JP2005296454A - Electronic endoscope and light source device for electronic endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic endoscope and a light source device for the electronic endoscope which can easily execute light control and read the whole pixels to execute the frame composition of a high-resolution image with little image movement. <P>SOLUTION: The light source device for the electronic endoscope includes a light source, a rotary shutter which has a rotation shaft disposed in parallel with an optical axis of the light source and rotates around the rotation shaft to intercept the illumination light which comes from the light source by a shading section or to emit the light to a light guide through an aperture section, a shutter which is disposed between the light source and the light guide to make the central axis coincide with an optical axis of the light source, allows an incident ray pass through when it is open to full width and intercepts the passage of the incident ray when it is fully closed, and a controller to control a movement of the shutter, wherein a shading period of that the illumination light does not enter into the light guide is extended by full closing of the shutter with the control of the controller during a luminous period in which the illumination light goes out through the aperture section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electronic endoscope, and more particularly to a light source device for an electronic endoscope using both a rotary shutter and a shutter.

  In a conventional electronic endoscope, an endoscope recording apparatus disclosed in, for example, Japanese Patent Laid-Open No. 62-69222 has been proposed in order to perform appropriate light control. This apparatus has a rotary shutter having a rotation shaft capable of changing an inter-axis distance from an irradiation optical axis of an endoscope light source. This rotary shutter has a shape that produces a circumferential speed difference at each position in the radial direction when it rotates, and performs light control using the circumferential speed difference by changing the inter-axis distance.

  On the other hand, there has been an electronic endoscope for taking a still image disclosed in Japanese Patent Publication No. 7-85132. This electronic endoscope is provided with a circular rotation shielding plate, and a continuous light from a light source is provided on the rotation shielding plate through a narrow angle portion where the shielding time is slightly longer than the light dead time between fields in the solid-state imaging device. First and second exposure apertures that allow light to pass in the form of pulses are provided, and the end portion of the first field period and the second field are obtained from continuous light emitted from the light source by continuously rotating the rotary shielding plate. A rotary shutter is provided that generates a light pulse that is applied to the subject at the beginning of the period.

Further, as an electronic endoscope using a light source device that shields illumination light for a predetermined period, for example, there is one disclosed in Japanese Patent No. 3370871. This electronic endoscope has a rotation mode in which the motor for driving the rotary shutter is rotated and stopped to output illumination light through a predetermined light shielding period, and a stop mode in which the illumination light is emitted without being shielded. Yes. For this reason, it is possible to correspond to both of a method of reading while adding upper and lower pixel data that does not require a light shielding period and a method of reading all pixels that require a light shielding period.
JP-A-62-69222 Japanese Patent Publication No. 7-85132 Japanese Patent No. 3370871

In the apparatus described in Japanese Patent Laid-Open No. 62-69222 described above, although dimming is possible, it has been impossible to read out all pixels and incorporate a still image. Also, in the electronic endoscope described in Japanese Patent Publication No. 7-85132, when the first field and the second field are combined into a frame, the image is likely to be blurred. Furthermore, in the electronic endoscope described in Japanese Patent No. 3370871, the rotary shutter may be deteriorated by heat from illumination light.

  In order to solve the above problems, in the light source device for an electronic endoscope of the present invention, the light source and the rotation axis are arranged in parallel with the optical axis of the light source, and the light enters the light source by rotating around the rotation axis. Between the light source and the light guide, with the rotary shutter that blocks the illuminated light by the light shielding part or exits from the opening toward the light guide, and the central axis is aligned with the optical axis of the light source, and is fully open Includes a shutter that allows incident light to pass and blocks the progression of incident light in the fully closed state, and a controller that controls the operation of the shutter, and is controlled by the controller during a light emission period in which illumination light is emitted from the opening. It is characterized by extending the light shielding period in which illumination light does not enter the light guide by fully closing the shutter.

In the electronic endoscope of the present invention, an operation unit, an insertion unit extending from the operation unit and inserted into the observation target, a light guide inserted into the operation unit and the insertion unit, and a distal end thereof extending to the distal end of the insertion unit And a light source device that makes illumination light incident on the light guide. The light source device has a light source and a rotation axis arranged in parallel to the optical axis of the light source, and rotates from the light source by rotating about the rotation axis. Between the light source and the light guide, the central axis is aligned with the optical axis of the light source between the rotary shutter that blocks the incident illumination light by the light shielding part or exits from the opening to the light guide, and is fully opened. A shutter that blocks incident light in a fully closed state and a controller that controls the operation of the shutter, and a controller that controls the operation of the shutter during a light emission period in which illumination light is emitted from the opening. Illumination light to the light guide by the shutter fully closed is characterized by extending the light-shielding period without incident by the control of la.

