JP5922955B2 - Electronic endoscope system - Google Patents

Description

  The present invention is an electronic endoscope system that displays an endoscopic image output from an electronic endoscope on a monitor, and in particular, an electronic endoscopic system that simultaneously displays a plurality of different endoscopic images on a monitor. About.

  Conventionally, examinations using an electronic endoscope system have been widely used in the medical field. In an electronic endoscope system, illumination light (hereinafter referred to as “normal light” or “white light”) from a light source device having a white light source such as a xenon lamp is guided into a body cavity using a light guide or the like. Then, an electronic endoscope having an imaging means for imaging a subject with the return light is used, and an endoscope image (on the observation monitor) is processed by processing an imaging signal from the electronic endoscope by an endoscope processor. Hereinafter, “normal image”) is displayed. In addition, the image pickup signal from the electronic endoscope is fed back to the light source device, and the brightness of the normal image displayed on the observation monitor is controlled to be constant by adjusting the amount of light with, for example, a diaphragm mechanism. (For example, patent document 1).

  In recent years, in order to facilitate the detection of lesions, a specific narrow band light (hereinafter referred to as “special light”) is irradiated into a body cavity, and the return light from this is imaged (hereinafter referred to in this way). An electronic endoscope system that observes the obtained image as a “special image”) is also used. According to observation with special light, it is possible to highlight and display an image in which blood vessels in the submucosal layer are emphasized and surface tissues of organs such as stomach walls and intestines. In this type of electronic endoscope system, a normal image by normal light and a special image by special light are simultaneously displayed on one screen, and a diagnosis can be made while comparing the images. (For example, Patent Document 2).

JP 2008-279077 A JP 2010-184047 A

  The electronic endoscope system described in Patent Document 2 has a light source for normal light and a light source for special light, and these are alternately switched in units of the storage period of the imaging means (that is, every frame). By capturing an image, a normal image and a special image are acquired and displayed almost simultaneously. However, since the brightness (luminance) of a special image and the brightness of a normal image are generally different, if the image is acquired while switching the light source every frame (that is, every 1/30 seconds), every frame Therefore, it becomes impossible to adjust the light amounts of the normal light and the special light by feeding back the image pickup signal to the light source device as in the configuration described in Patent Document 1. Therefore, there is a problem that a normal image and a special image with different luminance levels are displayed.

  In order to solve such a problem, for example, it is conceivable to change the brightness of the normal image and the special image by image processing or the like. However, the brightness of each image desired by the surgeon changes from time to time depending on the object to be imaged, the angle, etc., and it is extremely complicated to frequently perform such brightness adjustment during the procedure. A configuration that can be adjusted by using this method has been desired.

  The present invention has been made in view of the above circumstances, and an electronic endoscope capable of automatically adjusting brightness so that each of a plurality of endoscopic images displayed simultaneously has a desired brightness. An object is to provide a mirror system.

  An electronic endoscope system according to an aspect of the present invention that solves the above problems includes a light source that emits illumination light, a light amount adjusting unit that adjusts the light amount of the illumination light, and an object that is irradiated with the illumination light. An electronic endoscope that captures an image and outputs an image signal; and a first endoscope image that receives the image signal, generates a first endoscope image having a luminance corresponding to the value of the first luminance setting parameter, and outputs the first endoscope image as a first video signal Image processing means; second image processing means for receiving an image signal, generating a second endoscopic image having a luminance according to a value of a second luminance setting parameter, and outputting the second endoscope image as a second video signal; First luminance setting means for setting the target luminance of the mirror image as the first luminance, second luminance setting means for setting the target luminance of the second endoscope image as the second luminance, the first video signal and the second video A display hand that receives a signal and displays a first endoscope image and a second endoscope image And a luminance adjusting unit that adjusts the value of the first luminance setting parameter and the value of the second luminance setting parameter, and the light amount adjusting unit adjusts the light amount so that the luminance of the first endoscopic image becomes the first luminance. The brightness adjustment means is based on the light quantity set by the light quantity adjustment means and the ratio between the first brightness and the second brightness so that the brightness of the second endoscopic image becomes the second brightness. The value of the second brightness setting parameter is changed, and the first image processing means and the second image processing means receive image signals alternately every frame.

  According to such a configuration, the brightness of the first endoscopic image is adjusted to the first brightness, and the brightness of the second endoscopic image is set to the second brightness by changing the value of the second brightness setting parameter. Adjusted to That is, brightness adjustment is automatically performed so that each of a plurality of endoscopic images displayed at the same time has a desired brightness.

  The illumination light includes white light and a predetermined narrow band light, and further includes an illumination light switching unit that switches between the white light and the predetermined narrow band light. It can be configured to switch between white light and predetermined narrow band light for each frame. In this case, the first image processing means receives the image signal when the white light is irradiated, and the second image processing means receives the image signal when the predetermined narrow band light is irradiated. Is preferred. According to such a configuration, a normal image using white light and a special image using special light can be displayed simultaneously on one screen, and diagnosis can be performed while comparing the images.

  The first luminance setting means is configured to set the optimum luminance for the white light as the first luminance, and the second luminance setting means is set to set the optimum luminance for the predetermined narrowband light as the second luminance. be able to. According to such a configuration, it is possible to obtain a normal image and a special image that are adjusted to an optimum luminance according to the illumination light.

  The light amount adjusting means is a diaphragm mechanism arranged in the optical path of the illumination light, and each of the first luminance setting parameter and the second luminance setting parameter includes an aperture value of the diaphragm mechanism, an electronic shutter speed of the image sensor, and The amplification factor of the image signal can be included.

In addition, when changing the value of the second brightness setting parameter, the brightness adjusting means changes the aperture value with the first priority and increases the electronic shutter speed to the second when the brightness of the second endoscopic image is increased . In the case where the amplification factor is changed with the third priority and the brightness of the second endoscope image is lowered , the electronic shutter speed is changed with the first priority, and the amplification factor is changed to the second priority. It is preferable to change the priority order so that the aperture value is not changed. According to such a configuration, noise in the second endoscopic image does not increase.

  In addition, when the aperture value of the second brightness setting parameter is changed, the brightness adjusting unit preferably changes the electronic shutter speed or the amplification factor of the first brightness setting parameter according to the changed aperture value.

  Further, it is preferable that the brightness adjusting unit changes the electronic shutter speed with priority over the amplification factor when changing the first brightness setting parameter.

  Further, the first luminance and the second luminance may be the same. According to such a configuration, it is possible to obtain a first endoscope image and a second endoscope image with uniform brightness.

