ENDOSCOPE SYSTEM

An endoscope system is provided with an insertion portion, a direct-view observation window, a side-view observation window, a video processor, an image processing section configured to remove, overlapping regions between the first image and the plurality of second images and match lengths of sides of the plurality of second images to a length of a side of the first image, and a region of interest detection section configured to detect a region of interest from the plurality of second images. The image processing section performs image processing of canceling the processing of increasing the width of the image region as the distance from the region adjacent to the first image increases for only the second image from which the region of interest is detected among the plurality of second images according to a result of the detection conducted by the region of interest detection section.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an endoscope system, and more particularly, to an endoscope system capable of observing a direct-view direction and a side-view direction simultaneously.

2. Description of the Related Art

Endoscope systems provided with an endoscope that picks up an image of an object inside a subject and an image processing apparatus that generates an observation image of the object whose image is picked up by the endoscope are widely used in a medical field, an industrial field and the like.

For example, Japanese Patent Publication No. 3337682 discloses an endoscope system provided with an endoscope including a direct-view observation lens configured to acquire a direct-view visual field image provided on a distal end surface of a distal end portion of an insertion portion and a plurality of side-view observation lenses configured to acquire side-view visual field images provided in a circumferential direction of the distal end portion.

This endoscope is provided with image pickup devices at image forming positions of the direct-view observation lens and the plurality of side-view observation lenses respectively and a direct-view visual field image and a plurality of side-view visual field images are picked up by the respective image pickup devices. The direct-view visual field image is arranged at a center and the plurality of side-view visual field images are arranged on both sides of the direct-view visual field image and displayed on a monitor.

SUMMARY OF THE INVENTION

An endoscope system according to an aspect of the present invention is provided with an insertion portion configured to be inserted into an object, a first object image acquisition section provided in the insertion portion and configured to acquire a first object image from a first region of the object, a second object image acquisition section provided in the insertion portion and configured to acquire a plurality of second object images from a second region of the object which is at least partially different from the first region, an image signal generation section configured to generate a first image signal from the first object image and generate a plurality of second image signals from the plurality of second object images, an image processing section configured to arrange the plurality of second images so as to be adjacent to the first image, remove, when performing image processing so that widths of image regions of the plurality of second images increase in a fan-shape as a distance from a region adjacent to the first image increases in a positional relationship with the first image and displaying the images on a display section configured to display images, overlapping regions between the first image and the plurality of second images and match lengths of sides of the plurality of second images to a length of a side of the first image, and a region of interest detection section configured to detect a region of interest from the plurality of second images, in which the image processing section performs image processing of canceling the processing of increasing the width of the image region as the distance from the region adjacent to the first image increases for only the second image from which the region of interest is detected among the plurality of second images according to a result of the detection conducted by the region of interest detection section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

First Embodiment

First, a configuration of an endoscope system according to a first embodiment will be described usingFIG. 1toFIG. 3.FIG. 1is a diagram illustrating a configuration of the endoscope system according to the first embodiment,FIG. 2is a perspective view illustrating a configuration of a distal end portion of an insertion portion of an endoscope andFIG. 3is a diagram illustrating a configuration of main parts according to the first embodiment.

As shown inFIG. 1, an endoscope system1includes an endoscope2configured to pick up an image of an observation object and output an image pickup signal, a light source apparatus31configured to supply illuminating light to illuminate the observation object, a video processor32configured to possess a function as an image signal generation section that generates and outputs a video signal (image signal) corresponding to the image pickup signal, and a monitor35configured to display an observation image corresponding to the video signal (image signal).

The endoscope2is constructed of an operation portion3configured to be grasped by an operator to perform operation, an elongated insertion portion4formed on a distal end side of the operation portion3and inserted into a body cavity or the like, and a universal cord5, one end of which is provided so as to extend from a side part of the operation portion3.

The endoscope2according to the present embodiment is a wide-angle endoscope configured to display a plurality of visual field images and be capable of observing a visual field of 180 degrees or more and preventing overlooking of a lesion in a place difficult to detect only through observation in a direct-view direction such as the back of folds and a boundary of organs inside the body cavity, an interior of the large intestine in particular. When the insertion portion4of the endoscope2is inserted into the large intestine, operation such as temporary fixing by twisting, reciprocal motion of the insertion portion2and hooking of the intestinal wall is generated as in the case of a normal large intestine endoscope.

