JP2018108174A - Endoscope apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soft endoscope apparatus capable of high-speed scanning in which a high resolution video technique can be applied.SOLUTION: An endoscope apparatus 100 of the invention comprises: an insertion part for including a mirror 113 which is a tubular insertion part to be inserted into a body cavity, scans a surface area of a subject 101 and reflects light acquired from a surface of a subject, an optic fiber for receiving light reflected from the mirror by a core and transferring the same, and an image forming optic system 116 for guiding the light which is transferred on the optic fiber to an imaging element 131; a scanning part for scanning a surface area of the subject for scanning the mirror so as to receive reflectance; and an imaging device having the imaging element 131 for receiving the reflectance from the surface area of the subject guided by a detection optic part on a pixel corresponding to a position of the subject, in which the surface area of the subject is divided into w pieces of small areas, the mirror has w pieces of MEMS mirrors corresponding to the small areas, and the optic fiber is a multi core fiber 115A having w pieces or more and 8×w pieces or less of cores.SELECTED DRAWING: Figure 2A

Description

  The present invention relates to an endoscope apparatus. Specifically, the present invention relates to an endoscope apparatus to which 8K high-resolution video technology is applied.

  A flexible endoscope for performing a minimally invasive operation by inserting an elongated insertion portion into a body cavity and photographing a state inside the body cavity has been widely used. Recently, the probability of cancer in Japanese people is about 50%, and the use of endoscopes tends to expand further.

  On the other hand, with the development of communication technology, image processing technology, and optical technology, high-resolution video technology called 4K and 8K is being put into practical use. By the way, the change of 2K → 4K → 8K is not only an increase in memory, but also qualitative technological innovation is occurring in the field of medical devices using endoscopes and the field of minimally invasive surgery. When the 8K high-resolution video technology is applied to the endoscope apparatus, for example, it becomes possible to recognize a surgical thin thread, a minute affected part of an organ, a boundary between an organ and a tissue, and observation at a cell level. As a result, the reliability and certainty of the operation are enhanced, and progress in medical technology is expected. That is, the distinguishability of the affected part of the organ is increased, and the risk of unexpectedly damaging other than the affected part is also reduced. In addition, the surgical field of view can be expanded, and it is easy to perform surgery even when the surgical scope is wide. This is convenient for confirming the position of the surgical instrument and avoiding interference between surgical instruments. In addition, large-screen observation is possible, and all the people involved in the operation can share the same image, which facilitates communication. Thus, the use of 4K / 8K high resolution video technology has great potential.

JP 2008-43763 A

  However, in order to use an 8K high-resolution image, scanning with irradiation light or imaging light requires a long time for scanning because of the large number of pixels. On the other hand, in order to make the moving image look smooth, the frame interval must be 0.03 sec or less. For this reason, there is a problem that the time required for scanning must be shortened.

  In a conventional flexible endoscope apparatus, for example, an optical fiber 7 and an actuator are arranged in a distal end unit attached to the distal end of an insertion portion, the actuator has a piezoelectric element, and the optical fiber is rotated at the resonance frequency of the piezoelectric element. Then, the light irradiated from the tip of the optical fiber is scanned in a spiral shape, and the light reflected from the subject is received by a photosensor to obtain a photographed image (see Patent Document 1). In order to scan a diagnostic part of a subject spirally using a flexible optical fiber, control is complicated and not easy, and correction of data is required. Further, since the mechanical movement of the piezoelectric element is used, it is difficult to increase the scanning speed.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an endoscope apparatus to which a high-resolution video technology can be applied and which can perform high-speed scanning.

  In order to solve the above-described problem, an endoscope apparatus 100 according to a first aspect of the present invention is a tubular insertion portion 110 that is inserted into a body cavity, as shown in FIGS. 1 and 2A, for example. A mirror 113 that scans the surface area of the subject 101 and reflects light acquired from the surface of the subject 101, an optical fiber 115 that receives and transmits the light reflected from the mirror 113 by the core, and light that is transmitted through the optical fiber 115 An insertion unit 110 that includes an imaging optical system 116 that leads to the image sensor 131, a scanning unit 146 that scans the surface 113 of the subject 101 and receives the reflected light, and an imaging optical system 116. And an imaging device 130 having an imaging device 131 that receives reflected light from the surface area of the subject 101 guided by the pixel 101 corresponding to the position of the subject 101, and the subject 101 surface area The multi-core is divided into w (integer of 2 or more) small areas, the mirror 113 has w MEMS mirrors corresponding to the small areas, and the optical fiber 115 has w or more and 8 × w or less cores. Fiber 115M.

Here, MEMS (Micro Electro Mechanical System) refers to a device in which mechanical parts and electronic circuits are integrated on a silicon substrate, a glass substrate or the like using a semiconductor microfabrication technique. The MEMS mirror 113 (i, j) refers to a micromirror manufactured so as to be tiltable on a substrate among such devices. For example, there is an electrostatic resonance mirror that moves the comb drive unit up and down using static electricity.
W is an arbitrary integer of 2 or more, and is m × n or less. At 8K, m = 7680 and n = 4320.

  With this configuration, it is possible to provide an endoscope apparatus that can apply high-resolution video technology and can perform high-speed scanning.

Moreover, the endoscope apparatus 100 according to the second aspect of the present invention is the endoscope apparatus according to the first aspect. For example, as shown in FIG. A pixel of 16K or less is mounted.
Here, “8K level” or “equivalent to 8K” refers to the degree of resolution equivalent to a high-definition resolution image that can be realized with 8K (7680 × 4320 pixels). However, in the real world, a resolution exceeding 4K resolution (3840 × 2160 pixels) may be used. Therefore, here, it is assumed that the resolution exceeds 6K resolution (specifically, the number of pixels in one frame is 20 million or more). Since it is “8K level or higher”, a pixel number of 8K resolution (7680 × 4320 pixels) or higher may be used. The reason why “16K level or lower” is set is that, since “realistic feeling felt by humans” does not change much at “8K level or higher”, it is considered that 16K or lower is sufficient for practical use.
With this configuration, high-definition resolution can be realized, which can greatly contribute to development in academic, medical and other fields.

