JP2009028462A - Electronic endoscope device - Google Patents

Abstract

An endoscope is made easier to use by widening the field of view of the electronic endoscope. In particular, the rear visual field of the insertion portion can be observed.
[Solution]
An imaging surface of one solid-state imaging device is divided into two imaging regions, and an objective lens system having a front visual field direction with respect to the insertion axis of the insertion portion and an objective having a rear visual field direction are divided into two imaging regions. It is characterized by an electronic endoscope apparatus having a wide range of observation fields in the front and rear by arranging and arranging a lens system to capture and display images in two directions.
[Selection] Figure 4

Description

  The present invention divides an imaging surface of one solid-state imaging device into two imaging regions, and an objective lens system having a front field of view with respect to the insertion direction of the insertion portion and a rear field of view in the two divided imaging regions The objective lens system is arranged so that images in two directions, the front field of view and the back field of view, are read out as video signals, and simultaneously or separately displayed on the video display device as a video, thereby providing a wide range of front and rear observation fields. The present invention relates to an electronic endoscope apparatus.

  An electronic endoscope apparatus for observing the inside of a device as a subject or inside a body cavity is sometimes referred to as an insertion portion that is inserted into the specimen and an operation portion (a gripping portion) provided at the other end of the insertion portion. An imaging unit including a solid-state imaging device typified by a CMOS sensor or a CCD sensor and an objective lens system is incorporated at the distal end of the insertion portion, and a video signal from the imaging unit is predetermined by a signal processing circuit. In general, signal processing is performed, and an image is displayed on an image display device provided outside.

  FIG. 1 shows a basic configuration of an electronic endoscope apparatus. In the figure, 1 is an electronic endoscope (main body), 2 is a camera control unit (hereinafter referred to as CCU) having a signal processing circuit, 3 is a light source device for illumination, and 4 is a monitor as video display means. . In this specification, an optical image formed by the objective lens system is represented as an image, and is used separately from an image formed from a video signal.

  The endoscope is composed of an insertion section 6 to be inserted into the specimen and an operation section 5 for holding and operating the endoscope by hand. At the distal end of the endoscope is an objective lens system 7, a CCD sensor, a CMOS sensor, etc. The solid-state imaging device 8 represented by the above is incorporated as an imaging unit, and a light guide 9 for illuminating the field of view of the objective lens is incorporated as an illuminating means on the end face of the tip. A video signal from the solid-state imaging device 8 is connected to the CCU 2 by a cable 10, and the other end surface of the light guide 9 is connected to the light source device 3. It should be noted that the mechanism of the operation unit that is not directly related to the present invention is not shown.

  Conventionally, most CCUs that process video signals from the image pickup unit are provided outside the endoscope, and a configuration in which a part of a preamplifier circuit or the like is incorporated in the operation unit is generally used. In recent years, signal processing circuit devices have been miniaturized, and those in which a signal processing circuit is incorporated in an operation unit or an imaging unit at the tip have been put into practical use. As small high-efficiency white diodes are put into practical use, it has become possible to place white diodes at the distal end of endoscopes instead of light guides. In this case, the light source unit is unnecessary, and the power source of the white light emitting diode can be supplied from the CCU.

  In this way, there are many types of electronic endoscopes that incorporate an imaging unit including a solid-state imaging device and an objective lens system at the distal end of the insertion section. For the purpose of observing the inside of an industrial device and the inside of a body cavity, However, in the conventional electronic endoscope, an imaging unit including one solid-state imaging device and one objective lens system is incorporated in the distal end portion. Many have a visual field of direction.

  However, since the range of observation is limited in an electronic endoscope having separate visual fields in the direct viewing and side viewing directions, there is a demand from users who use an electronic endoscope having a plurality of visual fields simultaneously.

  In response to such a demand, as an electronic endoscope having a plurality of different viewing directions, Japanese Utility Model Publication No. 4-40183 discloses a plurality of objective lens systems having a field of view in a direct view and a side view direction in one solid-state imaging device. Proposals are made individually.

  Japanese Patent Application Laid-Open No. 9-313435 also proposes an electronic endoscope apparatus that can be observed as an image in which direct viewing and side viewing directions are simultaneously continuous.