The insertion portion4is constructed of a rigid distal end portion6provided closest to the distal end side, a freely bendable bending portion7provided at a rear end of the distal end portion6, and a long and flexible tube portion8provided at a rear end of the bending portion7. Furthermore, the bending portion7performs bending operation corresponding to operation of a bending operation lever9provided at the operation portion3.

On the other hand, as shown inFIG. 2, a direct-view observation window11aconfigured to observe a direct-view direction (first direction) including a forward direction substantially parallel to a longitudinal direction of the insertion portion4, that is, a first region of an object, is disposed on a distal end surface of the distal end portion6of the endoscope2, and a plurality of side-view observation windows11b,11c,11dand11econfigured to observe a side-view direction (second direction) including a direction crossing the longitudinal direction of the insertion portion4which is at least partially different from the direct-view direction (first direction), that is, a second region of the object are disposed on a side face of the distal end portion6of the endoscope2. These side-view observation windows11bto11eare arranged in a circumferential direction of the distal end portion6at a uniform interval, for example, an interval of 90 degrees. Note that the side-view observation windows11bto11earranged in the circumferential direction of the distal end portion6at a uniform interval are not limited to the four side-view observation windows, but a configuration may be adopted in which one or more side-view observation windows are arranged as a left and right pair (two), for example.

A direct-view illuminating window12aconfigured to emit illuminating light over a range of the direct-view visual field of the direct-view observation window11ais disposed on the distal end surface of the distal end portion6of the endoscope2at a position adjacent to the direct-view observation window11a. Furthermore, side-view illuminating windows12bto12econfigured to emit illuminating light over ranges of the side-view visual fields of the side-view observation windows11bto11eare arranged on a side face of the distal end portion6of the endoscope2at positions adjacent to the side-view observation windows11bto11erespectively.

A distal end opening13configured to communicate with a treatment instrument channel, which is not shown, formed of a tube or the like and disposed in the insertion portion4and cause (a distal end portion of) a treatment instrument inserted through the treatment instrument channel to protrude, and a direct-view observation window nozzle portion14configured to eject a gas or liquid to clean the direct-view observation window11aare provided on the distal end surface of the distal end portion6of the endoscope2. Furthermore, side-view observation window nozzle portions, which are not shown, configured to eject a gas or liquid to clean the side-view observation windows11bto11eare provided on the side face of the distal end portion6of the endoscope2adjacent to the side-view observation windows11bto11erespectively.

A gas/liquid feeding operation button24athat can instruct operation of ejecting a gas or liquid to clean the direct-view observation window11afrom the direct-view observation window nozzle portion14and a gas/liquid feeding operation button24bthat can instruct operation of ejecting a gas or liquid to clean the side-view observation windows11bto11efrom a side-view observation window nozzle portion, which is not shown, are provided at the operation portion3as shown inFIG. 2, and it is possible to switch between gas feeding and liquid feeding by pressing the gas/liquid feeding operation buttons24aand24b. In the present embodiment, a plurality of gas/liquid feeding operation buttons are provided so as to correspond to the respective nozzle portions, but the present embodiment may be configured so that a gas or liquid is ejected from both the direct-view observation window nozzle portion14and the side-view observation window nozzle portions which are not shown, for example, through operation of one gas/liquid feeding operation button.

A plurality of scope switches25are provided at a top of the operation portion3and configured such that functions specific to the respective switches can be assigned thereto so as to output signals corresponding to ON, OFF or the like of various descriptions available to the endoscope2. More specifically, the scope switches25can be assigned functions of outputting signals corresponding to the starting and stopping of forward water feeding, execution and releasing of freezing, announcement of an operating condition of a treatment instrument or the like as functions specific to the respective switches.

Note that at least one of the functions of the gas/liquid feeding operation buttons24aand24bmay be assigned to one of the scope switches25in the present embodiment.

Furthermore, a suction operation button26configured to be able to instruct a suction unit or the like, which is not shown, to suction and collect mucus or the like in the body cavity from the distal end opening13is disposed at the operation portion3.