The electronic endoscope or the electronic endoscope light source device includes an inter-axis distance changing unit that changes an inter-axis distance between the optical axis of the light source and the rotation axis, and the light shielding portion has an arc shape with a central angle of 240 degrees. The aperture has a shape in which the aperture ratio is changed in the circumferential direction corresponding to the diameter of the light beam incident on the rotary shutter from the light source, and the diameter of the light beam incident on the rotary shutter from the light source by the inter-axis distance changing means. It is preferable to change the amount of emitted light by changing the inter-axis distance in units of.

In the electronic endoscope of the present invention, the operation unit, the insertion unit extending from the operation unit and inserted into the observation target, the operation unit and the insertion unit are inserted, and the distal end thereof extends to the distal end of the insertion unit. A light guide; a light source device that makes illumination light incident on the light guide; an imaging unit that acquires an image of an observation site illuminated by the light source device as charges; and image data that accumulates the charges acquired by the imaging unit as image data A storage unit; an image processing device that develops image data stored in the image data storage unit into a frame image; and a display device that displays the frame image developed by the image processing device. The rotation axis is arranged in parallel with the optical axis of the light source, and the illumination light incident from the light source is blocked by the light shielding part or rotated from the opening by rotating around the rotation axis. It is arranged between the rotary shutter that emits toward the light source, and the light source and the light guide so that the central axis coincides with the optical axis of the light source. A shutter for blocking and a controller for controlling the operation of the shutter and the image pickup means, and the image pickup means is driven by either interlace driving or progressive drive under the control of the controller, and when the image pickup means is interlace driven. In each light emission period in which the illumination light is emitted from the opening, the imaging unit acquires an image of the observation site for one field as a charge, and the light shielding period is followed by the light shielding part in which the illumination light from the light source is blocked by the light shielding part. The pixel data adjacent to the top and bottom of the charge stored in the image pickup means is added to the image data storage means and transferred to the image data storage means. When the image pickup means is progressively driven, the image pickup means acquires two fields of images of the observation site as electric charges in the light emission period in which illumination light is emitted from the opening, and the light shielding section follows the light emission period from the light source. The charge accumulated in the imaging means is stored in the image data through the light blocking period in which the illumination light is blocked, the next light emission period in which the illumination light is blocked by the shutter, the light blocking period following the light emission period, and the light emission period subsequent thereto. It is characterized by being transferred and accumulated in the means.

  According to the present invention, an electronic endoscope and an electronic endoscope that can be easily dimmed with a simple configuration and that can read out all pixels and synthesize a frame of a high-quality image with less image blurring. A light source device can be provided.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, an electronic endoscope 1 according to the present embodiment includes an operation unit 11 held by an operator, an elongated and flexible insertion unit 12 extending outward from the operation unit 11, A light guide 20 that emits illumination light from the distal end of the insertion portion 12 to the outside, and a light source device 30 that is connected to the operation portion 11 via a connection connecting tube 13 are provided. The light guide 20 is inserted into the insertion portion 12, the operation portion 11, and the connection connecting tube 13 and connected to the light source device 30. A lamp (light source) 31 is disposed in the light source device 30, and illumination light emitted from the light source device 30 passes through the light guide 20 and is emitted from the distal end of the insertion portion 12 to the outside. Reflected light from the observation site by the illumination light enters the insertion portion 12 from the objective optical system 15 disposed at the distal end of the insertion portion 12 and is accumulated as a charge in a CCD (solid-state imaging device) 16. Here, the objective optical system 15 and the CCD 16 constitute an image pickup means, and the CCD 16 can select interlaced driving that handles one frame divided into odd and even fields and progressive driving that handles one frame at a time. It is an image sensor. All pixel data of the CCD 16 is divided into odd fields and even fields, transferred to a register (image data storage means) 17, developed into one frame by an image processing device 18 connected thereto, and displayed on a display device 19. (FIG. 2).