  In an electronic endoscope, the insertion part is generally composed of a soft member, and the distal end of the insertion part generally has a structure having a bending part that can be bent from the operation part. These rigid endoscopes are also used in a wide range of fields because of their simple mechanical structure and easy price. In either case, since the visual field direction with respect to the insertion direction of the electronic endoscope is limited to the front or side, a portion that cannot be captured in the visual field occurs depending on the shape of the observation site of the specimen.

  A state in which the above-described visual field is limited will be described with reference to FIG. As shown in the figure, even in the case of an electronic endoscope having a front-view visual field 12 and a side-view visual field 13 with respect to the insertion direction 11 of the insertion portion 6, the space inside the observation object interior 15 is wider than the entrance 14. It is not possible to observe the hatched entrance periphery 16 for the specimen.

  As shown in FIG. 2B, the objective lens system of the imaging unit is arranged so that the front end portion of the electronic endoscope has a front-view visual field 12 and a rear visual field 17 with respect to the insertion direction 11 of the insertion portion 6. In the case of the arranged electronic endoscope, the hatched entrance peripheral portion 16 can be sufficiently observed even for a specimen having a larger space in the observation object interior 15 than the entrance 14.

The observation object having a larger space inside the observation objective than the entrance for inserting the electronic endoscope as shown in FIG. 2 is often a device, and such a joint is easily stressed and easily damaged. Therefore, it is important as an observation target. Even in the case of the human body, there are many fistula diseases from the vicinity of the anus to the rectum, and an electronic endoscope that can provide a rear visual field has a great effect.
Utility Model Public Notice No. 4-40183 JP 9-313435 A

  As an attempt to expand the field of view of an electronic endoscope, a wide-angle objective lens system having a viewing angle of about 120 degrees as the objective lens system, or a front-view visual field on the side of the insertion axis of the insertion unit It has also been proposed to dispose the objective lens system so as to obtain a side view field in one direction, and it is possible to cover a wide range. However, in either case, it was not possible to observe the back with respect to the insertion direction of the insertion portion. The present invention has been made paying attention to the above-described points, and an object thereof is to provide an electronic endoscope apparatus with good operability having a front visual field and a rear visual field with respect to the insertion direction of the insertion portion of the electronic endoscope. It is said.

  Furthermore, by arranging an objective lens system having a front field of view and an objective lens system having a rear field of view with respect to the insertion direction of the insertion portion on one solid-state imaging device, only one signal processing circuit is required. An object of the present invention is to provide an electronic endoscope that can be reduced in cost and can be used in a wide range.

  In order to achieve the above object, an invention according to claim 1 is an electronic endoscope apparatus in which an imaging unit including an objective lens system and a solid-state imaging device is arranged at the distal end of an insertion portion. One solid-state imaging device is arranged so as to be parallel to the insertion direction of the insertion portion, the imaging surface of the solid-state imaging device is divided into two to form a first imaging region and a second imaging region, A first objective lens system having a front field of view with respect to the insertion direction of the insertion portion of the endoscope is attached to the first imaging region via an optical member that converts the optical axis, and the second imaging region is provided to the second imaging region. An electronic endoscope apparatus having a structure in which a second objective lens system having a rear field of view with respect to the insertion direction of the insertion portion of the endoscope is provided via an optical member that converts an optical axis is characterized.

  More specifically, many conventional endoscope apparatuses have an imaging unit in which the objective lens system and the imaging surface of the solid-state imaging device have a right-angle positional relationship, but the visual field direction of the objective lens is set to the insertion direction of the endoscope insertion portion. In order to have a rear field of view, another image pickup unit is arranged and two signal processing circuits are required. As in the present invention, the solid-state imaging device is arranged so that the imaging surface of the solid-state imaging device is parallel to the insertion axis direction of the endoscope insertion portion, and an object is obtained via an optical member that converts the optical axis such as a prism. An objective lens system having a front visual field and a rear visual field can be mounted on the imaging surface of one solid-state image sensor by bending the optical axis of the lens system at a right angle on the imaging surface of the solid-state image sensor, and a signal processing circuit. Has the effect of using only one set.