Moreover, the endoscope apparatus according to the third aspect of the present invention is the endoscope apparatus according to the first aspect or the second aspect, wherein the objective optical system in the insertion portion 110 is a telecentric system.
With this configuration, since the scanning light beam reaching the subject can be converted into a parallel light beam by the objective optical system, each small region 101 (i, j, i, j) is controlled by aligning the angle and direction of each MEMS mirror 113 (i, j). The scanning in j) can be performed identically, and the scanning efficiency can be increased.

In addition, an endoscope apparatus 100 according to a fourth aspect of the present invention is an endoscope apparatus according to any one of the first to third aspects. For example, as shown in FIG. Each small area 101 (i, j) corresponding to i, j) is scanned simultaneously.
If comprised in this way, writing to the whole memory | storage part to an image pick-up element can be made efficient by scanning each MEMS mirror simultaneously in parallel. If there are m × n MEMS mirrors, the scanning time can be shortened to 1 / (m × n).

An endoscope apparatus according to the fifth aspect of the present invention is the endoscope apparatus according to any one of the first to fourth aspects. In the imaging optical system 116, the multicore fiber 115M and the imaging element 131 are arranged. There is an optical component for scanning the detection light between them and guiding it to the image sensor 131, and the scanning unit 146 scans the detection light using the optical component.
With this configuration, by scanning the surface of the image sensor, direct storage in RAM or ROM becomes possible, and the application range is expanded.

Further, an endoscope apparatus 100B according to a sixth aspect of the present invention is an endoscope apparatus according to any one of the first to fifth aspects. For example, as shown in FIG. The area of the small region 101 (i, j) scanned by i, j) can be changed by controlling the amount of change in the rotation angle of each MEMS mirror 113 (i, j). Can be electrically controlled by the amount of change in the rotation angle of the MEMS mirror 113 (i, j) using precise semiconductor integrated circuit technology, so that highly accurate control can be performed.

In addition, an endoscope apparatus according to a seventh aspect of the present invention is the endoscope apparatus according to any one of the first to sixth aspects. For example, as shown in FIG. 10A or FIG. The first mirrors 113A1 and 113B1 on the image sensor 131 side are fixed, and MEMS mirrors are used as the second mirrors 113A2 and 113B2 on the subject 101 side.
If comprised in this way, since the reflection angle of one reflective mirror (MEMS mirror) can be changed in a wide range, a scanning range can be enlarged and a scanning accuracy can be taken. Also, if the mirror surface is 45 degrees with the surface of the subject 101, the direction of the light twice the mirror rotation angle is rotated and adjustment is easy.

Further, an endoscope apparatus 100C according to an eighth aspect of the present invention is the endoscope apparatus according to any one of the first to seventh aspects, for example, as illustrated in FIG. 11A, adjacent to the multicore fiber 115M. Cores that transmit different colors of light.
If comprised in this way, the interference from an adjacent small area | region can be reduced.

In addition, an endoscope apparatus 100D (not shown) according to a ninth aspect of the present invention is an MEMS apparatus according to any one of the first to seventh aspects, for example, as shown in FIG. A grating 129 is applied to the mirror 113B so that the rotation angle of the adjacent MEMS mirror 113B is different.
If comprised in this way, the interference from an adjacent small area | region can be reduced.

Further, an endoscope apparatus 100A according to a tenth aspect of the present invention is a light source that emits illumination light as shown in FIG. 8, for example, in the endoscope apparatus according to any one of the first to ninth aspects. 125 and an illumination optical system 120A having an optical transmission path for transmitting illumination light emitted from the light source 125 to the surface of the subject 101, and a multi-core fiber 115M is used as the optical transmission path.
If comprised in this way, the light which irradiates each small area | region can be equalized by aligning the light quantity supplied to a multi-core fiber, and the uniformity of an image quality can be improved by extension.

An endoscope apparatus according to an eleventh aspect of the present invention is the endoscope apparatus according to any one of the first to tenth aspects, wherein the core of the multi-core fiber 115M corresponds to w MEMS mirrors 113. A × w.
Here, a is an integer of 2 or more, but 16 or less is practical. If comprised in this way, since it respond | corresponds to the light input / output to a core with one MEMS mirror 113, it can respond also to a high-density multi-core fiber, and since a MEMS mirror can be made comparatively large, MEMS mirror It is easy to manufacture.

  According to the present invention, it is possible to provide an endoscope apparatus to which high-resolution video technology can be applied and which can perform high-speed scanning.

It is a figure for demonstrating the structure of an endoscope apparatus. 1 is a diagram illustrating a configuration example of an optical system of an endoscope apparatus according to Embodiment 1. FIG. It is a figure which shows the matrix arrangement | positioning of the MEMS mirror in FIG. 2A. It is a block diagram which shows the structural example of an illuminating device. It is a block diagram which shows the structural example of an imaging device. It is a block diagram which shows the structural example of a control apparatus. It is a figure for demonstrating the pixel pitch of an image pick-up element. It is a figure for demonstrating a large screen monitor. FIG. 10 is a diagram illustrating a configuration example of an endoscope apparatus according to a second embodiment. FIG. 10 is a diagram illustrating a configuration example of an endoscope apparatus according to a third embodiment. It is a figure which shows the variation (the 1) of division scanning. It is a figure which shows the variation (the 2) of division scanning. FIG. 10 is a diagram illustrating a configuration example of an endoscope apparatus according to a fifth embodiment. It is a figure for demonstrating the change of the color of the color filter in FIG. 11A. It is a figure for demonstrating the relationship between a grating and a reflection angle.