In addition to the lamp 31, the light source device 30 includes a rotation shaft 40 a parallel to the optical axis 31 a of the lamp 31, a rotary shutter 40 capable of dimming and blocking the illumination light emitted from the lamp 31, and rotation of the rotary shutter 40. A linear actuator (interaxial distance changing means) 33 that varies the interaxial distance X between the axis 40 a and the optical axis 31 a of the lamp 31, and a collection that collects the light emitted from the lamp 31 and enters the light guide 20. An optical lens 34 and a shutter 36 disposed between the condenser lens 34 and the rotary shutter 40 in a state where the central axis is disposed on the optical axis 31a.

The linear actuator 33 includes a base portion 33a extending perpendicularly to the optical axis 31a, and a motor 33b slidable (relatively movable) in the extending direction of the base portion 33a (the direction of the arrow in FIG. 1). The relative movement of the base portion 33a with respect to the motor 33b is automatically performed by the controller 35 connected to the luminance sensor 21 in accordance with the luminance information of the observation site and its surroundings detected by the luminance sensor 21 arranged at the distal end of the insertion portion 12. (FIG. 2). The rotation shaft 33c of the motor 33b is inserted and fixed in the center hole 41 of the rotary shutter 40 so as to coincide with the rotation shaft 40a. With this configuration, the rotary shutter 40 rotates by driving the motor 33b, and the inter-axis distance X between the optical axis 31a and the rotary shaft 40a can be changed by sliding the motor 33b on the base portion 33a. The shutter 36 is composed of a shutter having an existing configuration, and can take one of two states of being fully open or fully closed by a drive signal input from the controller 35. In the fully open state, all the incident light is allowed to pass, and in the fully closed state, the progress of the incident light is blocked. Note that the shutter 36 may be disposed not between the condenser lens 34 and the rotary shutter 40 but between the rotary shutter 40 and the lamp 31.

  Next, the configuration of the rotary shutter 40 will be described with reference to FIG. The rotary shutter 40 includes a light shielding portion 42 corresponding to an arc portion having a central angle of 240 ° among resin-made discs having a radius R40, and an opening 43 in which the remaining arc portion of the disc is shaped into a predetermined shape. And consist of The opening 43 is shaped such that when the rotary shutter 40 is rotated about the rotation shaft 40a, a predetermined opening ratio is obtained according to the distance from the rotation shaft 40a. Here, the radius R40 is five times the diameter D31 of the luminous flux 31b of the illumination light incident on the rotary shutter 40 from the lamp 31. The radius R40 may be any number (integer multiple) as long as it is twice or more the diameter D31.

  Here, the shape of the opening 43 will be described. The opening 43 includes a first opening 43a and a second opening 43b that are line-symmetric with respect to a straight line A that bisects the light-shielding portion 42 through the rotating shaft 40a. Since the second opening 43b is obtained by inverting the first opening 43a with respect to the straight line A, only the first opening 43a will be described in the following description.

The first opening 43a is configured by combining five curves. The first curve 43a1 is a curve on an imaginary circle 45a having a radius "radius R40-diameter D31" with the rotation axis 40a as the center, and a straight line B that forms 120 degrees with respect to the straight line A through the rotation axis 40a. Starting from the straight line B and continuing counterclockwise about the rotation axis 40a toward the straight line A to the end point 43a12 at a position of 30 degrees. The second curve 43a2 starts from the end point 43a12 of the curve 43a1 and starts rotating clockwise around the rotation axis 40a from the virtual circle 45b with the radius “radius R40-2 × diameter D31” centered on the rotation axis 40a and the straight line A. The intersection point with the straight line C rotated 15 degrees (60/4 degrees) to the straight line B is the end point 43a22. The third curve 43a3 starts from the end point 43a22 of the curve 43a2 and starts rotating clockwise around the rotation axis 40a from the virtual circle 45c centered on the rotation axis 40a and the radius “radius R40-3 × diameter D31” and the straight line A. The point of intersection 43a32 is the intersection point with the straight line D rotated to the straight line B by 7.5 ° (60/8 °) on the operation unit. The fourth curve 43a4 starts from the end point 43a32 of the curve 43a3, starts around the rotation axis 40a, rotates around the rotation axis 40a from the virtual circle 45c centered on the rotation axis 40a and the radius “radius R40-4 × diameter D31”. The intersection point with the straight line E rotated 3.75 degrees (60/16 degrees) to the straight line B is defined as an end point 43a42. The fifth curve 43a5 has the end point 43a42 of the curve 43a4 as the start point and the rotation axis 40a as the end point.