  The first brightness setting means sets the first brightness according to the input to the input means, and the second brightness setting means according to the input to the input means. It is preferable to set the second luminance.

The light intensity adjusting means includes a first dimming parameter that defines the dimming condition of the first endoscope image and a second dimming parameter that defines the dimming condition of the second endoscope image. The light amount is adjusted so that the luminance of the first endoscopic image becomes the first luminance under the light adjustment condition of the one light adjustment parameter, and the luminance adjustment unit has the light amount and the first light adjustment set by the light amount adjustment unit. The brightness of the second endoscope image is obtained under the parameter dimming condition, and the brightness of the second endoscope image is obtained under the light quantity set by the light quantity adjusting means and the dimming condition of the second dimming parameter. , Instead of the ratio between the first luminance and the second luminance , the luminance of the second endoscope image obtained under the light amount set by the light amount adjusting means and the dimming condition of the first dimming parameter, and the light amount It is obtained under the light amount set by the adjusting means and the dimming condition of the second dimming parameter. Was based on the ratio between the luminance of the second endoscope image can be configured to so that to change the value of the second brightness setting parameters. According to such a configuration, it is also possible to apply different light control methods for the first endoscope image and the second endoscope image.

  From another viewpoint, an electronic endoscope system according to an aspect of the present invention includes a light source that emits illumination light, a light amount adjustment unit that adjusts the light amount of the illumination light, and a subject irradiated with the illumination light. An electronic endoscope that captures an image with an image sensor and outputs an image signal; receives the image signal; generates a first endoscope image having a luminance corresponding to the value of the first luminance setting parameter; and outputs the first endoscope image as a first video signal First image processing means; second image processing means for receiving an image signal, generating a second endoscopic image having a luminance corresponding to the value of the second luminance setting parameter, and outputting the second endoscope image as a second video signal; Display means for receiving the video signal and the second video signal and displaying the first endoscopic image and the second endoscopic image, and brightness for adjusting the value of the first brightness setting parameter and the value of the second brightness setting parameter Adjustment means, and the light quantity adjustment means controls the brightness of the first endoscopic image. The brightness adjustment means adjusts the second brightness setting parameter based on the light quantity set by the light quantity adjustment means so that the brightness of the second endoscopic image becomes a predetermined brightness. The value is changed, and the first image processing means and the second image processing means receive image signals alternately every frame.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic endoscope system which can perform brightness | luminance adjustment automatically so that each of the several endoscopic image displayed simultaneously may become desired brightness is provided.

1 is a block diagram illustrating a configuration of an electronic endoscope system according to a first embodiment of the present invention. It is a figure which shows the structure of the rotary filter turret mounted in the processor which the electronic endoscope system which concerns on the 1st Embodiment of this invention has. It is a figure which shows the example of a display screen of 1st image | video IM1 and 2nd image | video IM2 displayed on the monitor which the electronic endoscope system which concerns on the 1st Embodiment of this invention has. It is a flowchart of the endoscope image observation process performed with the electronic endoscope system which concerns on the 1st Embodiment of this invention. It is a flowchart of the endoscope image observation process performed with the electronic endoscope system which concerns on the 2nd Embodiment of this invention.

  Hereinafter, an electronic endoscope system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an electronic endoscope system 1 according to the first embodiment of the present invention. As shown in FIG. 1, the electronic endoscope system 1 is a medical imaging system, and includes an electronic scope 100, a processor 200, and a monitor 300. The proximal end of the electronic scope 100 is connected to the processor 200. The processor 200 integrally includes an image signal processing device that processes an image signal output from the electronic scope 100 to generate an image, and a light source device that illuminates a body cavity that does not reach natural light via the electronic scope 100. Device.

  As illustrated in FIG. 1, the processor 200 includes a system controller 202, a timing controller 204, and the like. The system controller 202 controls each element constituting the electronic endoscope system 1. The timing controller 204 outputs a clock pulse for adjusting the signal processing timing to each circuit in the electronic endoscope system 1.

  The lamp 208 radiates light in a wavelength range mainly extending from the visible light region to the invisible infrared region after being started by the lamp power igniter 206. As the lamp 208, a high-intensity lamp such as a xenon lamp, a halogen lamp, a mercury lamp, or a metal halide lamp is suitable. The illumination light emitted from the lamp 208 is incident on the rotary filter turret 212 while being condensed by the condenser lens 210.

  FIG. 2 is a diagram showing a configuration of the rotary filter turret 212. As shown in FIG. 2, the rotary filter turret 212 has two optical filters F <b> 1 and F <b> 2 that are arranged symmetrically with respect to the rotation axis AX of the rotary filter turret 212, one of which is an illumination. It is arranged in the optical path. The optical filter F1 is a filter that transmits light in the entire visible light region, and the illumination light that has passed through the optical filter F1 becomes white light (that is, normal light). The optical filter F2 is a narrowband optical filter having a transmission peak with a narrow half-value width in a wavelength range suitable for absorption of hemoglobin, for example. The illumination light that has passed through the optical filter F2 is narrowband light (that is, special light). ) In another embodiment, the optical filter F2 may be a narrow-band optical filter having a transmission peak with a narrow half-value width in another wavelength region (for example, a wavelength region corresponding to the gland duct structure of the stomach).

  The motor 214 (FIG. 1) is a step motor driven under the control of the driver 216, for example, and is mechanically coupled to the rotary filter turret 212 via a transmission mechanism such as an arm or a gear (not shown). The motor 214 rotates the rotary filter turret 212 by an angle corresponding to the applied voltage (pulse). That is, the rotary filter turret 212 rotates under the control of the driver 216, and the optical filter F1 or F2 is selectively inserted into the illumination optical path. In the vicinity of the outer peripheral edge of the rotary filter turret 212, a position detection hole H for detecting the home position is formed. The system controller 202 recognizes which optical filter is arranged in the illumination optical path based on the detection of the position detection hole H through the photo interrupter FI and the number of pulses applied to the motor 214.

  The surgeon can rotate the rotary filter turret 212 through a display mode setting operation on the front panel 218 or an operation of a display mode setting button 114 provided on a hand operation unit (not shown) of the electronic scope 100. Although details will be described later, in the electronic endoscope system 1 of the present embodiment, an endoscope image (normal image) observation using normal light (hereinafter referred to as “normal imaging mode”) is performed by an operator's operation. ), Observation of endoscopic images (special images) using special light (hereinafter referred to as “special imaging mode”), or observation of endoscopic images using both normal light and special light (hereinafter referred to as “simultaneous imaging mode”). (Referred to as “shooting mode”), and one of the optical filters F1 and F2 is arranged in the illumination optical path at a predetermined timing in accordance with the set display mode. In FIG. 1, the connection between the display mode setting button 114 and other blocks is omitted to simplify the drawing.