The mucus or the like inside the body cavity suctioned in response to the operation of the suction unit or the like, which is not shown, is passed through the distal end opening13, the treatment instrument channel, which is not shown, in the insertion portion4and a treatment instrument insertion opening27provided in the vicinity of a front end of the operation portion3, and then collected into a suction bottle or the like of the suction unit, which is not shown.

The treatment instrument insertion opening27communicates with the treatment instrument channel, which is not shown, in the insertion portion4and is formed as an opening through which a treatment instrument, which is not shown, can be inserted. That is, the operator inserts the treatment instrument from the treatment instrument insertion opening27, causes the distal end side of the treatment instrument to protrude from the distal end opening13, and can thereby perform treatment using the treatment instrument.

On the other hand, as shown inFIG. 1, a connector29which is connectable to the light source apparatus31is provided at the other end of the universal cord5.

A pipe sleeve (not shown) which is a connection end of a fluid conduit and a light guide pipe sleeve (not shown) which is a supply end of illuminating light are provided at a distal end portion of the connector29. Furthermore, an electric contact point (not shown) to which one end of a connection cable33is connectable is provided on a side face of the connector29. Moreover, a connector to electrically connect the endoscope2to the video processor32is provided at the other end of the connection cable33.

A plurality of signal lines to transmit various electric signals and a light guide to transmit illuminating light supplied from the light source apparatus31are bundled and incorporated in the universal cord5.

The light guide incorporated from the insertion portion4to the universal cord5is configured such that an end thereof on the light-emitting side is branched into at least five directions in the vicinity of the insertion portion4and the respective light-emitting end faces are arranged at the direct-view illuminating window12aand the side-view illuminating windows12bto12e. The light guide is configured such that an end thereof on the light incidence side is disposed at the light guide pipe sleeve of the connector29.

Note that the light-emitting portions arranged at the direct-view illuminating window12aand the side-view illuminating windows12bto12emay be light-emitting devices such as light-emitting diodes (LEDs) instead of light guides.

The video processor32outputs drive signals to drive a plurality of image pickup devices provided at the distal end portion6of the endoscope2. The video processor32functions as an image signal generation section configured to apply signal processing to image pickup signals outputted from the plurality of image pickup devices, generate video signals (image signals) and output the video signals to the monitor35.

Although details will be described later, the processor32arranges the direct-view visual field image acquired by the direct-view observation window11aat the center and arranges the four side-view visual field images acquired by the side-view observation windows11bto11eabove and below, and to the left and right of the direct-view visual field image, applies predetermined image processing (deformation processing) to the direct-view visual field image and the four side-view visual field images and outputs the images to the monitor35. That is, the processor32performs treatment so as to arrange the direct-view visual field image acquired by the direct-view observation window11aand the side-view visual field images acquired by the side-view observation windows11bto11eat positions adjacent to each other and generates a video signal.

Peripheral apparatuses such as the light source apparatus31, the video processor32and the monitor35are arranged on a rack36together with a keyboard34configured to input patient information or the like.

As shown inFIG. 3, the direct-view observation window11athat constitutes a first object image acquisition section acquires a first object image from a direct-view direction (first direction) including a forward direction substantially parallel to the longitudinal direction of the insertion portion4, that is, from the first region of the object. An image pickup device15ais disposed at an image forming position of the direct-view observation window11aand an objective optical system, which is not shown, configured to photoelectrically convert the object image acquired by the direct-view observation window11a. Note that the insertion portion4shown inFIG. 3is a cross-sectional view along a line III-III inFIG. 2.

On the other hand, the side-view observation windows that constitute a second object image acquisition section (at least one or more side-view observation windows of the side-view observation windows11bto11e) acquire second object images from a side-view direction (second direction) including a direction crossing the longitudinal direction of the insertion portion4which is at least partially different from the direct-view direction (first direction), that is, the second region of the object.

Note that boundary regions between the first object image and the second object images may overlap or may not overlap with each other, and when the above-described boundary regions overlap, the first object image acquisition section and the second object image acquisition section may acquire overlapping object images.

An image pickup device15bis disposed at an image forming position of the side-view observation window11band an objective optical system, which is not shown, configured to photoelectrically convert an object image acquired by the side-view observation window11b.