  An endoscope apparatus according to an embodiment of the present invention will be described below in detail with reference to the drawings.

  In this embodiment (see FIGS. 1 and 2A), an example in which the MEMS mirror 113 arranged in a matrix is used for scanning the subject 101 will be described. The endoscope apparatus 100 according to the present embodiment is a flexible endoscope mainly used for a digestive system. The surface of the subject 101 is divided corresponding to the MEMS mirror 113, and each image data of the subject 101 obtained by scanning each MEMS mirror 113 is divided into each divided region by each MEMS mirror 113. The image is input to the core and imaged on the image sensor 131 through each core. Each small area 101 (i, j) divided on the surface of the subject 101, each MEMS mirror 113 (i, j), and each core of the multi-core fiber 115M are in a corresponding relationship.

〔Device configuration〕
FIG. 1 is a diagram for explaining the configuration of the endoscope apparatus 100X. In order to facilitate understanding of the present embodiment, FIG. 1 shows an example in which the core of the MEMS mirror 113 and the imaging optical fiber 115 is one. The endoscope apparatus 100 includes an insertion unit 110, an illumination device 120, an imaging device 130, a control device 140, and a display device 150. In this embodiment, the MEMS mirror 113 is arranged in a matrix, and a multi-core fiber 115M (see FIG. 2A) is used as the optical fiber for the imaging system.

  FIG. 2A shows a configuration example of the scanning endoscope apparatus 100 according to the first embodiment. FIG. 2B is a diagram showing a matrix arrangement of the MEMS mirror.

  The insertion portion 110 is an elongated flexible member that is inserted into a body cavity of a subject or the like. The insertion portion 110 includes a tubular portion 111, an objective lens 112, a MEMS mirror 113, a multicore fiber 115M, and an imaging optical system 116.

The tubular portion 111 is a member formed of a flexible resin material or the like, for example, in a cylindrical shape or an elliptical cylindrical shape having a diameter of 3 mm to 9 mm, and has a length of 1 to 2 m. At the distal end of the tubular portion 111, the reflected light from the subject 101 is transmitted, a transparent plate (not shown) that seals the inside of the tubular portion 111, and the reflected light that has passed through the transparent plate is received and reflected in the direction of the optical fiber 115. And an objective lens 112 that guides the reflected light reflected by the MEMS mirror 113 to the optical fiber 115. There is an optical fiber 115 that detects the reflected light from the MEMS mirror 113 and transmits it to the imaging device 130.
The surface of the subject 101 is scanned using the MEMS mirror 113, and the reflected light from the subject 101 is received and reflected in the direction of the optical fiber 115. The optical axis direction of the optical fiber 115 is matched with the direction of the center line of the tubular portion 111. For example, when the MEMS mirror 113 is rotated in the plane including the optical axis and around the optical axis, the laser beam can be scanned in the radial direction and the circumferential direction on the surface of the subject 101. Further, scanning in the x direction and the y direction can be performed by a combination of the radial direction and the circumferential direction. For example, if the scanning frequency is 100 kHz, 4000 scans can be scanned in 400 ms. The imaging device 130 is detachably attached to the proximal end portion of the insertion portion 110.

  The side surface of the transparent plate (provided at the distal end of the insertion portion 110 or the side surface where scanning light enters and exits) is fixed to the inner wall surface near the distal end of the tubular portion 111 using an adhesive or the like, and the distal end of the insertion portion 110 is sealed. The The transparent plate is used to stabilize and seal the tip of the insertion portion 110. The objective lens 112 collects the reflected light from the MEMS mirror 113 and guides it to the optical fiber 115 (multi-core fiber 115M).

  The multi-core fiber 115 </ b> M receives light having the subject 101 information reflected by the MEMS mirror 113 and transmits the light in the direction of the imaging device 130. Each core receives light from each MEMS mirror 113 and transmits it. The imaging optical system 116 images the light from the multi-core fiber 115M on the image sensor 131. The image sensor 131 may receive the light from each core of the multi-core fiber 115M by dividing the light into respective blocks. If the image sensor 131 is, for example, a CCD or a CMOS, the reflected light from each small area of the subject 101 obtained by scanning can be received in time series and sequentially stored in the storage unit 143.

FIG. 3 is a block diagram illustrating a configuration example of the lighting device. The illumination device 120 includes a light source 125 that emits light that illuminates the subject 1, and a first driver circuit 126 that drives the light source 125. For example, an LED element can be used as the light source 125. LEDs are often used for illumination because they can have a wide spectral width and a wide irradiation direction. A visible light semiconductor laser (such as a GaN semiconductor laser) can also be used. Laser light is suitable for control due to its high coherency, narrow wavelength width, narrow beam, and the like compared to LED light.
The first driver circuit 126 drives the light source 125 according to the control of the control device 140.

  FIG. 4 is a block diagram illustrating a configuration example of the imaging apparatus. The imaging device 130 is detachably attached to the proximal end portion of the insertion unit 110 and takes reflected light from the subject 101 into the imaging device 131. Then, an image of the subject 101 is captured, and the captured image is supplied to the control device 140. Specifically, the imaging device 130 includes an imaging element 131, a second driver circuit 132, an A / D conversion unit 133, and a transmission unit 134.

The second driver circuit 132 controls the start and end of imaging of the image sensor 131 according to the control of the control device 140, and reads the voltage signal (pixel voltage) of each pixel.
The A / D conversion unit 133 converts the pixel voltage read from the image sensor 131 by the second driver circuit 132 into digital data (image data), and outputs the digital data to the transmission unit 134.
The transmission unit 134 outputs the digital data (luminance data) output from the A / D conversion unit 133 to the control device 140.