  Various forms of the configuration of the front panel 218 are assumed. As a specific configuration example of the front panel 218, a hardware key for each function mounted on the front surface of the processor 200, a touch panel GUI (Graphical User Interface), a combination of a hardware key and a GUI, and the like are assumed. .

  The illumination light that has passed through the optical filter F1 or F2 is limited to an appropriate light amount by the diaphragm 213. A motor 215 is mechanically connected to the diaphragm 213 via a transmission mechanism such as an arm or a gear (not shown). The motor 215 is a DC motor, for example, and is driven under the control of the driver 216. The aperture 213 changes its opening degree by driving the motor 215 in order to make the image displayed on the display screen of the monitor 300 appropriate brightness, and the opening amount of the illumination light emitted from the optical filter F1 or F2 is changed. Restrict according to The appropriate reference for the brightness of the image is changed according to the brightness adjustment operation performed by the operator on the front panel 218 or the hand operation unit of the electronic scope 100.

  The irradiation light that has passed through the diaphragm 213 enters an incident end of an LCB (Light Carrying Bundle) 102. Irradiation light incident on the incident end of the LCB 102 propagates through the LCB 102 by repeating total reflection. Irradiation light propagating through the LCB 102 is emitted from the emission end of the LCB 102 disposed at the tip of the electronic scope 100. The irradiation light emitted from the emission end of the LCB 102 irradiates the subject via the light distribution lens 104. The reflected light from the subject forms an optical image at each pixel on the light receiving surface of the solid-state image sensor 108 via the objective lens 106.

  The solid-state image sensor 108 is a single-plate color CMOS (Complementary Metal Oxide Semiconductor) image sensor in which various filters such as an IR (InfraRed) cut filter 108a and a Bayer array color filter 108b are arranged on the front surface of the light receiving surface. The optical image formed by the pixel is accumulated as a charge corresponding to the amount of light, and converted into an imaging signal corresponding to each of R, G, and B colors. The converted imaging signal is input to the endoscope side signal processing circuit 112 after signal amplification (analog gain) by the preamplifier 110. The solid-state image sensor 108 is not limited to a CMOS image sensor, but may be a CCD (Charge-Coupled Device) image sensor.

  The timing controller 204 supplies clock pulses to the endoscope side signal processing circuit 112 according to the timing control by the system controller 202. The endoscope side signal processing circuit 112 controls driving of the solid-state imaging device 108 at a timing synchronized with a frame rate of a video processed on the processor 200 side, according to a clock pulse supplied from the timing controller 204.

  The imaging signal input to the endoscope side signal processing circuit 112 is subjected to predetermined analog signal processing, AD conversion, signal amplification (digital gain), and input to the processor side signal processing circuit 220.

  The processor side signal processing circuit 220 includes an image processing circuit 222, a frame memory 224, and an image composition circuit 226. The image processing circuit 222 performs predetermined image processing such as gamma correction and contour enhancement on the digital image data output from the endoscope side signal processing circuit 112, and buffers the frame data in the frame memory 224. In the present embodiment, since it is necessary to output the normal image and the special image at the same time in the simultaneous shooting mode, the normal image and the special image are respectively stored in the frame memory 224 according to the illumination light at the time of imaging. Are configured to be stored in separate memory areas. The image processing circuit 222 sweeps out the buffered image data IS1 of the normal image and the image data IS2 of the special image from the frame memory 224 at a timing controlled by the timing controller 204, and outputs it to the image composition circuit 226. The image composition circuit 226 composes at least one of the normal image and the special image output from the image processing circuit 226 into one image in accordance with the display mode set by the operator. Then, the video signal is converted into a predetermined format video signal (for example, NTSC (National Television System Committee) format) and output to the monitor 300. As a result, the monitor 300 has a normal image (hereinafter referred to as “first video IM1”), a special image (hereinafter referred to as “second video IM2”), or both a normal image and a special image (that is, the first video IM1). Both the first video IM1 and the second video IM2) are displayed.

  FIG. 3 is a schematic diagram showing the first video IM1 and the second video IM2 displayed on the monitor 300 of the present embodiment. FIG. 3A shows a first video IM1 displayed on the monitor 300 in the normal shooting mode. FIG. 3B shows the second video IM2 displayed on the monitor 300 in the special shooting mode. FIG. 3C shows the first video IM1 and the second video IM2 displayed on the monitor 300 in the simultaneous shooting mode. As shown in FIG. 3, in the normal shooting mode or the special shooting mode, either the first video IM1 or the second video IM2 is displayed on the monitor 300. In the simultaneous shooting mode, the first video IM1 and the second video are displayed. IM2 is displayed side by side on the monitor 300, and diagnosis can be performed while observing these simultaneously. And in this embodiment, the brightness | luminance adjustment of the image | video according to each display mode is performed by the endoscopic image observation process mentioned later. Specifically, in the normal shooting mode and the special shooting mode, the system controller 202 controls the aperture 213 so that the first video IM1 or the second video IM2 displayed on the monitor 300 has appropriate brightness. In the simultaneous shooting mode, based on the aperture value of the aperture 213 (that is, the amount of white light) when the first image IM1 is displayed, and the brightness setting values of the first image IM1 and the second image IM2, A setting value (hereinafter referred to as “brightness setting parameter”) relating to the brightness of the first video IM1 and the second video IM2 is changed and automatically adjusted so that both have a predetermined brightness (details will be described later). . In the present embodiment, as the brightness setting parameters for determining the brightness of the first video IM1 and the second video IM2, the aperture value of the aperture 213, the electronic shutter speed of the solid-state image sensor 108, the amplification factor (analogue) of the preamplifier 110 Gain) and the amplification factor (digital gain) of the endoscope side signal processing circuit 112. The luminance setting parameter is stored in the memory 203 connected to the system controller 202, and is read out as necessary and set in each circuit, and is updated as appropriate. The transmittances of the optical filters F1 and F2 are measured in advance in the factory and recorded in the memory 203. In the present embodiment, the following description will be made assuming that the transmittance of the optical filter F2 is 50% of the transmittance of the optical filter F1.

