JP6204116B2 - Electronic endoscope system - Google Patents

Description

  The present invention relates to an electronic endoscope system for observing a subject such as a lesion.

  In the medical device field, an electronic endoscope system that facilitates diagnosis of a lesion by simultaneously performing observation using light in different wavelength ranges is known. A specific configuration of this type of electronic endoscope system is described in Patent Document 1, for example.

  In the electronic endoscope system described in Patent Document 1, the system control circuit (42) introduces white light into the light guide (16) in the first field of the odd-numbered frame and the second field of the even-numbered frame that follows. At the same time, excitation light is introduced into the light guide 16 in the second field of the odd-numbered frame and in the first field of the subsequent even-numbered frame. The pre-stage processing circuit (431) overwrites each memory area (432a to d) with the video signal obtained in each field of the odd-numbered frame and each field of the even-numbered frame. In the first field of each frame, the scan converter (435) reads and combines the video signals of the normal color image and the fluorescence image from the memory areas (432a, c), respectively, and in the second field of each frame, the memory area The video signals of the normal color image and the fluorescence image are read out from each of (432d, b) and combined. As a result, the normal color image and the fluorescent image are simultaneously displayed in one screen in a state in which the reduction in resolution in the vertical direction is suppressed.

JP 2005-319213 A

  In Patent Document 1, the normal color image and fluorescent image of each field are always continuously updated twice (for example, the first field of the odd numbered frame and the next even numbered frame until it is updated with a new field image). Subsequent to the first field, or subsequent to the second field of the odd-numbered frame and the second field of the next even-numbered frame), the substantial refresh rate in the field unit is low. For this reason, for example, when the amount of movement of the subject is large (fast), there is a drawback that the afterimage feeling and the moving image blur are conspicuous.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress afterimages and moving image blurring when the amount of motion of a subject is large (fast) while suppressing a decrease in vertical resolution. It is to provide an electronic endoscope system capable of performing the above.

  An electronic endoscope system according to an embodiment of the present invention includes a light source unit that cyclically emits first light and second light having different spectral characteristics and light amounts at a timing synchronized with a predetermined field rate. The first light is emitted continuously for two or more fields, and the field image of the subject irradiated with the first light is generated as the first field image, and the subject irradiated with the second light. Field image generating means for generating the field image of the first field image as a second field image, display means for simultaneously displaying the generated first field image and second field image at a predetermined field rate within one screen, and a subject Motion amount detecting means for detecting the amount of motion, and motion amount determining means for determining whether or not the detected motion amount is large. The display means displays the first field image of the immediately preceding field on the screen in the missing field where the first field image is missing when the movement amount determination means determines that the movement amount of the subject is large, and the movement amount When the determination means determines that the amount of movement of the subject is small, the first field image of the field immediately before the previous field is displayed on the screen in the missing field.

In the present embodiment, when the amount of motion of the subject is large, by displaying the previous field image on the screen in the missing field, the afterimage feeling or the moving image blur that appears prominently when the amount of motion of the subject is large (fast). It can be suppressed. In addition, when the amount of movement of the subject is small, in the missing field, the field image immediately before the previous field is displayed on the screen, thereby avoiding a reduction in resolution in the vertical direction.

  For example, the motion amount detection means detects the motion amount of the subject based on the difference between the first field image of the immediately preceding field and the first field image of the field immediately before the immediately preceding field.

  The light source unit emits white light, a predetermined rotating plate having a first filter for filtering white light into the first light, and a second filter for filtering white light into the second light, and rotation. It is good also as a structure provided with the rotation drive part which inserts sequentially in the optical path of white light at the timing which synchronized each 1st and 2nd filter with the predetermined | prescribed field rate by rotating a board. The rotating plate has, for example, a configuration in which a first filter and a second filter are arranged side by side in an angular range corresponding to a field period in the circumferential direction, and only the first filter has two consecutive fields. They are arranged in an angle range corresponding to the above periods.