  FIG. 5 is a block diagram showing the configuration of the control device 140. The control device 140 controls the entire endoscope apparatus 100, and includes a control unit 141, an image processing unit 142, a storage unit 143, an input / output IF (interface) 144, an input device 145, and a scanning unit 146.

  The control unit 141 includes a CPU (Central Processing Unit), a memory, and the like, and causes the storage unit 143 to store the luminance data transmitted from the transmission unit 134. Further, the image processing unit 142 processes the image data and displays it on the display device 150. The control unit 141 further controls the first driver circuit 126, the second driver circuit 132, and the scanning unit 146.

  The image processing unit 142 includes an image processor and the like, processes image data stored in the storage unit 143 under the control of the control unit 141, reproduces image data (frame data) for one frame, and stores the storage unit. Re-accumulate at 143. In addition, the image processing unit 142 performs various image processes on the image data in units of frames stored in the storage unit 143. For example, the image processing unit 142 performs an enlargement / reduction process for enlarging / reducing each image frame at an arbitrary magnification.

  Digital zoom is used for enlargement / reduction. In 8K, an image of the minimum dimension (maximum magnification) to be observed is clearly stored in the image sensor and displayed on the entire large screen. That is, since a clear image is stored in the storage unit 143, the image is not blurred even if the image is enlarged or reduced by the digital zoom. For this reason, since an image in a wide visual field range can be clearly displayed, a wide visual field can be provided. In addition, when digital zoom is used in combination with image processing (sharpening processing), a clearer image can be obtained by, for example, expressing the contrast between the affected part and another part with emphasis.

  The storage unit 143 stores an operation program of the control unit 141, an operation program of the image processing unit 142, image data received from the transmission unit 134, frame data reproduced by the image processing unit 142, processed frame data, and the like.

  The input / output IF 144 functions as an interface for data transmission / reception between the control unit 141 and an external device. The input device 145 includes a keyboard, a mouse, a button, a touch panel, and the like, and supplies a user instruction to the control unit 141 via the input / output IF 144.

  The scanning unit 146 controls the direction and the rotation angle of the MEMS mirror 113 by the control unit 141 to scan and extract the reflected light from the surface of the subject 101. For example, the rotation angle of the MEMS mirror 113 is controlled by an electrostatic driving method or an electromagnetic driving method. Since control is possible for each MEMS mirror 113 arranged in a matrix, m × n small regions can be driven separately and simultaneously. Thereby, the scanning time of the surface of the subject 101 can be shortened to 1 / (m × n).

The display device 150 is configured by a liquid crystal display device or the like having a display pixel number corresponding to 8K, and displays an operation screen, a captured image, a processed image, and the like under the control of the control device 140.
At 8K, a large screen monitor can be used for the display device. Since the storage unit 143 stores 7680 × 4320 pixels, for example, a large screen monitor of 30 inches or more is used. It looks natural even on a large screen monitor. For this reason, all the persons involved in the operation can share a large screen image, and smooth communication can be achieved. The surgeon can also see the branch image from the imaging device.

[Division scanning]
FIG. 2A is a diagram illustrating a configuration example of an optical system of the scanning endoscope apparatus 100 according to the first embodiment. That is, an example having a configuration for dividing and scanning is shown. In this embodiment, an example using MEMS mirrors (micromirrors) 113 arranged in a matrix will be described. FIG. 2B is a diagram showing a matrix arrangement of the MEMS mirror 113. Corresponding to the m × n small area into which the subject 101 is divided, m × n MEMS mirrors 113 (i, j) (113 in total) are arranged in one plane.
An m × n MEMS mirror 113 (i, j) is provided corresponding to the area of the subject 101 corresponding to m × n small areas, and each mirror 113 (i, j) scans each corresponding small area. To do. When the mxn mirrors 113 (i, j) are scanned in parallel, the scanning time can be shortened to 1 / (mxn) compared to scanning the entire mirror with one mirror, and the tilt control angle is also approximately x. The direction becomes 1 / m and the y direction becomes 1 / n. Thereby, the scanning time can be shortened, and the tilt control angle can be reduced.
Further, in FIG. 2A, the relative position of the scanned object with respect to the tubular portion 111 and the positions of the objective lens 112 and the object 101 are different from those in FIG. Other configurations are the same as those in FIG.

  The reflected light from each small area 101 (i, j) of the illuminated subject reaches each MEMS mirror 113 (i, j) and then is reflected by each MEMS mirror 113 (i, j), and the objective lens 112 ( The light enters the m × n cores of the multi-core fiber 115M through the subject side lens 112A, the stop 112B, and the imaging side lens 112C). In this case, each small area 101 (i, j) of the subject is designed to be confocal with the corresponding core at each incident end of the multi-core fiber 115M, and reflected light from the small area that does not correspond is incident on the core. It is supposed not to. The light (image data) transmitted through the multi-core fiber 115M is imaged by the image sensor 131 through the imaging optical system 116. Then, if the image sensor 131 is divided into m × n blocks and associated with m × n cores, the output light from each core is received by the corresponding block of the image sensor 131. In addition, light reception to the image sensor 131 can be performed in parallel. In addition, it is preferable that writing from the image sensor 131 to the storage unit 143 is performed in parallel by circuit control. The image processor (image processing unit) 142 displays the image data written in the storage unit 143 on the display (display device) 150. In addition, it is preferable to perform writing from the storage unit 143 to the display 150 in parallel.