(Endoscopic image observation processing according to the first embodiment)
FIG. 4 is a flowchart of endoscopic image observation processing according to the present embodiment. In the endoscopic image observation process, an endoscopic image (that is, at least one of the first video IM1 and the second video IM2) is displayed in a form corresponding to the display mode set by the operator. Execution of the endoscope image observation process is started when the electronic endoscope system 1 is activated. For convenience of explanation, the processing step is abbreviated as “S” in the explanation and drawings in this specification.

  When the endoscopic image observation process is started, the system controller 202 executes the process of S101.

  In step S <b> 101, the system controller 202 determines which of the normal shooting mode, the special shooting mode, and the simultaneous shooting mode is set by the operator operating the front panel 218 or the display mode setting button 114. If the normal shooting mode is set, the process proceeds to S102. If the special shooting mode is set, the process proceeds to S106. If the simultaneous shooting mode is set, the process proceeds to S110. In the present embodiment, when the system is activated and the display mode is not set by the operator, the normal imaging mode is set as the initial value.

  If it is determined in S101 that the normal shooting mode is set (S102), the system controller 202 drives the motor 214 via the driver 216, and rotates so that the optical filter F1 is disposed in the illumination optical path. The filter turret 212 is rotated by a predetermined angle. When the optical filter F1 is disposed in the illumination optical path, the subject is irradiated with white light. Next, the process proceeds to S103.

  In S103, the solid-state image sensor 108 receives reflected light from the subject irradiated with white light and converts it into an imaging signal. The imaging signal is sent to the preamplifier 110, the endoscope side signal processing circuit 112, and the processor side signal processing circuit 220. The system controller 202 controls the processor-side signal processing circuit 220 so that the first video IM1 is displayed on the monitor 300. In S103, the brightness setting parameters (that is, the aperture value of the diaphragm 213, the electronic shutter speed of the solid-state imaging device 108, the amplification factor (analog gain) of the preamplifier 110, and the amplification factor (digital) of the endoscope side signal processing circuit 112 are used. For the gain)), a preset initial value is used. Next, the process proceeds to S104.

  In step S <b> 104, the system controller 202 drives the diaphragm 213 via the motor 215 in order to make the first video IM <b> 1 displayed on the display screen of the monitor 300 appropriate brightness. Specifically, the system controller 202 obtains an average brightness (luminance) of the first video IM1, and stops the aperture so that the brightness becomes a brightness setting value (first brightness) preset by the operator. 213 is adjusted. As a result, a normal image having a desired brightness is displayed on the display screen of the monitor 300. As described above, the brightness setting value of the first image IM1 is changed and the brightness of the first image IM1 is adjusted by the brightness adjustment operation on the front operation unit 218 or the hand operation unit of the electronic scope 100 by the surgeon. Can do. Next, the process proceeds to S105.

  In S105, the system controller 202 determines whether the display mode has been changed or the display end operation has been performed by the operator operating the front panel 218 or the display mode setting button 114 (that is, the procedure end operation). Is determined). If the display mode change or display end operation has not been performed (S105: NO), the process returns to S103, and the processes from S103 to S105 are repeatedly executed. As a result, the first video IM1 is sequentially updated and displayed on the monitor 300. On the other hand, when the display mode is changed or the display end operation is performed (S105: YES), the process proceeds to S120.

  If it is determined in S101 that the special photographing mode is set (S106), the system controller 202 drives the motor 214 via the driver 216, and the rotary filter is arranged so that the optical filter F2 is disposed in the illumination optical path. The filter turret 212 is rotated by a predetermined angle. When the optical filter F2 is disposed in the illumination optical path, the subject is irradiated with special light. Next, the process proceeds to S107.

  In S107, the solid-state image sensor 108 receives the reflected light from the subject irradiated with the special light and converts it into an imaging signal. The imaging signal is sent to the preamplifier 110, the endoscope side signal processing circuit 112, and the processor side signal processing circuit 220. The system controller 202 controls the processor-side signal processing circuit 220 so that the second video IM2 is displayed on the monitor 300. In S107, the luminance setting parameters (that is, the aperture value of the diaphragm 213, the electronic shutter speed of the solid-state image sensor 108, the amplification factor (analog gain) of the preamplifier 110, and the amplification factor (digital) of the endoscope side signal processing circuit 112 are used. For the gain)), a preset initial value is used. Next, the process proceeds to S108.

  In S108, the system controller 202 drives the diaphragm 213 via the motor 215 in order to make the second video IM2 displayed on the display screen of the monitor 300 appropriate brightness. Specifically, the system controller 202 obtains the average brightness (luminance) of the second video IM2, and stops the aperture so that the brightness becomes a brightness setting value (second brightness) preset by the operator. 213 is adjusted. As a result, a special image having a desired brightness is displayed on the display screen of the monitor 300. Note that, as described above, the brightness setting value of the second image IM2 is changed and the brightness of the second image IM2 is adjusted by the brightness adjustment operation on the front operation unit 218 or the hand operation unit of the electronic scope 100 by the surgeon. Can do. Next, the process proceeds to S109.

  In S109, the system controller 202 determines whether the display mode has been changed or the display end operation has been performed by the operator operating the front panel 218 or the display mode setting button 114 (that is, the procedure end operation). Is determined). When the display mode change or display end operation has not been performed (S109: NO), the process returns to S107, and the processes from S107 to S109 are repeatedly executed. As a result, the second video IM2 is sequentially updated and displayed on the monitor 300. On the other hand, when the display mode is changed or the display end operation is performed (S109: YES), the process proceeds to S120.

  If it is determined in S101 that the simultaneous shooting mode is set (S110), the system controller 202 drives the motor 214 via the driver 216, and rotates so that the optical filter F1 is disposed in the illumination optical path. The filter turret 212 is rotated by a predetermined angle. When the optical filter F1 is disposed in the illumination optical path, the subject is irradiated with white light. Next, the process proceeds to S111.

  In S111, the solid-state image sensor 108 receives the reflected light from the subject irradiated with white light and converts it into an imaging signal. The imaging signal is sent to the preamplifier 110, the endoscope side signal processing circuit 112, and the processor side signal processing circuit 220. The system controller 202 controls the processor-side signal processing circuit 220 so that the first video IM1 is displayed on the left side of the monitor 300. In S111, the brightness setting parameters (that is, the aperture value of the diaphragm 213, the electronic shutter speed of the solid-state imaging device 108, the amplification factor (analog gain) of the preamplifier 110, and the amplification factor (digital) of the endoscope side signal processing circuit 112 are displayed. For the gain)), a preset initial value is used. Next, the process proceeds to S112.