  The light source unit may include a replacement unit that switches the first light emission period and the second light emission period.

  The light source unit emits white light, a predetermined rotating plate having a first filter for filtering white light into the first light, and a second filter for filtering white light into the second light, and rotation. Rotating plate moving means for moving the plate in a direction perpendicular to the optical path of the white light, and rotating the rotating plate moved to a predetermined first or second position by the rotating plate moving means, the first and second It is good also as a structure provided with the rotation drive part which inserts each of these filters in the optical path of white light sequentially at the timing synchronized with the predetermined field rate. The rotating plate has, for example, a configuration in which the first filter and the second filter are arranged in two rows in the circumferential direction, and each filter is arranged in an angular range according to the field period, In one column, only the first filter is arranged in an angle range corresponding to a period of two or more consecutive fields, and in the other column, only the second filter is arranged in an angle range corresponding to a period of two or more consecutive fields. It has been. The rotation drive unit rotates the rotating plate moved to the predetermined first position by the rotating plate moving means, so that the first and second filters arranged in one row are synchronized with the predetermined field rate. Sequentially inserted into the optical path. The rotation drive unit rotates the rotating plate moved to the predetermined second position by the rotating plate moving means, so that the first and second filters arranged in the other row are synchronized with the predetermined field rate. Sequentially inserted into the optical path.

  According to the embodiment of the present invention, there is provided an electronic endoscope system capable of suppressing afterimage feeling and moving image blurring when the amount of motion of a subject is large (fast) while suppressing a decrease in resolution in the vertical direction.

It is a block diagram which shows the structure of the electronic endoscope system of embodiment of this invention. It is the front view which looked at the rotation filter part with which the processor of the embodiment of the present invention is provided from the condensing lens side. It is a sequence diagram which shows the processing timing of each phase regarding special light and normal light. It is a figure which shows the defect field complementation process performed in this embodiment with a flowchart. It is a block diagram which shows the structure of the electronic endoscope system of the modification of embodiment of this invention. It is the front view which looked at the rotation filter part with which the processor of the modification of embodiment of this invention is provided from the condensing lens side.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, an electronic endoscope system will be described as an example of an embodiment of the present invention.

[Overall configuration of electronic endoscope system 1]
FIG. 1 is a block diagram illustrating a configuration of an electronic endoscope system 1 according to the present embodiment. As shown in FIG. 1, the electronic endoscope system 1 includes an electronic scope 100, a processor 200, and a monitor 300.

  The processor 200 includes a system controller 202 and a timing controller 204. The system controller 202 executes various programs stored in the memory 203 and controls the entire electronic endoscope system 1 in an integrated manner. The system controller 202 is connected to the operation panel 218. The system controller 202 changes each operation of the electronic endoscope system 1 and parameters for each operation in accordance with an instruction from the user input from the operation panel 218. The timing controller 204 outputs a clock pulse for adjusting the operation timing of each unit to each circuit in the electronic endoscope system 1.

  The lamp 208 emits a white light beam L 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 white light beam L emitted from the lamp 208 is incident on the rotary filter unit 260.

  FIG. 2 is a front view of the rotary filter 260 as viewed from the condenser lens 210 side. The rotary filter unit 260 includes a rotary turret 261, a DC motor 262, a driver 263, and a photo interrupter 264. As shown in FIG. 2, the rotary turret 261 includes four optical filters, special light filters Fs1, Fs2, and Fs3, and a normal light filter Fn, arranged in order in the circumferential direction. Each optical filter has a fan shape that extends in an angle range (here, an angle range of about 90 °) corresponding to a field period (in this embodiment, 1/60 second).