  The rotary shutter 40 having the above configuration is used by inserting the rotary shaft 33c into the center hole portion 41 and fixing them to each other. The rotary shutter 40 can shield the light emitted to the light shielding part 42 or the opening 43. Therefore, the amount of illumination light emitted from the rotary shutter 40 to the condenser lens 34 is set to a desired amount by changing the position of the opening 43 with respect to the optical axis 31a by moving the motor 33b relative to the base 33a. can do. That is, when the shape of the opening 43 is used, it is possible to adjust the light by changing the aperture ratio by changing the position of the rotary shutter 40 with respect to the optical axis 31a.

Specifically, the function of the rotary shutter 40 can be expressed as follows. First, the rotary shutter 40 is arranged so that the straight line A coincides with the moving direction of the motor 33b (the arrow direction in FIG. 1). In this state, the relative position between the optical axis 31a and the opening 43 can be changed by moving the motor 33b relative to the base 33a in five stages. That is, the light beam 31b having the optical axis 31a as the center is made to have the outermost position 47a in contact with both the outer periphery 46 of the rotary shutter 40 and the virtual circle 45a, the position 47b in contact with both the virtual circle 45a and the virtual circle 45b, and the virtual circle 45b. 47c that touches both the virtual circle 45c, the position 47d that touches both the virtual circle 45c and the virtual circle 45d, and the innermost position 47e that touches both the virtual circle 45d and the rotation axis 40a. Can do. In other words, the inter-axis distance X between the optical axis 31a and the rotation axis 40a is changed in units of the diameter of the light beam 31b incident on the rotary shutter 40 from the light source 31.

  When the rotary shutter 40 is rotated when the light beam 31b is disposed at the position 47a, the light emitted from the lamp 31 is shielded by the light shielding part 42 but not by the opening 43. On the other hand, when the rotary shutter 40 is rotated when the light beam 31b is disposed at the position 47b, the light emitted from the lamp 31 is shielded by the light shielding portion 42, but the opening 43 has the first opening. 43a and the second opening 43b are shielded from light, and are not shielded in the section between the first opening 43a and the second opening 43b. In this section, the illumination light is only half the time when the light beam 31b is disposed at the position 47a. Is emitted. Further, when the light beam 31b is disposed at each of the position 47c, the position 47d, and the position 47e, the light emitted from the lamp 31 is shielded by the light shielding portion 42, the first opening portion 43a, and the second opening portion 43b in any case. In the section between the first opening 43a and the second opening 43b, which gradually narrows in the order of the position 47c, the position 47d, and the position 47e, the illumination light is emitted to the condenser lens 34 side without being shielded from light. The emission times are 1/4, 1/8, and 1/16 times when the light beam 31b is disposed at the position 47a. With such a configuration, when the luminance of the observation site is low, the amount of illumination light can be increased by arranging the light beam 31b at the position 47a. Therefore, since the luminous flux 31b can be moved in the order of the position 47b, the position 47c, the position 47d, and the position 47e as the luminance of the observation region increases, the amount of illumination light can be reduced. It can be carried out.

  Next, an actual imaging display operation of the observation site will be described with reference to FIG. Prior to the observation, the insertion portion 12 is inserted into the body of the patient to be observed, and the tip thereof is directed to the observation site. When a start button (not shown) is pressed in this state, the shutter 36 is fully opened, illumination light is emitted from the lamp 31, the observation site is illuminated via the light guide 20, and the state of the observation site is displayed on the display device. Projected. At this time, the luminance sensor 21 detects the luminance of the observation site. If the luminance is low, the luminous flux 31b is arranged at a position 47a (FIG. 3) having a high aperture ratio or a position close thereto if the luminance is low. The controller 35 automatically moves the rotary shaft 33c relative to the motor 33b so that the light beam 31b is disposed at a position 47e having a low aperture ratio or a position close thereto.

  4A to 4E show the opening amount of the rotary shutter 40 (FIG. 4A) and the amount of current applied to the lamp 31 (FIG. 4B) when the luminance of the observation site is constant. The operating state of the shutter 36 (FIG. 4C), the amount of charge stored in the CCD 16 (FIG. 4D), and the transfer mode to the register 17 (FIG. 4E) are shown. There is no difference in timing even when the luminance of the part is not constant.