  In S <b> 112, the system controller 202 drives the diaphragm 213 via the motor 215 in order to make the first video IM <b> 1 displayed on the left side of the display screen of the monitor 300 appropriate brightness. Specifically, the system controller 202 obtains the average brightness (luminance) of the first video IM1, and sets the aperture 213 so that this brightness becomes the brightness (first brightness) preset by the operator. adjust. As a result, a normal image having a desired brightness is displayed on the left side of the display screen of the monitor 300, as in S104. Next, the process proceeds to S114.

従って、システムコントローラ２０２は、Ｓ１１２で設定した絞り２１３の設定値、第１映像ＩＭ１の輝度設定値、第２映像ＩＭ２の輝度設定値、光学フィルタＦ１及びＦ２の透過率を取得し、上記の式に基づいて、第２映像ＩＭ２の輝度設定パラメータの変更度合いＸを求める。そして、求められた第２映像ＩＭ２の輝度設定パラメータの変更度合いＸに基づいて、第２映像ＩＭ２の輝度設定パラメータ、すなわち、絞り２１３の絞り値、固体撮像素子１０８の電子シャッタスピード、プリアンプ１１０の増幅率（アナログゲイン）及び内視鏡側信号処理回路１１２の増幅率（デジタルゲイン）の少なくともいずれか１つを変更する。例えば、本実施形態においては、光学フィルタＦ２の透過率は光学フィルタＦ１の透過率の５０％となっているため、第１映像ＩＭ１の輝度設定値と第２映像ＩＭ２の輝度設定値を同一とすると、Ｓ１１２で設定した絞り２１３の絞り値から求まる光量が２倍となるように第２映像ＩＭ２の輝度設定パラメータを変更すれば良いこととなる。ここで、Ｓ１１２で設定した絞り２１３の絞り値は、照明光の光量を表すことに他ならないため、絞り２１３の絞り値、固体撮像素子１０８の電子シャッタスピード、プリアンプ１１０の増幅率（アナログゲイン）及び内視鏡側信号処理回路１１２の増幅率（デジタルゲイン）の少なくともいずれか１つが２倍となるように変更する。 In S114, the system controller 202 sets the second video IM2 based on the setting value of the diaphragm 213 set in S112, the luminance setting value of the first video IM1 and the luminance setting value of the second video IM2 set by the operator. Change the brightness setting parameter. Specifically, the brightness of the lamp 208 is L, the transmittance of the optical filter F1 is F ₁ (%), the transmittance of the optical filter F2 is F ₂ (%), the brightness setting value of the first video IM1 is P1, When the brightness setting value of the second image IM2 is P2, the setting value of the aperture 213 set in S113 is A (%), and the change degree of the brightness setting parameter of the second image IM2 is X (%), the relationship of the following equations Is established.

Therefore, the system controller 202 acquires the setting value of the diaphragm 213, the luminance setting value of the first video IM1, the luminance setting value of the second video IM2, and the transmittances of the optical filters F1 and F2 set in S112, and the above formula Based on the above, the change degree X of the brightness setting parameter of the second video IM2 is obtained. Then, based on the obtained change degree X of the luminance setting parameter of the second video IM2, the luminance setting parameter of the second video IM2, that is, the aperture value of the diaphragm 213, the electronic shutter speed of the solid-state image sensor 108, the preamplifier 110 At least one of the amplification factor (analog gain) and the amplification factor (digital gain) of the endoscope side signal processing circuit 112 is changed. For example, in this embodiment, since the transmittance of the optical filter F2 is 50% of the transmittance of the optical filter F1, the luminance setting value of the first video IM1 and the luminance setting value of the second video IM2 are the same. Then, the luminance setting parameter of the second video IM2 may be changed so that the amount of light obtained from the aperture value of the aperture 213 set in S112 is doubled. Here, since the aperture value of the aperture 213 set in S112 represents nothing but the amount of illumination light, the aperture value of the aperture 213, the electronic shutter speed of the solid-state image sensor 108, and the amplification factor (analog gain) of the preamplifier 110. And at least one of the amplification factors (digital gains) of the endoscope side signal processing circuit 112 is changed to double.

  Any parameter may be changed or a plurality of parameters may be combined. However, when the set value is increased (that is, the gain is increased) in this way, the amplification factor (analog gain) of the preamplifier 110 or When the amplification factor (digital gain) of the endoscope side signal processing circuit 112 is increased, the noise component of the signal increases and SN deteriorates. Therefore, when it is desired to reduce the noise component of the signal, (1) the aperture value of the diaphragm 213, (2) the electronic shutter speed of the solid-state image sensor 108, (3) the amplification factor (digital gain) of the endoscope side signal processing circuit 112 (4) It is preferable to change the order of priority of the amplification factor (analog gain) of the preamplifier 110. When the set value is decreased (that is, the gain is decreased), (1) the electronic shutter speed of the solid-state image sensor 108, (2) the amplification factor (digital gain) of the endoscope side signal processing circuit 112, (3) It is preferable to change the priority of the amplification factor (analog gain) of the preamplifier 110 so that the aperture value of the aperture 213 is not changed. When it is desired to suppress image blur rather than the noise component of the signal, (1) the aperture value of the diaphragm 213, (2) the amplification factor (digital gain) of the endoscope side signal processing circuit 112, and (3) the preamplifier 110 It is preferable to change the gain (analog gain) and (4) the priority order of the electronic shutter speed of the solid-state image sensor 108. Thus, the change order of the brightness setting parameters of the second video IM2 in the present embodiment can be configured to be changeable according to the situation.

  Note that if the aperture value of the aperture 213 is changed in S114, the aperture value of the aperture 213 once set in S112 is changed, so that it is necessary to change the luminance setting parameter of the first video IM1. Specifically, in the above example, the aperture value of the aperture 213 is changed so that the amount of illumination light is doubled, so that the aperture of the first video IM1 is halved. The brightness setting parameters other than the aperture value of 213 are changed. For example, when the initial value of the electronic shutter speed of the solid-state image sensor 108 is set to 1/60 seconds, it is set to 1/120 seconds. As a result, the luminance of the first video IM1 becomes the same as the luminance adjusted in S112. When changing the luminance setting parameter of the first video IM1, (1) the electronic shutter speed of the solid-state image sensor 108, (2) the amplification factor (digital gain) of the endoscope side signal processing circuit 112, (3) the preamplifier The aperture value is changed according to the priority of the amplification factor (analog gain) of 110, and the aperture value of the aperture 213 is not changed.