  According to a second aspect of the present invention, an image formed on the first imaging area and the second imaging area of the solid-state imaging device is simultaneously read out as a video signal, subjected to signal processing, and written on the memory. By controlling the readout method, the image formed in the first imaging area and the image formed in the second imaging area on the screen of the display device can be selected and displayed simultaneously or individually as images. An electronic endoscope apparatus according to claim 1 is provided.

  More specifically, the video signal from the solid-state image sensor is first processed by the CPU, written on the memory provided in the CPU, and the method of reading the video signal from the memory is controlled, so that View field-of-view video (for example, video captured in the first imaging area) and rear-view video (for example, video captured in the second imaging area) side-by-side, or monitor either the front-view video or the rear-view video It can be displayed above.

  According to a third aspect of the present invention, there is provided a necessary range portion of an image formed by the first objective lens system in the first imaging region of the solid-state imaging device, and a second objective lens system formed in the second imaging region. A reading area control unit for a solid-state imaging device that separately reads a necessary range portion of an image to be read as a video signal, and separately displays an image in the first imaging area and an image in the second imaging area on the video display device. It is an object of the present invention to provide an endoscope apparatus according to claim 1.

  More specifically, various imaging states are conceivable even when a front visual field image and a rear visual field image are captured in a first imaging region and a second imaging region formed on one solid-state imaging device. Although detailed description will be given in the embodiments described later, the necessary range portion of the image formed by the objective lens system is limited to a part of the first imaging area and the second imaging area on the solid-state imaging device. By separately reading out the necessary range portion of the image as a video signal, the signal amount of the video signal in each imaging region can be limited, and the transmission of the video signal is facilitated.

  According to a fourth aspect of the present invention, the video signal read from the solid-state imaging device is subjected to predetermined signal processing, and then transmitted to a personal computer via a USB2 standard digital interface to display the video, and white light emission for illumination 4. The endoscope apparatus according to claim 3, wherein power of the diode is supplied from a USB2 terminal of a personal computer.

  More specifically, even when a solid-state imaging device equivalent to 1.3 million pixels is used, an image having a number of pixels equivalent to VGA (640 × 480 dots) is read out as a cutout video signal. Since a second video signal can be obtained, the cost can be reduced. In addition, if the video signal is 30 frames / second with VGA, a standard digital interface called USB2 can be used, and the video of the electronic endoscope can be directly read into a PC (personal computer). A system can also be constructed.

  In the electronic endoscope apparatus according to the present invention, the imaging unit incorporated at the distal end of the insertion portion has one objective lens optical system having a front field of view and one objective lens optical system having a rear field of view with respect to the insertion axis direction of the insertion portion. The signal processing circuit for video signals can be simplified by disposing it on the solid-state imaging device, and an electronic endoscope apparatus having a wide field of view that does not cost can be realized.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings used in the description of the embodiments, specific details such as mechanisms not directly related to the present invention are omitted so that the present invention can be easily understood and understood.

  FIG. 3 is a schematic configuration diagram of an endoscope apparatus showing an embodiment of the present invention. As in FIG. 1, 1 is an endoscope (main body), 2 is a CCU having a signal processing circuit, and 4 is a monitor as an image display device.

  The endoscope 1 is composed of an insertion portion 6 to be inserted into the specimen and an operation portion 5 for holding and operating the endoscope by hand. The distal end portion 18 of the insertion portion 6 is shown in detail in FIG.

  FIG. 4 shows the structure of the distal end portion 18 of the endoscope insertion portion 6 shown in FIG. 3, and is represented by an objective lens system 20 having a front field of view, an objective lens system 21 having a rear field of view, a CMOS sensor, and the like. One solid-state imaging device 22 is incorporated as an imaging unit, and white emitting diodes (LEDs) 27 and 28 for illuminating the viewing direction are incorporated as illumination means in the vicinity of the objective lens systems 20 and 21. A video signal from the solid-state imaging device 22 is connected to the CCU by a cable 10 via a signal processing circuit such as a preamplifier 29, and the power of the LED is supplied from the CCU.

  In the imaging unit having the front field of view and the rear field of view, the imaging surface of the solid-state imaging device 22 is arranged substantially in parallel with the insertion direction 11 of the insertion unit 6, and the imaging surface is the first for the objective lens system 20 having the front field of view. The imaging region 23 and the second imaging region 24 for the objective lens system 21 having a rear field of view are divided into two, and the imaging surface of the solid-state imaging device is provided via optical path conversion prisms 25 and 26 (indicated by hatching). It has a structure that forms an image.