  In the present embodiment, the rotary shutter 40 rotates once in 1/30 seconds, and light is emitted from the opening 43 (light emission period) for 1/90 seconds of one rotation, and the light-shielding portion 42 is continued for 1/45 seconds. Thus, the illumination light from the lamp 31 is shielded (a light shielding period) (FIG. 4A). The lamp 31 increases in light quantity in synchronization with the light emission period determined by the operation of the rotary shutter 40 according to the drive signal input from the controller 35 (light quantity level H). On the other hand, the light quantity of the lamp 31 in the light shielding period is smaller than the light quantity in the light emission period (light quantity level L) (FIG. 4B). In this way, light emission and light shielding are repeated every 1/30 seconds. As will be described below, the CCD 16 operates in an interlaced manner unless the capture button 22 is pressed, and the reflected light from the observation site due to light emission is synchronized with the light emission timing of 1/90 seconds coming in 1/30 second period, One of the odd field (corresponding to cyan and yellow data in this embodiment) and the even field (corresponding to magenta and green data) is alternately accumulated as charge in the CCD 16 (FIG. 4C).

The charges accumulated in the CCD 16 are added to the upper and lower adjacent pixel data and transferred to the register 17 (FIG. 4D). This data transfer is started when the luminance sensor 21 detects that the illumination light from the lamp 31 is blocked, and based on this, the controller 35 outputs a signal instructing the transfer start to the register 17.

  The accumulation of the odd-numbered field and even-numbered field data in the CCD 16 and the transfer to the register 17 as described above are sequentially repeated in accordance with the light emission from the opening 43 or the light shielding by the light shielding unit 42. When the transfer of the odd-numbered field and even-numbered field pixel data obtained by the two light emission operations to the register 17 is completed, this data is immediately read out to the image processing device 18 and developed into one frame and displayed on the display device 19. The

  In the electronic endoscope 1 of the present embodiment, when the user operates the capture button 22 (see FIG. 2) connected to the controller 35 (FIG. 4 (f)), the CCD 16 is progressively moved by a control signal from the controller 35. Switching to driving, image data for one frame is accumulated during the next light emission period. All pixel data stored in the CCD 16 is started to be transferred to the register 17 in synchronization with the start of the next light-shielding period without adding pixel data adjacent to each other in the order of the odd field and the even field. .

  On the other hand, when the capture button 22 is operated, the shutter 36 that has been fully opened until then is closed by a control signal from the controller 35 in synchronization with the start of the next light shielding period. As shown in FIG. 4E, the shutter 36 takes 1/45 seconds until it is completely closed, and after the closing period of 1/90 seconds, it returns to the fully opened state over 1/45 seconds. When the shutter 36 is operated in this way, as shown in FIG. 4C, the light can be shielded during the second light emission period after the operation of the capture button 22 regardless of the operation of the rotary shutter 40. As a result, the light emission to the CCD 16 is blocked for 1/18 second after the first light emission period after the operation of the capture button 22, and all pixel data is divided into an odd field and an even field during this period and 1/15 second including the next light emission period. Thus, it is possible to secure a time for transferring in the order (FIG. 4D). When the transfer is completed, all pixel data is immediately read out to the image processing device 18 and developed into one frame and displayed on the display device 19. Thus, since one frame is synthesized using all pixel data, a high-quality image can be displayed.

After the operation of the capture button 22, when the transfer is completed, the CCD 16 automatically returns to the interlace drive. After that, unless the capture button 22 is operated, the reflected light from the observation site due to the light emission of the odd field and the even field is synchronized with the light emission timing of 1/90 second of the 1/30 second period by the operation of the rotary shutter 40. One is alternately accumulated as charge in the CCD 16. When the capture button 22 is operated again, the CCD 16 is switched to progressive driving, the shutter 36 is closed as described above, and all pixel data is transferred.

  Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the above embodiment, and can be improved or changed within the scope of the purpose of the improvement or the idea of the present invention.

It is the schematic which shows the internal structure of the electronic endoscope which concerns on embodiment of this invention. It is a block diagram which shows the structure of the electronic endoscope which concerns on embodiment of this invention. It is a top view which shows the structure of the rotary shutter which concerns on embodiment of this invention. It is a timing chart which shows operation | movement of the electronic endoscope which concerns on embodiment of this invention.