  Thus, since the brightness setting parameter of the second video IM2 is adjusted by this process, the second video IM2 is displayed at a predetermined brightness (that is, the brightness setting value of the second video IM2) in the subsequent process. The Next, the process proceeds to S115.

  In S115, the system controller 202 drives the motor 214 via the driver 216, and rotates the rotary filter turret 212 so that the optical filter F2 is disposed in the illumination optical path. Next, the process proceeds to S116.

  In S116, the system controller 202 controls the processor side signal processing circuit 220 so that the second video IM2 is displayed on the right side of the monitor 300. Although the transmittance of the optical filter F2 is different from the transmittance of the optical filter F1, as described above, the brightness setting parameter of the second image IM2 is adjusted so as to eliminate this difference by the process of S114. Therefore, by this process, the second video IM2 having a predetermined luminance (that is, the luminance setting value of the second video IM2) is displayed on the right side of the display screen of the monitor 300. Then, after displaying the second video IM2 for one frame, the process proceeds to S119.

  In S119, the system controller 202 determines whether the display mode has been changed or the display end operation has been performed by the operator operating the front panel 218 or the display mode setting button 114 (that is, the procedure end operation). Is determined). If the display mode change or display end operation has not been performed (S119: NO), the process returns to S110, and S110 to S119 are repeatedly executed. That is, normal light and special light are irradiated to the subject for each frame, and the first video IM1 and the second video IM2 on the monitor 300 are alternately updated and displayed. On the other hand, when the display mode is changed or the display end operation is performed (S119: YES), the process proceeds to S120.

  In S120, the system controller 202 determines whether a display end operation has been performed by the operator operating the front panel 218 or the display mode setting button 114 (ie, a procedure end operation has been performed). When the display end operation is performed (S120: YES), the endoscopic image observation process ends. On the other hand, when the display end operation is not performed (S120: NO), the process returns to S101, and the processes from S101 to S120 are repeatedly executed.

  As described above, in the endoscopic image observation process of the present embodiment, the first video IM1 or the second video IM2 is monitored at a constant brightness by adjusting the diaphragm 213 in the normal photographing mode or the special observation mode. Feedback control is performed so as to be displayed at 300. Further, in the simultaneous observation mode, the aperture 213 is adjusted in one frame of the first video IM1, and the brightness setting parameter of the second video IM2 is changed to a predetermined value, so that the second image simultaneously displayed on the monitor 300 is displayed. The first video IM1 and the second video IM2 are controlled so as to have a predetermined luminance. Therefore, the surgeon does not need to adjust the brightness of each image during the procedure.

  The above is the description of the present embodiment, but the present invention is not limited to the configuration of the above-described embodiment, and various modifications are possible within the scope of the technical idea of the invention. For example, in the present embodiment, the first video IM1 and the second video IM2 are simultaneously displayed on one monitor 300 in the simultaneous shooting mode. However, the present invention is not limited to this configuration. The first video IM1 and the second video IM2 may be configured to be displayed on separate monitors. In this case, the image composition circuit 226 is unnecessary.

  In the present embodiment, the first video IM1 has been described as a normal image, and the second video IM2 has been described as a special image. For example, normal images having different luminance setting values are referred to as a first video IM1 and a second video IM2, respectively. It is also possible to set. According to such a configuration, it is possible to perform a comparative diagnosis while simultaneously displaying two images with different brightness on the monitor 300.

  In the present embodiment, the brightness setting value of the first video IM1 and the brightness setting value of the second video IM2 are configured to be changed by the surgeon. However, the optimal brightness setting value depends on the type of illumination light. It can also be configured to be set.

  In the present embodiment, the diaphragm 213 is adjusted using the average luminance value of the first image IM1 or the second image IM2 (so-called average metering). For example, a known peak metering is used. It is good. It is also possible to apply different metering methods, dimming methods, and gamma correction tables for the first video IM1 and the second video IM2.

(Endoscopic image observation processing according to the second embodiment)
FIG. 5 is a flowchart of an endoscopic image observation process executed by the electronic endoscope system according to the second embodiment of the present invention. In the present embodiment, for each of the first video IM1 and the second video IM2, well-known dimming parameters (photometry method (average photometry or peak photometry), photometry area (full area photometry, center-weighted photometry or spot photometry), This is different from the electronic endoscope system 1 according to the first embodiment in that the gamma correction table (brightness level) can be set.

  Parameters relating to the photometric area are parameters for performing area setting for calculating the luminance value of the current image (that is, the first video IM1 or the second video IM2) (that is, setting the photometric target area) It is selected from area metering, center-weighted metering or spot metering. When all-area metering is set, the processor-side signal processing circuit 220 divides the image into a plurality of areas and sets each area in each area. Weighting is set, and the entire area is subject to photometry. When spot photometry is set, the processor-side signal processing circuit 220 sets only a predetermined area of the image as a photometric target.

  The parameter relating to the photometry method is a parameter that defines a calculation method for calculating the luminance value of the current image, and is selected from average photometry or peak photometry. The processor-side signal processing circuit 220 performs, for example, a moving average to perform smoothing processing on the image data of the solid-state imaging device 108 corresponding to the area set as the photometric target area, and when the average photometry is set, A luminance value is calculated by obtaining an average value of the image data after the smoothing process. Further, when peak photometry is set, the processor-side signal processing circuit 220 obtains a peak value of the image data after the smoothing process and calculates a luminance value.

  The parameter relating to the brightness level is a parameter for setting the target luminance value of the image, and is set in, for example, five levels of -2, -1, 0, 1, and 2. In the dimming process using the diaphragm 213, the processor-side signal processing circuit 220 sets a predetermined reference value (that is, a luminance setting value) according to the set brightness level, and the luminance of the current image described above. The diaphragm 213 is controlled so that the value becomes a predetermined reference value.

  The parameter relating to the gamma correction table is a parameter for specifying the gamma correction table to be used. The gamma correction table includes values of image data (that is, luminance values) input from the endoscope side signal processing circuit 112 to the processor side signal processing circuit 220 and luminance values of images output from the processor side signal processing circuit 220. It is a table that defines the relationship (assignment). For example, the table for outputting the image data value input to the processor side signal processing circuit 220 as it is without correction, and the image data input to the processor side signal processing circuit 220 are improved so that the dark portion can be easily seen. One table desired by the surgeon is selected from a plurality of tables, such as a table in which a large output luminance value is assigned to a low value. The processor-side signal processing circuit 220 corrects and outputs the value of the input image data according to the set gamma correction table.