Similarly, an image pickup device15dis disposed at an image forming position of the side-view observation window11dand an objective optical system, which is not shown, configured to photoelectrically convert an object image acquired by the side-view observation window11d. Note that an image pickup device, which is not shown, (hereinafter referred to as “image pickup device15c”) is disposed at an image forming position of the side-view observation window11cand the objective optical system which is not shown and an image pickup device, which is not shown, (hereinafter referred to as “image pickup device15e”) is disposed at an image forming position of the side-view observation window11eand an objective optical system, which is not shown. The object images acquired by the image pickup devices15cand15ethrough the side-view observation windows11cand11eare photoelectrically converted.

The image pickup devices15ato15eare respectively electrically connected to an image processing section32aand the direct-view visual field image picked up by the image pickup device15aand the side-view visual field images respectively picked up by the image pickup devices15bto15eare outputted to the image processing section32a.

The image processing section32aarranges the direct-view visual field image acquired by the direct-view observation window11aat the center, arranges the four side-view visual field images acquired by the side-view observation windows11bto11eabove and below, and to the left and right of the direct-view visual field image, applies predetermined image processing to the direct-view visual field image and the four side-view visual field images and outputs the images to an image output section32b.

The image output section32bgenerates a signal to be displayed on the monitor35from the image signal generated by the image processing section32aand outputs the signal to the monitor35.

Next, image processing by the image processing section32awill be described usingFIG. 4AandFIG. 4B.

FIG. 4AandFIG. 4Bare diagrams illustrating an example of an observation image displayed on the monitor through the image processing by the image processing section32a.

The image processing section32aacquires the direct-view visual field image16aacquired by the direct-view observation window11aand the side-view visual field images16bto16eacquired by the side-view observation windows11bto11e. The image processing section32aarranges the direct-view visual field image16aat the center and arranges the side-view visual field images16bto16eadjacent to the direct-view visual field image16ain the vertical and horizontal directions as shown inFIG. 4A. More specifically, the image processing section32aarranges the side-view visual field image16bon the left side of the direct-view visual field image16a, arranges the side-view visual field image16cbelow the direct-view visual field image16a, arranges the side-view visual field image16don the right side of the direct-view visual field image16aand arranges the side-view visual field image16eabove the direct-view visual field image16a.

The image processing section32athen applies predetermined image processing to the direct-view visual field image16aand the side-view visual field images16bto16b. More specifically, the image processing section32aapplies circular electronic masking to the direct-view visual field image16aand generates a substantially circular direct-view visual field image17a.

Furthermore, the image processing section32aapplies deformation processing (distortion) to the side-view visual field images16bto16earranged above and below, and to the left and right so that the images are expanded as their distances from the center increase, that is, the widths of the image regions increase as their distances from the regions adjacent to the direct-view visual field image16aincrease in a positional relationship with the direct-view visual field image16aand generates substantially fan-shaped side-view visual field images17bto17e. The substantially circular direct-view visual field image17aand the fan-shaped side-view visual field images17bto17egenerated by the image processing section32aare displayed on the monitor35via the image output section32b.

Thus, the image processing section32aperforms image processing in a width expansion mode which is an image processing mode in which the image processing section32agenerates a first image signal from a first object image, generates a second image signal from a second object image and processes the second image signal so that the width of the second object image increases as the distance from the center of the first object image increases.

Note that when a plurality of images are displayed on the monitor35, the side-view visual field images17bto16eare configured to be arranged above and below, and to the left and right of the direct-view visual field image17a, but without being limited to this, the direct-view visual field image and the side-view visual field images only need to neighbor each other, and a configuration may be adopted in which the side-view visual field image is disposed either to the left or right of the direct-view visual field image17a.

In the present embodiment, a plurality of images are displayed on the monitor35, but the present embodiment is not limited to this. As shown inFIG. 4B, such a configuration may be adopted in which a plurality of, for example, five monitors35are arranged adjacent to each other, the direct-view visual field image17ais displayed on the central monitor35and the side-view visual field images17bto17eare displayed on the upper, lower, left and right monitors35respectively.