Explanation of symbols

1 Electronic endoscope 15 Objective optical system (imaging means)
16 CCD (imaging means)
17 register (image data storage means)
18 Image processing device 19 Display device 20 Light guide 30 Light source device 31 Lamp (light source)
31a Optical axis 33 Linear actuator (Inter-axis distance changing means)
36 Shutter 40 Rotary shutter 40a Rotating shaft 42 Light-shielding portion 43 Opening portion X Distance between axes

Claims (5)

A light source;
A rotary shaft whose rotation axis is arranged in parallel with the optical axis of the light source and rotates around the rotation axis so that the illumination light incident from the light source is blocked by the light blocking portion or emitted from the opening toward the light guide A shutter;
Between the light source and the light guide, a shutter is disposed so that a central axis coincides with an optical axis of the light source, allows incident light to pass in a fully open state, and blocks the progress of incident light in a fully closed state;
A controller for controlling the operation of the shutter;
With
In a light emission period in which illumination light is emitted from the opening, the light shielding period in which illumination light is not incident on the light guide is extended by fully closing the shutter under the control of the controller. Endoscopic light source device. An inter-axis distance changing unit is provided for changing an inter-axis distance between the optical axis of the light source and the rotation axis, the light shielding part has an arc shape with a central angle of 240 degrees, and the opening part extends from the light source to the rotary shutter. The aperture ratio is changed in the circumferential direction in correspondence with the diameter of the light beam incident on the light source, and the unit for changing the diameter of the light beam incident on the rotary shutter from the light source by the inter-axis distance changing unit. The light source device for an electronic endoscope according to claim 1, wherein the amount of emitted light is changed by changing a distance between the axes. An operation unit;
An insertion portion extending from the operation portion and inserted into the observation target;
A light guide that is inserted into the operation portion and the insertion portion, and whose tip extends to the tip of the insertion portion;
A light source device that makes illumination light incident on the light guide;
Have
The light source device has a light source and a rotation axis arranged in parallel with the optical axis of the light source, and rotates around the rotation axis to block illumination light incident from the light source by a light shielding portion or from an opening portion. Between the rotary shutter that emits light toward the light guide, and between the light source and the light guide, the central axis is arranged so as to coincide with the optical axis of the light source. Includes a shutter that blocks the progress of incident light and a controller that controls the operation of the shutter, and the shutter is fully closed under the control of the controller during a light emission period in which illumination light is emitted from the opening. Accordingly, the electronic endoscope is characterized by extending a light shielding period in which illumination light does not enter the light guide. An inter-axis distance changing unit is provided for changing an inter-axis distance between the optical axis of the light source and the rotation axis, the light shielding part has an arc shape with a central angle of 240 degrees, and the opening part extends from the light source to the rotary shutter. The aperture ratio is changed in the circumferential direction in correspondence with the diameter of the light beam incident on the light source, and the unit for changing the diameter of the light beam incident on the rotary shutter from the light source by the inter-axis distance changing unit. The electronic endoscope according to claim 3, wherein the amount of emitted light is changed by changing a distance between the axes. An operation unit;
An insertion portion extending from the operation portion and inserted into the observation target;
A light guide that is inserted into the operation portion and the insertion portion, and whose tip extends to the tip of the insertion portion;
A light source device that makes illumination light incident on the light guide;
Imaging means for acquiring an image of an observation site illuminated by the light source device as a charge;
Image data storage means for storing the charge acquired by the photographing means as image data;
An image processing device that develops image data stored in the image data storage means into a frame image;
A display device for displaying a frame image developed by the image processing device;
Have
The light source device has a light source and a rotation axis arranged in parallel with the optical axis of the light source, and rotates around the rotation axis to block illumination light incident from the light source by a light shielding portion or from an opening portion. Between the rotary shutter that emits light toward the light guide, and between the light source and the light guide, the central axis is arranged so as to coincide with the optical axis of the light source. Then, a shutter that blocks the progress of incident light, and a controller that controls the operation of the shutter and the imaging means,
The imaging means is driven by either interlace driving or progressive driving under the control of the controller,
When the imaging unit is driven in an interlaced manner, for each emission period in which illumination light is emitted from the opening, the imaging unit acquires an image of the observation site for one field as an electric charge, and follows the emission period. During the light blocking period in which the illumination light from the light source is blocked by the light blocking unit, the pixel data adjacent to the top and bottom of the charge accumulated in the imaging unit is added and transferred and stored in the image data storage unit,
When the imaging unit is progressively driven, the imaging unit acquires an image of the observation site for two fields as a charge in the light emission period in which illumination light is emitted from the opening, and the light emission period follows the light emission period. Through the light shielding period in which the illumination light from the light source is blocked by the light shielding unit, the next light emission period in which the illumination light is blocked by the shutter, the light shielding period following the light emission period, and the light emission period following the light emission period, An electronic endoscope characterized in that the accumulated electric charge is transferred and accumulated in the image data accumulation means.

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