  The driver 263 drives the DC motor 262 under the control of the system controller 202. The rotary filter unit 260 rotates the rotary turret 261 by the DC motor 262, so that two types of irradiation light (special light and white light, which are different from each other) from the white light beam L incident from the lamp 208, are obtained. One of the light) is taken out at a timing synchronized with imaging. Specifically, during the rotation operation, the rotary turret 261 sequentially takes out special light from the special light filters Fs1, Fs2, and Fs3 in each of the three consecutive field periods, and from the normal light filter Fn in the subsequent one field period. Normal light is taken out. The rotational position and rotational phase of the rotary turret 261 are controlled by detecting an opening (not shown) formed in the vicinity of the outer periphery of the rotary turret 261 with a photo interrupter 264.

  The special light filters Fs1 to Fs3 are optical filters having the same spectral characteristics, for example, a spectrum suitable for photographing a spectral image of a blood vessel structure in the vicinity of the surface layer (or a deep blood vessel structure, a specific lesion site, etc.). Has characteristics. The normal light filter Fn is a neutral density filter that attenuates the white light beam L, but may be replaced with a simple aperture (no optical filter) or a slit (no optical filter) that also functions as a diaphragm.

  Irradiated light extracted from the rotary filter unit 260 is collected by the condenser lens 210 and is limited to an appropriate amount of light through a blade stop (not shown), and enters an incident end of an LCB (Light Carrying Bundle) 102. Is done.

  Irradiation light incident on the LCB 102 from the incident end propagates through the LCB 102, exits from the exit end of the LCB 102 disposed at the tip of the electronic scope 100, and irradiates the subject via the light distribution lens 104. The subject is irradiated with special light during three consecutive field periods, and with normal light during the subsequent one field period. The return light from the subject irradiated with the irradiation light forms an optical image on the light receiving surface of the solid-state image sensor 108 via the objective lens 106.

  The solid-state image sensor 108 is an interlaced single-plate color CCD (Charge Coupled Device) image sensor having a complementary color checkered pixel arrangement. The solid-state image sensor 108 accumulates an optical image formed by each pixel on the light receiving surface as a charge corresponding to the amount of light, and generates each of complementary colors signals of yellow Ye, cyan Cy, green G, and magenta Mg. The complementary color signals of two pixels adjacent in the vertical direction are added, mixed, and output. Hereinafter, the mixed signal output from the solid-state image sensor 108 is referred to as an “imaging signal”. The solid-state image sensor 108 is not limited to a CCD image sensor, and may be a CMOS (Complementary Metal Oxide Semiconductor) image sensor or other types of imaging devices. The solid-state image sensor 108 may also be one equipped with a primary color filter (Bayer array filter).

  The switching timing between the special light and the normal light by the rotary filter unit 260 is synchronized with the switching timing of the imaging period (field period) in the solid-state imaging device 108. Therefore, the solid-state imaging device 108 receives special light during three consecutive field periods, generates and outputs an imaging signal of a special light observation image, and receives normal light and observes normal light during the subsequent one field period. An image pickup signal is generated and output. The solid-state image sensor 108 cyclically outputs an imaging signal of each observation image by repeating the above.

  A driver signal processing circuit 112 is provided in the connection portion of the electronic scope 100. Each image signal of the special light observation image and the normal light observation image is input to the driver signal processing circuit 112 from the solid-state image sensor 108 in a field cycle. The driver signal processing circuit 112 performs predetermined signal processing, such as color interpolation, matrix calculation, and Y / C separation, on the image signal input from the solid-state image sensor 108 to generate an image signal (luminance signal Y, color difference signal Cb, Cr) is generated, and the generated image signal is output to the pre-stage signal processing circuit 220 of the processor 200.

  The driver signal processing circuit 112 also accesses the memory 114 to read out the unique information of the electronic scope 100. The unique information of the electronic scope 100 recorded in the memory 114 includes, for example, the number and sensitivity of the solid-state image sensor 108, the operable field rate, the model number, and the like. The driver signal processing circuit 112 outputs the unique information read from the memory 114 to the system controller 202.