The MEMS mirror 113 is configured to be rotatable around two axes (x-axis and y-axis) orthogonal to each other in the arrangement plane or in the radial direction and the circumferential direction. The light reflected from the small area of the subject 101 enters each mirror 113 and is reflected in a direction that is symmetric with respect to the incident direction with respect to the central axis of the mirror 113. For example, the reflection direction is changed by rotating the tilt of the mirror 113 around two axes (x-axis and y-axis) orthogonal to each other in the arrangement plane, or in the radial direction and the circumferential direction. The light from the selected position can be guided to the mirror 113. The scanning direction is two directions x and y, and the subject 101 is scanned in-plane.
A captured image captured by the imaging device 130 is transmitted to the image processor 142. The image processor 142 performs image processing on the transmitted captured image or displays it on the display 150 as it is.

  When the inclination of the MEMS mirror 113 with respect to the central axis direction of the tubular portion 111 is about 45 degrees, scanning can be easily controlled. In this case, the position of the subject 101 is located on the side surface of the tubular portion 111, but is suitable for scanning the digestive organs. Further, since the MEMS mirror 113 is disposed closer to the subject 101 than the objective lens 112 (subject side lens 112A, stop 112B, and imaging side lens 112C), the objective lens 112 has a role of making the inside of the tubular portion 111 airtight. Although not shown, a transparent plate disposed closer to the subject 101 than the MEMS mirror 113 serves to make the inside of the tubular portion 111 airtight.

It is also possible to control each MEMS mirror 113 (i, j) to scan each corresponding small region 101 (i, j) at the same time. In such a configuration, the entire storage in the image sensor can be made efficient by scanning each MEMS mirror simultaneously and in parallel. If there are m × n MEMS mirrors, the scanning time can be reduced to 1 / (m × n).
When the stop 112B is placed at the focal point of the subject side lens 112A, the light rays on the subject side become parallel, and the objective optical system in the insertion unit 110 becomes a telecentric system. In such a configuration, by controlling the MEMS mirrors 113 (i, j) to have the same angle and orientation, the scanning in each of the small regions 101 (i, j) can be performed in the same manner, and the scanning efficiency can be improved. .

[8K image sensor]
FIG. 6 is a diagram for explaining the pixel pitch of the image sensor 131. The image sensor 131 is a so-called 8K, that is, a color image sensor having 7680 × 4320 pixels (pixels). Therefore, according to the 8K endoscope apparatus 100, a high-definition captured image can be obtained.

  FIG. 7 is a diagram for explaining the large screen monitor. The number of pixels of the 8K monitor 302 (33 million) is 16 times the number of pixels of the 2K monitor 301 (2 million). Since the number of pixels = field of view (monitor area) × pixel density, if the field of view is 4 times 2K, the pixel density is 4 times 2K. That is, it is possible to provide an image with a wider field of view and higher definition than 2K. If the image sensor has 4 pixels of R (red), G (green), G (green), and B (blue) as a unit area and a 1 μm square image is taken there, the object 101 is 3.8 mm × 2.15 mm The area can be stored in the 8K storage element and displayed on the entire 8K screen. This can be reduced and displayed, or a part can be cut out and displayed. If the screen of the 8K storage element is clear, it is clear even if it is reduced. Note that three pixels of R (red), G (green), and B (blue) may be used as a unit region.

However, if the number of pixels of the image sensor (imaging device) 131 is simply set to 8K (7680 × 4320 pixels), a true resolution (image density) of 8K can be realized on the display device (display) 150. Not necessarily.
In order to realize a truly 8K resolution, it is necessary that “the pixel size is large”. If the pixel size of the image sensor 131 is too small, the image cannot be resolved due to the light diffraction limit, resulting in a blurred image. When applied to a flexible endoscope, it is difficult to use a large image sensor as an imaging device to be mounted on the distal end due to the restriction of being inserted into a body cavity.

  Further, it is conceivable that the diameter of the light guided through the endoscope is expanded to the full extent by the magnifying lens. However, the higher the magnification (the longer the focal length), the larger the imaging area on the screen, but the surgical field range for obtaining reflected light becomes narrower. For this reason, there is a problem that the amount of light (photons) received by the image sensor 131 is reduced and the image becomes dark. This problem can be solved by the fact that the sensitivity of the image sensor 131 is quadrupled at 8K and the liquid crystal monitor becomes brighter.

  In order to achieve 8K resolution, the pixel pitch P of the image sensor 131 is set to be larger than the diffraction limit of the main light used for illumination of the subject 101. Specifically, the pitch P is set to a value larger than the reference wavelength λ corresponding to the wavelength of the illumination light, that is, the wavelength of the light emitted from the light source (LED element, semiconductor laser element, etc.) 125. When the illumination light includes light of a plurality of wavelengths, the reference wavelength λ means the light having the longest wavelength among the three primary colors constituting the illumination light, that is, the wavelength of the main component of red light. That is, it means the wavelength having the largest energy in the spectral region corresponding to red.

  Further, when the brightness of the lens system is increased (F value is decreased), the brightness becomes brighter but the depth of field becomes shallower. Increasing the F value increases the depth of field but darkens it. For this reason, it was found that an aperture (f value) of 10 to 16 and a pixel pitch (pixel pitch) P of 2.8 to 3.8 μm are appropriate at 8K. If the pitch is too small, interference occurs and the image is blurred. If it is too large, the substrate becomes large, which is disadvantageous in terms of volume, weight and speed. 3.0 to 3.5 μm is more suitable. When the pixel pitch P is 2.8 to 3.8 μm, the size of the image sensor 131 is about 20 to 30 mm × 12 to 18 mm.

Assuming that the viewing angle for viewing the monitor screen is 30 degrees at 2K, 60 degrees at 4K, and 100 degrees at 8K, the realistic sensation is almost saturated at 100 degrees, so 8K is sufficient to obtain a realistic sensation.
The image sensor 131 may include pixels equivalent to 8K or more. In the real world, even if the number of elements is 8K or less, a clear image can be obtained as compared with 4K. For this reason, the number of pixels of 6K or more is equivalent to 8K.