Note that specific shapes of the side-view visual field images17bto17egenerated by the image processing section32amay be as shown inFIG. 5AandFIG. 5B.FIG. 5AandFIG. 5Bare diagrams for describing the specific shapes of the side-view visual field images17bto17e.

As shown inFIG. 5A, the image processing section32amay generate fan-shaped side-view visual field images17bto17econcentric to the direct-view visual field image17aand having an internal angle of substantially 90 degrees. Furthermore, the image processing section32amay generate fan-shaped side-view visual field images17bto17ewhere a distortion (curvature of field) level L1of the side-view visual field images17bto17ebecomes substantially equal to a distortion level L2of the peripheral part of the direct-view visual field image17aas shown inFIG. 5B.

The direct-view visual field image17aoriginally contains a certain degree of distortion in its peripheral part for reasons related to the optical system. For this reason, the image processing section32aperforms image processing so that the side-view visual field images17bto17ebecome distorted images in accordance with the peripheral part of the direct-view visual field image17a(so as to obtain radial perspective). In that case, the image processing section32amay set slightly wider visual fields for the side-view visual field images17bto17eso as to overlap the direct-view visual field image17aextracted using electronic masking so as to complement the shortfall (electronically masked portion) of the direct-view visual field image17awhen images are superimposed one on another.

In this way, the endoscope system1acquires the direct-view visual field image16athrough the direct-view observation window11a, acquires the side-view visual field images16bto16ethrough the side-view observation windows11bto11e, arranges the direct-view visual field image16aat the center and arranges the side-view visual field images16bto16eabove and below, and to the left and right of the direct-view visual field image16a. The endoscope system1generates the substantially circular direct-view visual field image17aresulting from applying circular electronical masking to the direct-view visual field image16aand the fan-shaped side-view visual field images17bto17eresulting from applying deformation processing to the side-view visual field images16bto16eso that their widths increase as the respective distances from the regions adjacent to the direct-view visual field image16aincrease.

As a result, since the direct-view visual field image17aand the side-view visual field images17bto17edisplayed on the monitor35can produce perspective, it is possible to improve viewability in a cylindrical lumen such as the large intestine and improve operability.

Thus, according to the endoscope system of the present embodiment, it is possible to improve viewability and improve operability of the endoscope when the endoscope is inserted into the lumen.

Second Embodiment

Next, a second embodiment will be described.

FIG. 6is a perspective view illustrating a configuration of a distal end portion of an insertion portion of an endoscope according to a second embodiment andFIG. 7is a diagram illustrating a configuration of main parts according to the second embodiment. Note that inFIG. 6andFIG. 7, components similar to those inFIG. 2andFIG. 3are assigned the same reference numerals and description thereof will be omitted.

As shown inFIG. 6, a side face of the distal end portion6aof the endoscope2according to the present embodiment is configured by removing the side-view observation windows11cand11eand the side-view illuminating windows12cand12efrom the side face of the distal end portion6inFIG. 2. That is, the endoscope2of the present embodiment acquires the direct-view visual field image16athrough the direct-view observation window11aand acquires the two side-view visual field images16band16dthrough the side-view observation windows11band11d.

As shown inFIG. 7, the video processor32according to the present embodiment is constructed using an image processing section32a1instead of the image processing section32ainFIG. 3. The image processing section32alarranges the direct-view visual field image16aacquired by the direct-view observation window11aat the center, arranges the side-view visual field images16band16dacquired by the side-view observation windows11band11dside by side to the left and right of the direct-view visual field image16a, and applies predetermined image processing (deformation processing) to the side-view visual field images16band16d.

The image processing section32a1is provided with a region of interest detection section32c. The region of interest detection section32cdetects a predetermined region of interest such as a lesion in the side-view visual field image subjected to deformation processing by detecting, for example, a color tone change. When a lesion is detected by the region of interest detection section32c, the image processing section32a1cancels the deformation processing on the side-view visual field image subjected to the deformation processing in which the lesion is reflected, and displays an enlarged image thereof. Note that when there is any part whose color tone is different from other parts in the side-view visual field image (when a lesion is detected), that part may be extracted and an enlarged image thereof may be displayed.

Next, image processing by the image processing section32a1will be described usingFIG. 8AtoFIG. 8C.