  The system controller 202 performs various calculations based on the unique information of the electronic scope 100 and generates a control signal. The system controller 202 controls the operation and timing of various circuits in the processor 200 using the generated control signal so that processing suitable for the electronic scope connected to the processor 200 is performed.

  The timing controller 204 supplies clock pulses to the driver signal processing circuit 112 in accordance with timing control by the system controller 202. The driver signal processing circuit 112 drives and controls the solid-state imaging device 108 at a timing synchronized with the field rate of the video processed on the processor 200 side in accordance with the clock pulse supplied from the timing controller 204.

  The pre-stage signal processing circuit 220 is a predetermined signal for each image signal (luminance signal Y and color difference signals Cb and Cr) of the special light observation image and the normal light observation image input from the driver signal processing circuit 112 in one field cycle. Processing is performed and output to the image memory 230.

  The image memory 230 has memory areas 230A to 230D. Each image signal output from the pre-stage signal processing circuit 220 is written (overwritten) in the memory areas 230A to 230D. Specifically, the special light observation image signal (displayed in the odd field) is written in the memory area 230A. Further, the special light observation image signal (displayed in the even field) is written in the memory area 230B. Further, the normal light observation image signal (displayed in the odd field) is written in the memory area 230C, and the normal light observation image signal (displayed in the even field) is written in the memory area 230D. Is written.

  Each image signal written in the memory areas 230 </ b> A to 230 </ b> D is sequentially read out in synchronization with the clock pulse from the timing controller 204 and is output to the subsequent signal processing circuit 240. The post-stage signal processing circuit 240 processes the image signals of the special light observation image and the normal light observation image output from the memory areas 230A to 230D to generate screen data for monitor display, and generates the generated monitor display screen data. Screen data is converted into a predetermined video format signal. The converted video format signal is output to the monitor 300. Thereby, the special observation image and the normal observation image of the subject are displayed on the display screen of the monitor 300.

  The user can set the display form of the observation image by operating the operation panel 218. As a display form of the observation image, for example, a form in which a special observation image of the same size and a normal observation image are arranged and displayed on one screen, a form in which one observation image is displayed on the main screen, and the other observation image is displayed on the sub-screen There is a form in which one observation image selected according to the user's operation is displayed in full screen. In addition, in the displayed observation image, information related to endoscopic observation (for example, the operator name, patient name, observation date and time, type of irradiation light used for observation, etc.) input through the operation panel 218 is superimposed. Can be displayed.

  FIG. 3 is a sequence diagram showing the processing timing of each phase related to special light and normal light when the special observation image and the normal observation image are displayed side by side on one screen. FIG. 3A shows the timing at which the subject (inside the body cavity) is irradiated with special light or normal light. FIGS. 3B to 3E show the writing timing of the imaging signals to the memory areas 230A to 230D, respectively. FIG. 3F shows the output / display timing of the special observation image (field image). FIG. 3G shows the output / display timing of the normal observation image (field image).

  In the present embodiment, as a premise, a time lag of one field occurs between the irradiation timing and the writing timing, and a time lag of one field occurs between the writing timing and the output / display timing. In each of FIGS. 3A to 3E, each timing is indicated by the notation of “the sign (ordinal number) of the filter of the rotary turret 261” for convenience.

For example, “Fs1 (1)” in FIG. 3A indicates the first irradiation timing with the special light extracted by the special light filter Fs1. Hereinafter, the special light extracted by the special light filter Fs1 is referred to as “special light L _Fs1 ”. The light extracted by the special light filters Fs2 and Fs3 and the normal light filter Fn are referred to as “special light L _Fs2 ”, “special light L _Fs3 ”, and “normal light L _Fn ”, respectively.

Further, for example, “Fs1 (1)” in FIG. 3B indicates the timing of writing the imaging signal of the subject irradiated with the special light L _Fs1 (first time) to the memory area 230A. Hereinafter, the imaging signal of the subject irradiated with the special light L _{Fs1 is referred} to as “imaging signal S _Fs1 ”. _Further , the imaging signals of the subject irradiated with the special lights L _Fs2 , L _Fs3 , and the normal light L _Fn are referred to as “imaging signal S _Fs2 ”, “imaging signal S _Fs3 ”, and “imaging signal S _Fn ”, respectively.