[Description of operation]
Next, the operation of the endoscope apparatus 100 having the above configuration will be described.
When using the endoscope apparatus 100, the user (practitioner) operates the input device 145 (see FIG. 5) and instructs the endoscope apparatus 100 to be turned on. In response to this instruction, the control unit 141 turns on the first driver circuit 126 and the second driver circuit 132.
The first driver circuit 126 turns on the light source (LED element 125 and the like) (see FIG. 3), and the second driver circuit 132 starts imaging by the image sensor 131 (see FIG. 4).
The light output from the LED element 125 is irradiated by the illumination device 120 so as to diffuse, for example, at a wide angle.

  The multi-core fiber 115M receives the reflected light incident through the objective lens 112. The received light is made to correspond to the irradiation position of the subject 101 and written into the corresponding memory of the storage unit 143 via the image sensor 131, thereby capturing an image of the subject 101. From the relationship between the aperture (f value) of the lens system and the pixel pitch P of the image sensor 131, the pixel pitch P is preferably 2.8 to 3.8 μm, and the pixel pitch P in this range is used. did. For this reason, a bright and high-resolution image can be acquired.

  The second driver circuit 132 sequentially reads the pixel voltage of each pixel from the image sensor 131, converts the pixel voltage into digital image data by the A / D conversion unit 133, and sequentially transmits the digital image data from the transmission unit 134 to the control device 140 via a cable. To do.

The control unit 141 of the control device 140 sequentially receives the transmitted image data via the input / output IF 144 and sequentially stores them in the storage unit 143.
The image processing unit 142 processes the image data stored in the storage unit 143 under the control of the control unit 141, reproduces the frame data, and appropriately performs a processing process.
The control unit 141 appropriately reads the frame data stored in the storage unit 143, supplies the frame data to the display device 150 via the input / output IF 144, and displays the frame data.

  The user (practitioner) inserts the insertion unit 110 into the body cavity while confirming the display on the display device 150. When the insertion unit 110 is inserted into the body cavity, the subject 101 is illuminated with the light guided from the light source 125, and the image sensor 131 captures an image of the subject 101, and the captured image is displayed on the display device 150.

  As described above, according to the present embodiment, it is possible to provide an endoscope apparatus that can apply high-resolution video technology and can perform high-speed scanning.

  In the first embodiment, the example in which the MEMS parallel scanning is used in the imaging system has been described. In the second embodiment, an example in which the MEMS parallel scanning is also used in the illumination optical system will be described. The aspects different from the first embodiment will be mainly described.

  FIG. 8 shows a configuration example of an endoscope apparatus 100A according to the second embodiment. That is, a configuration for dividing and scanning is shown. The matrix arrangement of the MEMS mirror is the same as that in FIG. 2B. Instead of the illumination device 120 of the first embodiment, an illumination optical system 120A is used. The illumination optical system 120A groups the light source 125 that emits light that illuminates the subject 101, the first driver circuit 126 that drives the light source 125, and the light emitted from the light source 125, and each core of the multi-core fiber 115M. Illumination lens system (for example, collimator lens 127 + half mirror 128) to be input to the multi-core fiber 115M that transmits the light input to each core by the illumination lens system to the vicinity of the MEMS mirror 113, and each of the multi-core fiber 115M And a MEMS mirror 113 that scans each group light in parallel with each region of the surface of the subject 101. Here, in the illumination optical system 120A, a multi-core fiber 115M and a MEMS mirror are used as an optical transmission path for transmitting illumination light emitted from the light source 125 to the surface of the subject 101. In such a configuration, by aligning the amount of light supplied to the multi-core fiber 115M, the light irradiating each small region 101 (i, j) can be made uniform, and as a result, the uniformity of the image quality can be improved.

  For example, an LED element can be used as the light source 125. When an LED element is used, the emitted light is easily divided into a matrix. The light output from the light source 125 is reflected by the half mirror 128 as a substantially parallel light beam by the collimator lens 127 and is incident on the m × n cores of the multi-core fiber 115M. The light of each group output from the multi-core fiber 115M is applied to m × n mirrors 113 (i, j) of the MEMS.

  In the scanning unit 146, the tilt angle of each MEMS mirror 113 is controlled by the control unit 141, and irradiation light emitted from each core of the multicore fiber 115 </ b> M is irradiated to each of m × n small regions on the surface of the subject 101. . By controlling the tilt angle of each mirror 113 in the xy direction, m × n small regions are scanned in the xy direction, and as a result, the entire target region is scanned. Parallel scanning of mxn mirrors 113 (i, j) of the MEMS matrix is possible. As a result, the scanning time becomes 1 / (m × n), and a large time reduction effect is obtained.

The reflected light from the subject 101 is generally scattered in multiple directions, but the light scattered in the direction in which each core of the multi-core fiber 115M is present is detected. That is, if the relationship between the position of the subject 101 and the position of the exit of the multicore fiber 115M is adjusted so that the irradiation position of each small area on the surface of the subject 101 and the exit of each multicore fiber 115M have a confocal relationship, The reflected light from the region returns to the exit of the core that is in the correspondence relationship of the multi-core fiber 115M, and does not enter the exit of other cores that are not in the correspondence. The time from when the light is emitted from the MEMS mirror 113, incident on the subject 101, reflected, and reaches the mirror 113 is instantaneous, and the inclination of the mirror 113 during that time can be regarded as constant. Then, the light follows the original path, passes through the objective lens 112, passes through the multi-core fiber 115M, and then reaches the imaging optical system 116. Since the irradiation position on the surface of the subject 101 is changed by the scanning, data is written in the storage unit 143 via the image sensor 131 in time series corresponding to the irradiation position.
The reflected light that has returned to the exit of the multi-core fiber 115M is transmitted in the reverse direction through the multi-core fiber 115M, passes through the half mirror 128 via the imaging optical system 116, and reaches the image sensor 131. The configuration from the multi-core fiber 115M to the imaging optical system 116 is the same as that of the first embodiment except that it passes through the half mirror 128.