  This structure will be described in detail with reference to FIGS. FIG. 5A simply divides the imaging surface 30 of the solid-state imaging device 22 into a first imaging area 23 and a second imaging area 24, and the optical axis of the objective lens system 20 is at the center 31 a of each imaging area. The optical axis of the objective lens system 21 is set at 31b, and the image formation size covering the first imaging area 23 and the second imaging area 24 is indicated by dotted lines 32a and 32b. An image by the objective lens system is generally circular, but in this case, the portion that can be used as an image is restricted by the shape of the solid-state imaging device, and the rectangle is maximum as shown in the figure. As is apparent from the drawing, in this case, since the overlapping portion 33 of the image shown by hatching is large, it is necessary to prevent this overlap with a mechanical field mask, but the structure becomes quite complicated.

  In order to avoid the above-described overlapping portion 33 of the image, the imaging range of the objective lens system is limited to 34a and 34b in the first imaging region 23 and the second imaging region 24 as shown in FIG. 5B. It is desirable to apply a structured objective lens system. However, in this case, the range that can be used as an image in the first imaging area 23 and the second imaging area 24 is a circle of 34a and 34b. Since the necessary range portion of the image by the objective lens is read as shown by the rectangle, the number of usable pixels is also limited.

  FIG. 5C shows a structure that compensates for the drawbacks shown in FIGS. 6A and 6B described above. In the first imaging area 23 and the second imaging area 24, the imaging surface is shown. An imaging lens system that covers an ¼ range of the imaging surface 30 by setting an optical axis 36a of an objective lens system having a front visual field on a diagonal line 30 of 30 and an optical axis 36b of an objective lens system having a rear visual field. Is used to prevent the respective imaging sizes from interfering with each other, and a necessary range portion as a large rectangular imaging area of an imaging area 37a by an objective lens system having a front visual field and an imaging area 37b by an objective lens system having a rear visual field Images can be obtained. In the description of this embodiment, the structure shown in FIG.

  As an example, when a solid-state image sensor with a high pixel of about 1.3 million pixels is used as the solid-state image sensor, the structure of FIG. As a result, practically sufficient image quality can be obtained.

  FIG. 6 is a perspective view of the image pickup unit of the present embodiment, in which 30 denotes an image pickup surface of the solid-state image pickup device 22. The objective lens system 20 having a front visual field forms an image of the front specimen on a part of the first imaging region 23 set on the imaging surface 30 via the right-angle prism 25 for optical axis conversion. Similarly, the objective lens system 21 having a rear field of view connects an image of the rear specimen to a part of the second imaging region 24 set on the imaging surface 30 via a right angle prism 26 for optical axis conversion. Image.

  By configuring the imaging unit in this way, an electronic endoscope having a field of view in two directions on a single solid-state imaging device can be easily configured with a simple mechanism. In this case, a part of the insertion portion of the image of the rear field of view is copied and part of the field of view is distorted. However, this part of the field of view can be observed by rotating the electronic endoscope.

  In the above-described embodiment, the optical axis for the front view and the rear view is assumed to be in the same direction with respect to the insertion direction 11 of the insertion portion. However, if an optical axis conversion prism having a different declination is used instead of a right-angle prism, Needless to say, a field of view in the perspective direction and the rear perspective direction can be obtained, and such a slightly inclined field of view direction is also included in the scope of the present invention.

  Normally, a video signal from one solid-state image sensor reads out all pixels at the same time, and the CCU performs signal processing and displays it as an image on a monitor. When two images are taken by setting the necessary range part of the image and the rear view image, a frame memory for storing the image is provided in the CCU, and the signal read from the solid-state image sensor is temporarily stored in the frame memory. Accordingly, the front visual field image and the rear visual field image can be read out simultaneously or individually and displayed as a video on the monitor.

  Such a method can be carried out in a general technical range when the number of pixels of the solid-state image sensor is limited. However, as described in the embodiments, a 1.3 million pixel class solid-state image sensor is used. In such a case, advanced technology is required to read out all pixels at 30 frames / second.

