appropriate image can be obtained without the image being disturbed by the KTP laser light.

  Note that the numbers multiplied by Rin, Gin, and Bin when calculating the luminance information Yinf are not limited to those described above.

  The coefficients Ka1, Kc1, Ka2, Kc2, Ka3, and Kc3 used in the laser treatment mode process are different from the coefficients Ka1, Kc1, Ka2, Kc2, Ka3, and Kc3 used in the normal light observation mode process. May be.

  Note that the number multiplied by Rin, Gin, and Bin when calculating the luminance information Yinf in the laser treatment mode process may be different from the number multiplied in the normal light observation mode process.

  Note that only the luminance information Yinf may be calculated in the laser treatment mode process. A monochrome image can be obtained.

  In the laser treatment mode process, the red information Rinf, the green information Ginf, and the blue information Binf may not be calculated and may be fixed values.

  Although the filter has been described as a primary color filter, it may be a complementary color filter.

  Although the video processing circuit 114 has been described as executing the normal light observation mode process and the laser treatment mode process, other circuits included in the endoscope scope 110 or the endoscope processor 130 may execute these processes. .

  The imaging device is not limited to the CCD 111, and may be a solid-state imaging device such as a CMOS.

DESCRIPTION OF SYMBOLS 100 Endoscope system 101 Endoscope apparatus 102 Laser apparatus for treatment (special light source)
110 Endoscope scope 111 CCD
112 Amplifier 113 Analog signal processing circuit 114 Video processing circuit 115 CCD drive circuit 116 Scope system controller 117 Light guide fiber 130 Endoscope processor 131 Pre-stage signal processing circuit 132 Image memory 133 Post-stage signal processing circuit 134 Processor system controller 135 Light source power source 136 Normal Light source 137 Condensing lens 139 Motor B Blue filter G Green filter R Red filter

Claims (7)

An imaging device having a plurality of pixels that capture a subject image and output pixel data, and three or more types of filters having different wavelength ranges of transmitted light ;
A processing unit that processes the pixel data to create image data;
The filter includes a filter that is light used for treating an observation object and transmits more special light whose wavelength is included in the visible light region compared to other filters,
When the imaging device captures an image while treating the observation object using the special light, the processing unit is a pixel to which a remaining filter other than a filter that transmits the special light more than other filters is attached. There using the pixel data to be output, an endoscope apparatus for creating the image data. The imaging device can change an exposure period for accumulating charges in the pixels, and when the imaging device captures an image while treating the observation object using the special light, the imaging device captures an image using only normal light. The endoscope apparatus according to claim 1, wherein the exposure period is shorter than the case. The light source further includes a normal light source that irradiates normal light, and the normal light source emits normal light when the imaging device captures an image while treating the observation object using the special light, rather than using normal light alone. The endoscope apparatus according to claim 2, which increases the amount of light. When the imaging device uses only normal light to capture an image, the processing unit outputs pixel data output from a pixel to which a filter that transmits the special light more than other filters is attached, and the remaining remaining The endoscope apparatus according to any one of claims 1 to 3, wherein the image data is created using pixel data output from a pixel to which a filter is attached. The filter comprises a red filter that mainly transmits light having a red wavelength, a green filter that mainly transmits light having a green wavelength, and a blue filter that mainly transmits light having a blue wavelength,
When the imaging element captures an image while treating the observation object using the special light, the processing unit transmits the special light more than the red filter and the blue filter, except for the green filter. using the pixel data of pixels where the blue filter and the red color filter is attached to the output, the endoscope apparatus according to any one of claims 1 to 4 to create the image data. The endoscope apparatus according to claim 1 , wherein the special light is KTP laser light . The endoscope system including an endoscope apparatus according, a special light source for emitting the special light to any one of claims 1 to 6.

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