Further, for example, “Fs1 (1)” in FIG. 3F indicates the timing at which the special observation image generated from the imaging signal S _Fs1 (first time) is output / displayed on the monitor 300. Hereinafter, the special observation image generated by the imaging signal S _{Fs1 is referred} to as “special observation image I _Fs1 ”. The special observation images generated by the imaging signals S _Fs2 and S _Fs3 are referred to as “special observation image I _Fs2 ” and “special observation image I _Fs3 ”, respectively. The normal observation image generated by the imaging signal S _{Fn is referred} to as “normal observation image I _Fn ”.

[Generation of normal observation images]
The generation of the normal observation image will be described in detail with reference to FIG. The normal light filter Fn is inserted into the optical path of the white light beam L every four fields. Therefore, as shown in FIG. 3A, the subject is irradiated with normal light _LFn every four fields. The imaging signal S _Fn of the subject irradiated with the normal light L _Fn is written in both the memory areas 230C and 230D with a time lag of one field from the irradiation timing, as shown in FIGS. 3 (d) and 3 (e). It is. Memory areas 230C, respectively imaging signal _{S Fn} is written to 230D, it is converted into a video format signal by post-signal processing circuit 240, as shown in FIG. 3 (g), the odd field, the normal observation image I even field It is output and displayed on the monitor 300 as _Fn . In the present embodiment, the same normal observation image _IFn is displayed on the monitor 300 in four _consecutive fields.

[Generation of special observation images]
The generation of the special observation image will be described in detail with reference to FIG. The special light filters Fs1 to Fs3 are sequentially inserted into the optical path of the white light beam L during three consecutive field periods. Therefore, as shown in FIG. 3A, the subject is sequentially irradiated with the special lights L _Fs1 , L _Fs2 , and L _Fs3 during the three consecutive field periods.

The imaging signal S _Fs1 of the subject irradiated with the special light L _Fs1 is written in the memory area 230A with a time lag of one field from the irradiation timing, as shown in FIG. 3B. In the subsequent field period, as shown in FIG. 3 (c), the imaging signal _{S Fs2} of an object irradiated is written into the memory area 230B by the special light _{L Fs2.} In further subsequent field period, as shown in FIG. 3 (b), special light _{L Fs3} image signal _{S Fs3} of the subject illuminated by is written in the memory area 230A. In the subsequent field period, since the subject was irradiated with normal light instead of special light in the immediately preceding field, as shown in FIGS. 3B and 3C, the memory areas 230A and 230B There is no writing in either.

As shown in FIG. _3F , the imaging signals S _Fs1 , S _Fs2 , and S _Fs3 written in the memory area 230A or 230B are sequentially converted into video format signals by the _post- stage signal processing circuit 240, and the odd-field special The observation image _IFs1 , the even field special observation image _IFs2 , and the odd field special observation image _IFs3 are output and displayed on the monitor 300.

In the present embodiment, as shown in FIG. 3C, the imaging signal is not written to the memory area 230B in the field next to the field where the imaging signal _SFs3 is written. Therefore, in this state, the image of the next field (the even field of the same frame) of the special observation image I _Fs3 (odd field) is _lost . Hereinafter, this field is referred to as “missing field”.

For example, the special observation image _IFs3 (odd field) is continuously displayed for two fields (that is, the missing field is displayed), so that the field image can be omitted. However, in this case, since the same image is displayed in the odd field and the even field (missing field), the resolution in the vertical direction is lowered. In order to avoid a decrease in resolution in the vertical direction, it is conceivable that the special observation image _IFs2 (an even field one frame before) of the missing field is displayed again in the missing field. However, since an image two fields before is used, there is a possibility that afterimages and moving image blurs will appear remarkably when the amount of movement of the subject is large (fast). Therefore, in the present embodiment, by performing the defect field interpolation processing described below, it is possible to suppress afterimage feeling and moving image blurring when the amount of motion of the subject is large (fast) while suppressing a decrease in resolution in the vertical direction. It is possible.