FIG. 8AtoFIG. 8Care diagrams illustrating an example of an observation image displayed on a monitor through image processing by the image processing section32al.

The image processing section32a1acquires the direct-view visual field image16aacquired by the direct-view observation window11aand the side-view visual field images16band16dacquired by the side-view observation windows11band11d. The image processing section32a1arranges the direct-view visual field image16aat the center and arranges the side-view visual field images16band16dside by side to the left and right of the direct-view visual field image16a.

The image processing section32a1applies deformation processing to the side-view visual field images16band16dso that the side-view visual field images16band16dare expanded as their distances from the respective regions adjacent to the direct-view visual field image16increase to thereby generate side-view visual field images18band18drespectively. More specifically, trapezoidal side-view visual field images18band18dare generated, whose lengths of sides close to the direct-view visual field image16aare substantially identical to the length of the side of the direct-view visual field image16aand whose lengths of sides far from the direct-view visual field image16aare longer than the length of the sides closer to the direct-view visual field image16a. The direct-view visual field image16a, and the side-view visual field images18band18dsubjected to the deformation processing are displayed on the monitor35via the image output section32b.

When the region of interest detection section32cdetects a lesion19in, for example, the side-view visual field image18d, the image processing section32alcauses the monitor35to display a side-view visual field image18dlresulting from cancelling the deformation processing of the side-view visual field image18din which the lesion is reflected. Furthermore, the image processing section32a1generates a side-view visual field image18d2which is an enlarged image of the side-view visual field image18d1whose deformation processing is canceled and causes the monitor35to display this side-view visual field image18d2.

Thus, the endoscope system1generates the side-view visual field images18band18dsubjected to deformation processing whereby the side-view visual field images18band18dare expanded as their distances from the center increase, and can thereby improve viewability and improve operability of the endoscope when the endoscope is inserted into the lumen as in the case of the first embodiment. Upon detecting the lesion19in the side-view visual field image18bor18d, the endoscope system1cancels the deformation processing on the side-view visual field image18bor18din which the lesion19is detected, and enable thereby observation of the lesion19in an image free of distortion.

Note that as shown inFIG. 8B, the direct-view visual field image16aand the side-view visual field images16band16d(18band18d) may be displayed on the monitor35in plurality respectively. Alternatively, as shown inFIG. 8C, if there is an overlapping part between two neighboring image signals, the images may be displayed by deleting the overlapping part from the image signals.

Next, a modification of the second embodiment will be described.

FIG. 9is a perspective view illustrating a configuration of a distal end portion of an insertion portion of an endoscope according to a modification,FIG. 10is a front view illustrating a configuration of the distal end portion of the insertion portion of the endoscope according to the modification andFIG. 11is a diagram illustrating a configuration of main parts according to the modification.

As shown inFIG. 9, a columnar cylindrical portion40is formed at the distal end portion6bof the insertion portion4, protruding from a position deviated upward from the center of the distal end surface of the distal end portion6b.

An objective optical system, which is not shown and configured to provide both a direct-view and a side-view, is provided at a distal end portion of the cylindrical portion40. The distal end portion of the cylindrical portion40is configured to include a direct-view observation window42that constitutes a first object image acquisition section disposed at a position corresponding to a direct-view direction of the objective optical system which is not shown, and a side-view observation window43that constitutes a second object image acquisition section disposed at a position corresponding to a side-view direction of the objective optical system, which is not shown. Furthermore, a side-view illumination section44configured to emit light for illuminating the side-view direction is formed in the vicinity of a proximal end of the cylindrical portion40.

The direct-view observation window42captures return light (reflected light) from an observation object incident from a first region including a forward direction of the insertion portion4substantially parallel to the longitudinal direction of the insertion portion4within the direct-view visual field as a direct-view object image, and thereby acquires a direct-view visual field image.

The side-view observation window43captures return light (reflected light) from the observation object incident from a circumferential direction of the columnar cylindrical portion40within the side-view visual field, and is provided with a side-view mirror lens45to thereby allow a side-view visual field image to be acquired.

Such an image is realized using a two-time reflection optical system in which the return light is reflected twice by the side-view mirror lens45, but such an image may be formed by causing the return light to be reflected once by a one-time reflection optical system, subjecting the image to image processing by the video processor32and matching the orientation of the side-view visual field image to that of the direct-view visual field image.