  The configuration of the apparatus other than the illumination optical system and the imaging system (half mirror) is the same as that of the first embodiment. As in the first embodiment, an endoscope apparatus that can apply high-resolution image technology and can perform high-speed scanning is provided. Can be provided.

FIG. 9 shows a configuration example of the endoscope apparatus 100B according to the third embodiment. The difference from FIG. 2A is that the area of the scanning region is made smaller. That is, the scanning width is shortened by reducing the rotation width of the mirror in the xy directions. Compared to the first embodiment, the area of the scanning region is reduced, and the area written in the image sensor 131 having the same number of pixels is reduced, so that the display can be performed with higher resolution.
Other apparatus configurations are the same as those in the first embodiment, and as in the first embodiment, it is possible to provide an endoscope apparatus that can apply a high-resolution video technology and can perform high-speed scanning.

10A and 10B show variations of division scanning. FIG. 10A shows an example in which the mirror is constituted by a plane mirror as an example of reflection twice by the MEMS mirror. The first mirror 113A1 is fixed, and scanning is performed using the second mirror 113A2. This is suitable for irradiating the subject 101 in front of the insertion unit 110. FIG. 10B shows an example in which the first mirror 113B1 is formed of a convex mirror and the second mirror 113B2 is formed of a concave mirror. The first mirror 113B1 is fixed, and the second mirror 113B2 is scanned. A MEMS mirror is used as the second mirror 113B2.
With this configuration, the reflection angle of one of the reflecting mirrors (MEMS mirrors) 113A2 and 113B2 can be changed over a wide range, so that the scanning range can be increased and the scanning accuracy can be increased.
If the mirror surface is 45 degrees with the surface of the subject 101, the laser direction is rotated twice the mirror rotation angle, and adjustment is easy.
Other apparatus configurations are the same as those in the first embodiment, and as in the first embodiment, it is possible to provide an endoscope apparatus that can apply a high-resolution video technology and can perform high-speed scanning.

  In the above embodiment, an example in which all the colors of RGB (that is, white light) are detected by each MEMS has been described. However, since scanning is performed in parallel by all the MEMS, there is a concern about the possibility of crosstalk. Therefore, in this embodiment, an example will be described in which the color detected by the adjacent MEMS is changed in order to avoid crosstalk. A color filter 117 is inserted in the optical path of the irradiation light or the optical path of the detection light.

FIG. 11A shows an example in which a color filter 117 is inserted in the optical path of irradiation light. That is, it is a diagram illustrating a configuration for performing division scanning. The matrix arrangement of the MEMS mirror is the same as that in FIG. 2B. FIG. 11B is a diagram for explaining the change of the color filter. For example, a color filter 117 arranged in an m × n matrix is inserted between the objective lens 112 and the MEMS mirror 113. Here, the adjacent mirrors 113 have different colors as shown in FIG. 11B, for example.
For example, four regions are grouped as one group, and R (upper left), G (upper right), G (lower left), and B (lower right) are arranged, and this is repeated in the x direction and the y direction. Thereby, since the light irradiated to each adjacent small region 101 (i, j) of the subject and each adjacent MEMS mirror 113 (i, j) has a different color (frequency), crosstalk can be suppressed. However, as it is, all colors cannot be obtained in each region and cannot be combined with actual colors. For example, as shown in FIG. 11B, the color filter 117 is sequentially moved so that one color has four regions as indicated by arrows. To repeat this movement. As a result, RGB can be detected in any region, and an actual color can be realized by synthesis.
Other apparatus configurations are the same as those in the first embodiment, and as in the first embodiment, it is possible to provide an endoscope apparatus that can apply a high-resolution video technology and can perform high-speed scanning.

  In the fifth embodiment, an example in which a color filter is used to change the color detected by the image sensor has been described. However, in this embodiment, a grating 129 is applied to the MEMS mirror and the tilt of the MEMS mirror 113C is adjusted to adjust the image sensor. An example of changing the color detected in 131 will be described.

FIG. 12 is a diagram for explaining the relationship between the grating 114 and the reflection angle. When a grating (periodic unevenness) 129 is applied to the surface of the MEMS mirror 113C, the reflection angle changes depending on the wavelength due to an action similar to a diffraction grating. That is, the reflection angle increases in the order of red, green, and blue. Therefore, by controlling the tilt angle of the MEMS mirror 113C by the control unit 141 (see FIG. 5), the light of the color selected from the reflected light from the surface of the subject 101 reaches the core of the corresponding multicore fiber 115M. Can do.
Thereby, the color detected by the image sensor 131 can be set to the selected color, and the color can be changed periodically.
Other apparatus configurations are the same as those in the first embodiment, and as in the first embodiment, it is possible to provide an endoscope apparatus that can apply a high-resolution video technology and can perform high-speed scanning.

  In the above embodiment, the example in which the illumination optical system or the detection optical system is scanned on the objective lens 112 side of the optical fiber 115 has been described. In this embodiment, the detection optical system is scanned on the imaging device 130 side of the optical fiber 115. An example will be described. That is, the imaging optical system 116 has an optical component for scanning the detection light between the multi-core fiber 115M and the image sensor 131 and guiding it to the image sensor 131, and the scanning unit 146 uses the optical component to detect the detection light. Scan. In such a configuration, by scanning the surface of the image sensor 131, direct storage in the RAM or ROM becomes possible, and the application range is expanded.