  When the dimming parameters as described above are set for each of the first video IM1 and the second video IM2, the luminance of the first video IM1 and the luminance of the second video IM2 are different. In the electronic endoscope system of the present embodiment, even when the dimming parameter of the first video IM1 and the dimming parameter of the second video IM2 are set differently in this way, the first video IM1 and The second video IM2 is controlled to have a predetermined luminance.

  The dimming parameters of the first video IM1 and the second video IM2 of the present embodiment are input by the operator operating the front panel 218, set in the processor-side signal processing circuit 220, and recorded in the memory 203. However, the configuration of the electronic endoscope system according to this embodiment is the same as that of the electronic endoscope system 1 according to the first embodiment. Omitted.

  Further, as shown in FIG. 5, the endoscope image observation process of the present embodiment is different from the endoscope image observation process according to the first embodiment in the processes of S210 to S219 in the simultaneous photographing mode. The different points will be described in detail.

  If it is determined in S101 that the simultaneous shooting mode is set (S210), the system controller 202 drives the motor 214 via the driver 216, and rotates so that the optical filter F1 is disposed in the illumination optical path. The filter turret 212 is rotated by a predetermined angle. When the optical filter F1 is disposed in the illumination optical path, the subject is irradiated with white light. Next, the process proceeds to S211.

  In S211, the solid-state image sensor 108 receives reflected light from the subject irradiated with white light and converts it into an imaging signal. The imaging signal is sent to the preamplifier 110, the endoscope side signal processing circuit 112, and the processor side signal processing circuit 220. The system controller 202 controls the processor-side signal processing circuit 220 so that the first video IM1 is displayed on the left side of the monitor 300. In S211, the brightness setting parameters (that is, the aperture value of the diaphragm 213, the electronic shutter speed of the solid-state image sensor 108, the amplification factor (analog gain) of the preamplifier 110, and the amplification factor (digital) of the endoscope side signal processing circuit 112 are used. (Gain)) is set to a preset initial value, and a dimming parameter (that is, photometry algorithm (average photometry or peak photometry), photometry area (full-area photometry, center-weighted photometry or spot photometry), gamma correction table, As for (brightness level), a setting value set in advance by the operator is set in the processor-side signal processing circuit 220. Next, the process proceeds to S212.

  In S <b> 212, the system controller 202 drives the diaphragm 213 via the motor 215 in order to make the first video IM <b> 1 displayed on the left side of the display screen of the monitor 300 appropriate brightness. For example, when the metering algorithm of the first image IM1 is set to “average metering” and the metering area is set to “all-area metering”, the system controller 202 determines the brightness of this condition (that is, the first image (Average luminance of all areas of IM1) is acquired from the processor-side signal processing circuit 220, and the diaphragm 213 is adjusted so that this luminance becomes a luminance (first luminance) preset by the operator. As a result, a normal image with desired brightness and dimming conditions (dimming parameters) is displayed on the left side of the display screen of the monitor 300. Next, the process proceeds to S214.

  In S214, the system controller 202 drives the motor 214 via the driver 216, and rotates the rotary filter turret 212 so that the optical filter F2 is disposed in the illumination optical path. Next, the process proceeds to S215.

  In S215, the system controller 202 sets the dimming parameter of the first video IM1 in the processor-side signal processing circuit 220, and captures the second video IM2 of one frame in this state and obtains the luminance value (hereinafter, obtained by S215). The luminance value of the obtained second video IM2 is referred to as “luminance value A”). Next, the process proceeds to S216.

  In S216, the system controller 202 sets the dimming parameter of the second video IM2 in the processor-side signal processing circuit 220, and captures the second video IM2 of one frame in this state and obtains the luminance value (hereinafter, obtained by S216). The luminance value of the obtained second video IM2 is referred to as “luminance value B”. Next, the process proceeds to S217.

  In S217, the system controller 202 obtains the ratio between the luminance value A and the luminance value B obtained in S215 and S216, and performs processing for changing the luminance setting parameter of the second video IM2 based on this value. As described above, the luminance value A is a luminance value based on the dimming parameter of the first video IM1, and is obtained through the optical filter F2. The luminance value B is a luminance value based on the dimming parameter of the second video IM2, and is obtained through the optical filter F2. Therefore, the ratio between the luminance value A and the luminance value B is nothing but an index representing the difference between the dimming parameter of the first video IM1 and the dimming parameter of the second video IM2. This process sets the luminance value of the second video IM2 based on the luminance of the first video IM1 by setting the luminance setting parameter of the second video IM2 based on the ratio between the luminance value A and the luminance value B. doing. For example, when the ratio between the brightness value A and the brightness value B is “2”, the brightness setting parameter (other than the aperture value of the aperture 213) is set so that the amount of light obtained from the aperture value of the aperture 213 set in S212 is doubled. That is, at least one of the electronic shutter speed of the solid-state image sensor 108, the amplification factor (analog gain) of the preamplifier 110, and the amplification factor (digital gain) of the endoscope side signal processing circuit 112 is changed. In this way, even if the dimming parameter of the first video IM1 and the dimming parameter of the second video IM2 are different from each other by this process, the luminance adjustment according to each dimming parameter is automatically performed. Become. Next, the process proceeds to S218.

  In S218, the system controller 202 controls the processor-side signal processing circuit 220 so that the second video IM2 is displayed on the right side of the monitor 300. Similar to the first embodiment, the transmittance of the optical filter F2 is different from the transmittance of the optical filter F1, but as described above, the brightness setting parameter of the second image IM2 is set so as to eliminate this difference by the processing of S217. It has been adjusted. Therefore, by this process, the second video IM2 having a predetermined luminance corresponding to the dimming parameter is displayed on the right side of the display screen of the monitor 300. Then, after displaying the second video IM2 for one frame, the process proceeds to S219.

  In S219, the system controller 202 determines whether the display mode has been changed or the display end operation has been performed by the operator operating the front panel 218 or the display mode setting button 114 (ie, the procedure end operation). Is determined). When the display mode change or display end operation has not been performed (S219: NO), the process returns to S210, and S210 to S219 are repeatedly executed. That is, normal light and special light are irradiated to the subject for each frame, and the first video IM1 and the second video IM2 on the monitor 300 are alternately updated and displayed. On the other hand, when the display mode is changed or the display end operation is performed (S219: YES), the process proceeds to S120.

  As described above, according to the present embodiment, even if different dimming parameters are set for the first video IM1 and the second video IM2, it is possible to obtain the desired video for each of the first video IM1 and the second video IM2. The image of the brightness to be obtained is obtained.