[Defect field interpolation processing]
FIG. 4 is a flowchart showing the defect field complementing process.

[S11 in FIG. 4 (Detection of subject movement amount)]
In this processing step S11, the amount of movement of the subject is detected. As an example, an average value of differences between subject images is obtained. Specifically, for each pixel, a special observation image I _Fs3 (field (odd field) image immediately before the missing field) and a special observation image I _Fs1 (field immediately before the previous field (one frame before) The difference between the odd field and the image is calculated, and the calculated differences at each pixel are integrated. By dividing the integrated value by the total number of pixels, an average value of the difference between the subject images is obtained.

[S12 in FIG. 4 (Determination of the amount of movement of the subject)]
In this processing step S12, it is determined whether or not the amount of movement of the subject detected in processing step S11 (detection of the amount of movement of the subject) is greater than a predetermined threshold. The user can change the setting of the threshold value by operating the operation panel 218.

[S13 in FIG. 4 (completion of missing fields)]
When it is determined in the processing step S12 (determination of the amount of movement of the subject) that the amount of movement of the subject (average value of the difference between the subject images) is equal to or less than a predetermined threshold (S12 in FIG. 4: NO), the missing field Is complemented by an image two fields before the missing field (a special observation image _IFs2 and an image of an even field one frame before). That is, after the special observation image _IFs3 is displayed in the odd field, the special observation image _IFs2 (complementary image) is displayed in the subsequent even field (missing field). In this processing step S13, since different images are displayed in the odd field and the even field (missing field), the resolution in the vertical direction does not decrease in the frame.

[S14 in FIG. 4 (completion of missing fields)]
When it is determined in the processing step S12 (judgment of the amount of movement of the subject) that the amount of movement of the subject (average value of the difference between the subject images) is greater than a predetermined threshold (S12: YES in FIG. 4), the missing field is , The image immediately before the missing field (special observation image I _Fs3 ) is complemented. That is, on the monitor 300, the special observation image _IFs3 is displayed in the odd field, and then the special observation image _IFs3 (complementary image) is also displayed in the subsequent even field (missing field). In this processing step S14, the immediately preceding field image is displayed even in the missing field, so that an afterimage or moving image blur is less likely to appear even when the amount of movement of the subject is large (fast).

  As described above, in the present embodiment, it is possible to suppress the afterimage feeling and moving image blur when the amount of movement of the subject is large (fast) while suppressing a decrease in resolution in the vertical direction.

  The above is the description of the exemplary embodiments of the present invention. Embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical idea of the present invention. For example, the embodiment of the present application also includes an embodiment that is exemplarily specified in the specification or a combination of obvious embodiments and the like as appropriate. For example, the light source device is not limited to the configuration including the rotation filter unit. As an example, as in Patent Document 1, it may be replaced with a configuration including two independent light sources that emit light having different spectral characteristics.

  In the above embodiment, the light source device is built in the processor 200. However, in another embodiment, the processor 200 and the light source device may be separated. In this case, wired or wireless communication means for transmitting and receiving timing signals between the processor 200 and the light source device is provided.