  If a CMOS sensor is used as the solid-state image sensor, it is easy to select the address of the pixel that forms the imaging surface of the solid-state image sensor and read out the required part, so the address of the front view image and the address of the rear view image When the video signal is read out by switching between the above, it is possible to easily select and display the image of the front view and the image of the rear view on the monitor.

  FIG. 7 illustrates the above-described embodiment. In the figure, reference numeral 40 denotes a 1.3 million pixel CMOS sensor, and hatched portion A indicates an imaging region with a front visual field, and B indicates an imaging region with a rear visual field. The CMOS sensor driving means 44 has part A and B area designation means 42 for performing partial readout of the imaging surface and an XY address control means 41 for the CMOS sensor. The readout of the A area and the B area is switched as a video signal. It can be read. The video signal is subjected to predetermined signal processing by the signal processing circuit 43, and the video can be displayed on the monitor 4 and observed through a path indicated by a chain line.

  In addition, when the A area and the B area are partially read out to be a video signal, the amount of signal information is in the VGA range, so the output signal from the signal processing circuit 43 is sent to the PC (via the USB-2 standard digital interface 46). PC) 47, and video can be displayed on a monitor on the PC. In this case, the power of the white light emitting diode for illumination can be supplied from the USB terminal on the personal computer side.

  As described above, when the front-view image and the rear-view image formed on the solid-state image sensor are switched by reading out the respective image areas, the electronic endoscope can be simply connected to the PC via the USB-2 interface. Since the apparatus is configured, it is possible to provide a system that is easy to use and easy to use.

1 is a basic configuration diagram of an electronic endoscope. Explanatory drawing of the visual field range by an electronic endoscope. 1 is a basic configuration diagram of an electronic endoscope according to the present invention. Structure explanatory drawing of the electronic endoscope insertion part front-end | tip. Explanatory drawing which shows the state of the image size at the time of arrange | positioning two objective lenses on one solid-state image sensor. FIG. 3 is a perspective explanatory view of an imaging unit used in an embodiment of the present invention. The block diagram of the electronic endoscope apparatus by the Example of this invention.

Explanation of symbols

1 Electronic endoscope 2 Camera control unit (CCU)
3 Light source 4 Monitor 5 Operation unit 6 Insertion unit 7, 21, 22 Objective lens system 8, 22 Solid-state imaging device 9 Light guide 25, 26 Optical axis conversion prism 27, 28 White light emitting diode 43 Signal processing circuit 46 USB interface

Claims (4)

  In an electronic endoscope apparatus in which an imaging unit including an objective lens system and a solid-state imaging device is arranged at the distal end of the insertion portion, one piece so that the imaging surface of the solid-state imaging device is parallel to the insertion axis direction of the insertion portion. The solid-state imaging device is arranged, the imaging surface of the solid-state imaging device is divided into two to form a first imaging region and a second imaging region, and an optical member that converts the optical axis is formed in the first imaging region. A first objective lens system having a front field of view with respect to the insertion direction of the endoscope insertion portion is attached to the second imaging region, and the endoscope imaging portion is inserted into the second imaging region via an optical member that converts the optical axis. An electronic endoscope apparatus having a structure in which a second objective lens system having a rear visual field in the insertion direction is mounted.   By simultaneously reading out the image formed in the first imaging region and the second imaging region of the solid-state imaging device as a video signal, applying the signal processing to the memory, and controlling the reading method from the memory, The image formed on the first imaging region and the image formed on the second imaging region on the screen of the display device are selected and displayed simultaneously or individually as images. Electronic endoscope device.   A necessary range portion of an image formed by the first objective lens system in the first imaging region of the solid-state imaging device and a necessary range portion of an image formed by the second objective lens system in the second imaging region are separately provided. 2. A solid-state image sensor reading control means for reading out as a video signal, and displaying an image in the first imaging area and an image in the second imaging area separately on the video display device. The endoscope apparatus described.   The video signal read from the solid-state image sensor is subjected to predetermined signal processing, and then transmitted to a personal computer via a USB2 standard digital interface to display the video on a personal computer video display device. The endoscope apparatus according to claim 3, wherein power is supplied from a USB2 terminal of a personal computer.

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