Note that (an image pickup surface of) an image pickup device60shown inFIG. 11is assumed to be disposed at an image forming position of the objective optical system, which is not shown, so that an image of an observation object within a visual field of the direct-view observation window42is formed at a central part as a circular direct-view visual field image and an image of an observation object within a visual field of the side-view observation window43is formed on an outer circumferential portion of the direct-view visual field image as a ring-shaped side-view visual field image.

A direct-view illuminating window46disposed at a position adjacent to the cylindrical portion40and configured to emit illuminating light within a range of the direct-view visual field of the direct-view observation window42and a distal end opening47configured to communicate with a treatment instrument channel, which is formed of a tube or the like disposed in the insertion portion4and which is not shown, and be enabled to cause (a distal end portion of) the treatment instrument inserted through a treatment instrument channel to protrude therefrom are provided on the distal end surface of the distal end portion6b.

The distal end portion6bof the insertion portion4includes a supporting portion48provided so as to protrude from the distal end surface of the distal end portion6band this supporting portion48is located below and adjacent to the cylindrical portion40.

The supporting portion48is configured to be able to support (or hold) each protruding member disposed so as to protrude from the distal end surface of the distal end portion6b. More specifically, the supporting portion48is configured to be able to support (or hold) a direct-view observation window nozzle portion49configured to eject a gas or liquid to clean the direct-view observation window42, a direct-view illuminating window51configured to emit light for illuminating a direct-view direction, and a side-view observation window nozzle portion52configured to eject a gas or liquid to clean the side-view observation window43, as each aforementioned protruding member.

On the other hand, the supporting portion48includes a shielding portion48awhich is an optical shielding member configured to prevent acquisition of a side-view visual field image that may include any one of the respective protruding members when each aforementioned protruding member which is an object different from original observation objects appears within the side-view visual field. That is, by providing the supporting portion48with the shielding portion48a, it is possible to obtain a side-view visual field image that includes none of the direct-view observation window nozzle portion49, the direct-view illuminating window51or the side-view observation window nozzle portion52.

As shown inFIG. 9andFIG. 10, the side-view observation window nozzle portion52is provided at two locations of the supporting portion48and is disposed such that the distal end thereof protrudes from the side face of the supporting portion48.

The video processor32outputs a drive signal to drive the image pickup device60provided at the distal end portion6bof the endoscope2. The video processor32applies signal processing to an image pickup signal outputted from the image pickup device60, thereby generates a video signal and outputs the video signal to the monitor35. Thus, the monitor35displays an observation image including a circular direct-view visual field image and a ring-shaped side-view visual field image arranged adjacent to the direct-view visual field image and around an outer circumference of the direct-view direction image. Note that the portion optically shielded by the shielding portion48aof the supporting portion48will not be considered in observation images shown in the present embodiment and subsequent embodiments.

It is not possible to obtain perspective or a three-dimensional effect only by arranging one or more side-view visual field images next to the direct-view visual field image and it is difficult to recognize the image obtained as an observation image of the luminal interior without any unnatural feeling.

In contrast, the method of displaying the direct-view visual field image and the side-view visual field images of the modification is set to provide an optical structure whereby the screen spreads radially from the center toward the periphery (such an optical characteristic is automatically set in the case of a ring-shaped lens), and perspective and a three-dimensional effect can therefore be obtained relatively easily.

Next, image processing by the image processing section32a1will be described usingFIG. 12.

FIG. 12is a diagram illustrating an example of an observation image displayed on a monitor through image processing by the image processing section32a1.

As shown inFIG. 12, the image processing section32a1acquires a circular direct-view visual field image61and a ring-shaped side-view visual field image62around an outer circumference of the direct-view visual field image61. Moreover, the image processing section32a1divides the side-view visual field image62into four upper, lower, left and right regions62a,62b,62cand62d. Note that the number of divided regions is not limited to four, but may be three or less or five or more.