In the above-described embodiment, it is determined whether the amount of movement of the subject is large or small based on a predetermined threshold, and the special observation image _IFs2 or _IFs3 is displayed in the missing field according to the determination result. In another embodiment, the special observation images I _Fs2 and I _Fs3 may be mixed at a predetermined ratio according to the amount of movement of the subject, and the mixed image may be displayed in the missing field. For example, when the average value of the difference between the subject images obtained in the processing step S11 (detection of the amount of movement of the subject) is a small value (for example, 1 and indicates that the amount of movement is small), the special observation image I _Fs2 and _IFs3 are mixed in a ratio of 2: 1. When the average value is a medium value (for example, 10 indicating that the amount of motion is a standard level), the special observation images _IFs2 and _IFs3 are mixed at a ratio of 1: 1. When the average value is a large value (for example, 20 and indicates that the amount of motion is large), the special observation images _IFs2 and _IFs3 are mixed at a ratio of 1: 2. Thus, in another embodiment, the mix ratio is higher special observation image I _Fs2 motion amount of the subject is small high, the larger the motion amount of the subject is special observation image I _Fs3 are mixed at a high rate.

  FIG. 5 is a block diagram illustrating a configuration of an electronic endoscope system 1M according to a modification of the above embodiment. As shown in FIG. 1, the electronic endoscope system 1M includes an electronic scope 100, a processor 200M, and a monitor 300. In the present modification, the same or similar components as those in the electronic endoscope system 1 of the above embodiment are denoted by the same or similar reference numerals, and the description thereof is simplified or omitted as appropriate.

  The processor 200M of this modification includes a rotation filter unit 260M. FIG. 6 is a front view of the rotary filter portion 260M as viewed from the condenser lens 210 side. The rotary filter unit 260M includes a rotary turret 261M, a DC motor 262, a driver 263, a photo interrupter 264, and a slide mechanism 265. As shown in FIG. 6, in the rotary turret 261M, four optical filters, special light filters Fs1, Fs2, and Fs3, and a normal light filter Fn are sequentially arranged in the circumferential direction. In addition, four optical filters of normal light filters Fn1, Fn2, Fn3, and special light filter Fs are sequentially arranged in the circumferential direction on the inner peripheral side of the four optical filters. The eight optical filters have a fan shape extending in an angle range (here, an angle range of about 90 °) corresponding to the field rate (60 fields / second in this embodiment).

  The slide mechanism 265 holds the rotary turret 261M so as to be slidable in a direction orthogonal to the optical path of the white light beam L (in the direction of arrow A in FIG. 6). Since the slide mechanism 265 has a known configuration, a specific configuration thereof is omitted. The rotary turret 261M is moved between an initial position and a slide position by a slide mechanism 265. The user can move the rotary turret 261M to the initial position or the slide position by operating the operation panel 218. When the rotary turret 261M is moved from the initial position to the slide position (or from the slide position to the initial position), the position of the lamp 208 (white light beam L) with respect to the rotary turret 261M is changed from the reference symbol PL to the reference symbol PL ′ ( Alternatively, shift from code PL ′ to code PL). Thereby, the filter group inserted in the optical path of the white light beam L is switched.

  Consider the case where the rotary turret 261M is in the initial position (the position of the lamp 208 (white light beam L) is denoted by PL). In this case, when the rotary turret 261M rotates, the optical filters Fs1, Fs2, and Fs3 for special light and the filter Fn for normal light are sequentially inserted into the optical path. For this reason, the subject is irradiated with special light during three consecutive field periods, and with normal light during the subsequent one field period, as in the above embodiment.

  Consider the case where the rotary turret 261M is at the slide position (the position of the lamp 208 (white light beam L) is denoted by PL '). In this case, when the rotary turret 261M rotates, the optical filters Fn1, Fn2, Fn3 and the special light filter Fs for normal light are sequentially inserted into the optical path. For this reason, the subject is irradiated with normal light during three consecutive field periods and with special light during the subsequent one field period.

In this modification, by switching the position of the rotary turret 261M, the irradiation period of the subject with normal light and the irradiation period of the subject with special light can be switched. When the rotary turret 261M is in the initial position, the same normal observation image I _Fn is displayed on the monitor 300 in four _{consecutive fields} and the special observation images I _Fs1 , I _Fs2 , and I _Fs3 are displayed on the monitor 300 as in the above embodiment. The complementary images (special observation images I _Fs2 or I _Fs3 ) are sequentially displayed. On the other hand, if the rotary turret 261M is in sliding position, the monitor 300, the same with the normal observation image _{I Fn1, I Fn2, I Fn3} , a complementary image (ordinary observation image _{I Fn2} or _{I Fn3)} are sequentially displayed The special observation image _IFs is displayed continuously for four fields.