  The above is the description of the present embodiment, but various modifications are possible as in the first embodiment. For example, in the present embodiment, the first video IM1 has been described as a normal image, and the second video IM2 has been described as a special image. For example, normal images having different dimming parameters are referred to as a first video IM1 and a second video IM2, respectively. It is also possible to set. According to such a configuration, it is possible to perform comparative diagnosis while simultaneously displaying two images with slightly different brightness on the monitor 300.

DESCRIPTION OF SYMBOLS 1 Electronic endoscope system 100 Electronic scope 108 Solid-state image sensor 112 Endoscope side signal processing circuit 200 Processor 202 System controller 203 Memory 204 Timing controller 212 Rotary filter turret 213 Diaphragm 220 Processor side signal processing circuit 222 Image processing circuit 224 Frame Memory 226 Image composition circuit 300 Monitor

Claims (12)

A light source that emits illumination light;
A light amount adjusting means for adjusting a light amount of the illumination light;
An electronic endoscope that images an object irradiated with the illumination light with an image sensor and outputs an image signal;
First image processing means for receiving the image signal, generating a first endoscope image having a luminance corresponding to a value of a first luminance setting parameter, and outputting the first endoscope image as a first video signal;
Second image processing means for receiving the image signal, generating a second endoscopic image having a luminance corresponding to a value of a second luminance setting parameter, and outputting the second endoscope image as a second video signal;
First luminance setting means for setting a target luminance of the first endoscopic image as a first luminance;
Second luminance setting means for setting a target luminance of the second endoscopic image as a second luminance;
Display means for receiving the first video signal and the second video signal and displaying the first endoscopic image and the second endoscopic image;
Brightness adjusting means for adjusting the value of the first brightness setting parameter and the value of the second brightness setting parameter;
With
The light amount adjusting means adjusts the light amount so that the luminance of the first endoscopic image becomes the first luminance,
The luminance adjusting unit is configured to set the light amount set by the light amount adjusting unit and a ratio between the first luminance and the second luminance so that the luminance of the second endoscope image becomes the second luminance. And changing the value of the second brightness setting parameter,
The electronic endoscope system, wherein the first image processing means and the second image processing means receive the image signal alternately every frame. The illumination light includes white light and predetermined narrowband light,
Further comprising illumination light switching means for switching between the white light and the predetermined narrowband light,
2. The electronic endoscope system according to claim 1, wherein the illumination light switching unit switches the white light and the predetermined narrow band light for each frame based on the image signal. The first image processing means receives the image signal when the white light is irradiated,
The electronic endoscope system according to claim 2, wherein the second image processing means receives the image signal when the predetermined narrow band light is irradiated.   The first luminance setting means sets the optimum luminance for the white light as the first luminance, and the second luminance setting means sets the optimum luminance for the predetermined narrow band light as the second luminance. The electronic endoscope system according to claim 3. The light amount adjusting means is a diaphragm mechanism arranged in the optical path of the illumination light,
The first brightness setting parameter and the second brightness setting parameter each include an aperture value of the aperture mechanism, an electronic shutter speed of the image sensor, and an amplification factor of the image signal. The electronic endoscope system according to claim 4. When the brightness adjustment means increases the brightness of the second endoscopic image when changing the value of the second brightness setting parameter, the brightness adjustment means changes the aperture value with a first priority, and the electronic shutter speed. Is changed with a second priority, the amplification factor is changed with a third priority, and the brightness of the second endoscopic image is reduced , the electronic shutter speed is changed with the first priority, The electronic endoscope system according to claim 5, wherein the amplification factor is changed with a second priority, and the aperture value is not changed.   The brightness adjusting means changes the electronic shutter speed or the amplification factor of the first brightness setting parameter according to the changed aperture value when the aperture value of the second brightness setting parameter is changed. The electronic endoscope system according to claim 5 or 6, characterized by the above-mentioned.   8. The electronic endoscope system according to claim 7, wherein the brightness adjusting unit changes the electronic shutter speed with priority over the amplification factor when the first brightness setting parameter is changed.   The electronic endoscope system according to any one of claims 1 to 8, wherein the first luminance and the second luminance are the same. An input means for receiving input from the user;
The first brightness setting means sets the first brightness in response to an input to the input means;
The electronic endoscope system according to any one of claims 1 to 9, wherein the second luminance setting unit sets the second luminance in accordance with an input to the input unit. A first dimming parameter defining a dimming condition of the first endoscopic image;
A second dimming parameter that defines dimming conditions for the second endoscopic image,
The light amount adjusting means adjusts the light amount so that the luminance of the first endoscopic image becomes the first luminance under the dimming condition of the first dimming parameter,
The brightness adjusting unit obtains the brightness of the second endoscope image under the light amount set by the light amount adjusting unit and the dimming condition of the first dimming parameter, and is set by the light amount adjusting unit. The luminance of the second endoscopic image is obtained under the dimming condition of the light amount and the second dimming parameter, and is set by the light amount adjusting unit instead of the ratio between the first luminance and the second luminance. The brightness of the second endoscope image obtained under the dimming condition of the light amount and the first dimming parameter, and the light amount and the second dimming parameter set by the light amount adjusting means. 11. The value of the second luminance setting parameter is changed based on a ratio with the luminance of the second endoscopic image obtained under a dimming condition. Electronic endoscope according to claim 1 Stem. A light source that emits illumination light;
A light amount adjusting means for adjusting a light amount of the illumination light;
An electronic endoscope that images an object irradiated with the illumination light with an image sensor and outputs an image signal;
First image processing means for receiving the image signal, generating a first endoscope image having a luminance corresponding to a value of a first luminance setting parameter, and outputting the first endoscope image as a first video signal;
Second image processing means for receiving the image signal, generating a second endoscopic image having a luminance corresponding to a value of a second luminance setting parameter, and outputting the second endoscope image as a second video signal;
Display means for receiving the first video signal and the second video signal and displaying the first endoscopic image and the second endoscopic image;
Brightness adjusting means for adjusting the value of the first brightness setting parameter and the value of the second brightness setting parameter;
With
The light amount adjusting means adjusts the light amount so that the luminance of the first endoscopic image becomes a predetermined luminance,
The brightness adjusting unit changes the value of the second brightness setting parameter based on the light amount set by the light amount adjusting unit so that the brightness of the second endoscopic image becomes the predetermined brightness. ,
The electronic endoscope system, wherein the first image processing means and the second image processing means receive the image signal alternately every frame.

Images