When the region of interest detection section32cdetects, for example, a lesion19, the image processing section32a1applies only to, for example, the region62bof the side-view visual field image62in which the lesion19is included, distortion elimination processing that cancels a state in which the width of the image region increases as the distance from the region adjacent to the direct-view visual field image increases, generates an enlarged image62b1and displays the enlarged image62b1on the monitor35as a switchover mode. As a result, the endoscope system1of the modification cancels the deformation processing on the region in which the lesion19is detected, and can thereby observe the lesion19in a distortion-free image as in the case of the second embodiment.

Third Embodiment

Next, a third embodiment will be described.

FIG. 13is a diagram illustrating a configuration of main parts according to the third embodiment. Note that inFIG. 13, components similar to those inFIG. 7are assigned the same reference numerals and description thereof will be omitted. The configuration of the distal end portion of the insertion portion4is similar to that of the distal end portion6ainFIG. 6.

As shown inFIG. 13, the video processor32of the present embodiment is configured using an image processing section32a2instead of the image processing section32a1inFIG. 7. The image processing section32a2arranges the direct-view visual field image16aacquired by the direct-view observation window11aat the center, arranges the side-view visual field images16band16dacquired by the side-view observation windows11band11dside by side to the left and right of the direct-view visual field image16a, and applies predetermined image processing (deformation processing) to the side-view visual field images16band16d.

The image processing section32a1is provided with a distortion correction processing section32dconfigured to correct distortion in horizontal and vertical directions. The distortion correction processing section32dapplies distortion elimination processing to the direct-view visual field image16aand the two side-view visual field images subjected to the deformation processing so as to clear distortion to zero. The direct-view visual field image and the two side-view visual field images subjected to the distortion elimination processing are displayed on the monitor35via the image output section32b.

Next, the image processing by the image processing section32a2will be described usingFIG. 14.

FIG. 14is a diagram illustrating an example of an observation image displayed on the monitor through the image processing by the image processing section32a2.

Distortion generally exists in the acquired direct-view visual field image16aand side-view visual field images16band16d, and the distortion direction differs in the vicinity of the boundary between the direct-view visual field image16aand the side-view visual field images16band16d. For this reason, when an object (e.g., lesion19) moves between the respective images, even the identical object differs in its appearance and behavior, and it is therefore difficult to recognize that it is the identical object.

Thus, the distortion correction processing section32dgenerates a direct-view visual field image20aby applying to the direct-view visual field image16a, distortion elimination processing that sets distortion to zero. Furthermore, the distortion correction processing section32dgenerates side-view visual field images20band20dby applying distortion elimination processing that sets distortion to zero to the side-view visual field images subjected to deformation processing by the image processing section32a2so that the side-view visual field images16band16dare expanded as the distances from the center increase.

The direct-view visual field image20a, and the side-view visual field images20band20dsubjected to the distortion elimination processing are displayed on the monitor35via an image output section32b. Thus, for example, even when the object (lesion19) of the side-view visual field image20dmoves to the direct-view visual field image20a, its appearance and behavior become substantially identical. As a result, the endoscope system of the present embodiment exerts an effect of improving viewability when the object (lesion19) moves from the side-view visual field image20bor20dto the direct-view visual field image20a(or from the direct-view visual field image20ato the side-view visual field image20bor20d) in addition to the effect of the first embodiment.

Of the above-described embodiments, according to the embodiments in which a plurality of visual field images are arranged side by side and displayed, the mechanism for implementing the function of illuminating and observing the lateral direction is incorporated in the distal end portion6of the insertion portion4together with the mechanism for implementing the function of illuminating and observing the forward direction, but the mechanism for implementing the function of illuminating and observing the lateral direction may be a separate body detachable from the insertion portion4.

FIG. 15is a perspective view of the distal end portion6of the insertion portion4to which a side observation unit is attached. The distal end portion6of the insertion portion4includes a forward visual field unit100. A side visual field unit110is configured to be detachable from the forward visual field unit100by means of a clip portion111.

The side visual field unit110includes two observation windows112to acquire images in left and right directions and two illuminating windows113to illuminate the left and right directions.

The video processor32or the like may be configured to turn on or off the respective illuminating windows113of the side visual field unit110in accordance with a frame rate of the forward visual field so as to be able to acquire and display an observation image as shown in the aforementioned embodiments.

The present invention is not limited to the aforementioned embodiments, but can be changed, modified or the like in various ways without departing from the spirit and scope of the present invention.