1 Electronic Endoscope System 100 Electronic Scope 102 LCB
104 Light distribution lens 106 Objective lens 108 Solid-state imaging device 112 Driver signal processing circuit 114 Memory 200 Processor 202 System controller 203 Memory 204 Timing controller 206 Lamp power source igniter 208 Lamp 210 Condensing lens 218 Operation panel 220 Pre-stage signal processing circuit 230 Image memory 230A Normal odd memory area 230B Normal even memory area 230C Special light odd memory area 230D Special light even memory area 240 Rear signal processing circuit 260 Rotating filter unit 261 Rotating turrets Fs1 to Fs3 Special light filter Fn Normal light filter 262 DC motor 263 Driver 264 Photo interrupter 265 Slide mechanism

Claims (5)

A light source unit that cyclically emits first light and second light having different spectral characteristics and light amounts at a timing synchronized with a predetermined field rate, and only the first light continues for two or more fields. And what to inject
Field image generation means for generating a field image of the subject irradiated with the first light as a first field image and generating a field image of the subject irradiated with the second light as a second field image When,
Display means for simultaneously displaying the generated first field image and second field image at the predetermined field rate within one screen;
A movement amount detecting means for detecting a movement amount of the subject;
A motion amount determination means for determining whether or not the detected motion amount is large;
With
The display means includes
When the movement amount determination unit determines that the amount of movement of the subject is large, the first field image of the previous field is displayed on the screen in the missing field where the first field image is missing,
When the amount of movement of the subject is determined to be small by the movement amount determination means, the first field image of the field immediately before the previous field is displayed on the screen in the missing field.
Electronic endoscope system. The movement amount detecting means includes
Detecting the amount of movement of the subject based on the difference between the first field image of the previous field and the first field image of the field two fields before the previous field;
The electronic endoscope system according to claim 1. The light source unit is
A light source that emits white light;
A first filter for filtering the white light into the first light and a second filter for filtering the white light into the second light are arranged side by side in an angular range corresponding to the field period in the circumferential direction. A rotating plate, wherein only the first filter is arranged in an angle range corresponding to a period of two or more consecutive fields;
A rotation drive unit that sequentially inserts the first and second filters into the optical path of the white light at a timing synchronized with the predetermined field rate by rotating the rotating plate;
Comprising
The electronic endoscope system according to claim 1 or 2. The light source unit is
A replacement means for switching the first light emission period and the second light emission period;
The electronic endoscope system according to claim 1 or 2. The light source unit is
A light source that emits white light;
The first filter for filtering the white light into the first light and the second filter for filtering the white light into the second light are in two rows in the circumferential direction, and each filter is The rotating plates are arranged in an angle range corresponding to the field period, and only one of the first filters is arranged in one column, and the angle range corresponding to a period of two or more consecutive fields is arranged in the other column. Only the second filter is arranged in an angle range corresponding to a period of two or more consecutive fields,
Rotating plate moving means for moving the rotating plate in a direction orthogonal to the optical path of the white light;
By rotating the rotating plate in a state where the rotating plate is moved to a predetermined first position by the rotating plate moving means, the first and second filters arranged in the one row are moved to the predetermined row. By sequentially inserting into the optical path at a timing synchronized with a field rate, and rotating the rotating plate while the rotating plate is moved to a predetermined second position by the rotating plate moving means, A rotation drive unit that sequentially inserts the first and second filters arranged in the optical path at a timing synchronized with the predetermined field rate;
Comprising
The electronic endoscope system according to claim 1 or 2.

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