In the above embodiment, an example in which the number of cores of the multi-core fiber is equal to the number of MENS lenses has been described. However, in this embodiment, the number of cores a × w (a is a positive integer) of the multi-core fiber is greater than the number of MEMS lenses w. A large example will be described.
That is, the number of cores of the multi-core fiber 115 </ b> M is a × w corresponding to the w MEMS mirrors 113. For example, the MEMS mirror 113 is manufactured horizontally and four light beams from four cores are applied to the mirror in parallel. If the scanning direction is the vertical direction, light from the four cores can be scanned simultaneously. However, a is not limited to 4 and may be a positive integer of 2 or more, but 2 ≦ a ≦ 16 is appropriate for practical use.
If comprised in this way, since it respond | corresponds to the light input / output to a core with one MEMS mirror, it can respond also to a high-density multi-core fiber, and since a MEMS mirror can be made comparatively large, a MEMS mirror can be used. Easy to manufacture.

  Although the present embodiment has been described above, the present invention is not limited to the above embodiment, and it is obvious that various modifications can be made to the embodiment without departing from the spirit of the present invention. is there.

  For example, in the present embodiment, an example in which parallel scanning is used for a flexible endoscope has been described, but the present invention can also be applied to a rigid endoscope. Further, in this embodiment, an example in which the subject is mainly in the side surface direction of the insertion portion has been described. However, when the subject is in front of the insertion portion, the scanned light as shown in FIG. It is also possible to emit in the same direction as the axial direction. Further, if the MEMS mirror is configured to be rotatable around the central axis of the insertion portion, imaging of the entire periphery of the insertion portion becomes possible. Further, the detection sensitivity may be increased by using an ultra-sensitive HARP (High-Gain Avalanche Rushing amorphous Photoconductor) imaging plate that uses the avalanche multiplication phenomenon in the photoelectric conversion film as the imaging device. In this case, after the image sensor detects a signal, it is configured to write to the memory immediately so that the next signal can be detected. The parallel operation is preferably applied to light reception from the multi-core fiber to the imaging device, writing from the imaging device to the storage unit, and data transmission from the storage unit to the display. In addition, the shape and dimensions of each part of the endoscope apparatus, the number and arrangement of MEMS mirrors, the dimensions of the image sensor and the image monitor, and the like can be appropriately changed within an appropriate range.

  The present invention is used in an endoscope apparatus.

100, 100A to 100C, 100X Endoscopic device 101 Subject 101 (i, j) Minute area of subject 110 Insertion portion 111 Tubular portion 112, 112A1, 112A2 Objective lens 112A Subject side lens 112B Aperture 112C Imaging side lens 113 Mirror 113A1 , 113A2, 113B1, 113B2, 113C MEMS mirror 113 (i, j) MEMS mirror 115 Optical fiber 115M Multi-core fiber 116 Imaging optical system 117 Color filter 118 Half mirror 120 Illumination device 120A Illumination optical system 125 Light source (LED element)
126 First Driver Circuit 127 Collimator Lens 128 Half Mirror 129 Grating 130 Imaging Device 131 Image Sensor (Image Sensor)
132 Second Driver Circuit 133 A / D Converter 134 Transmitter 140 Controller 140 Controller 142 Image Processor (Image Processor)
143 Storage unit 144 Input / output IF
145 Input device 146 Scanning unit 150 Display device (display)

Claims (11)

A tubular insertion portion that is inserted into a body cavity, a mirror that scans a subject surface region and reflects light acquired from the subject surface, and light that is received by the core and transmitted by the core. An insertion portion including a fiber and a detection optical system that guides light transmitted through the optical fiber to an imaging device;
A scanning unit that scans the mirror so as to acquire light from the subject surface region;
An imaging device having an imaging element that receives light from the surface area of the subject guided by the detection optical system to a pixel corresponding to the position of the subject;
The subject surface area is divided into w (integer of 2 or more) small areas, the mirror has w MEMS mirrors corresponding to the small areas, and the optical fibers are not less than w and 16 × w. A multi-core fiber having the following cores;
Endoscopic device. In the imaging apparatus, the imaging element includes pixels of 8K level to 16K;
The endoscope apparatus according to claim 1. The objective optical system is a telecentric system in the insertion portion;
The endoscope apparatus according to claim 1 or 2. Each MEMS mirror simultaneously scans each corresponding subregion;
The endoscope apparatus according to any one of claims 1 to 3. The detection optical system includes an optical component for scanning the detection light between the multi-core fiber and the image sensor and guiding the detection light to the image sensor, and the scanning unit uses the optical component to detect the detection light. Scan;
The endoscope apparatus according to any one of claims 1 to 4. The area of the small region scanned by each MEMS mirror can be changed by controlling the amount of change in the rotation angle of each MEMS mirror;
The endoscope apparatus according to any one of claims 1 to 5. The mirror has a two-stage configuration, the first mirror on the image sensor side is fixed, and the MEMS mirror is used as the second mirror on the subject side;
The endoscope apparatus according to any one of claims 1 to 6. Adjacent cores of the multi-core fiber transmit different colors of light;
The endoscope apparatus according to any one of claims 1 to 7. A grating is applied to the MEMS mirror, and the rotation angles of adjacent MEMS mirrors are set to different rotation angles;
The endoscope apparatus according to any one of claims 1 to 7. An illumination optical system having a light source that emits illumination light and an optical transmission path that transmits the illumination light emitted from the light source to the surface of the subject, and uses the multi-core fiber as the optical transmission path;
The endoscope apparatus according to any one of claims 1 to 9. The core of the multi-core fiber is a × w corresponding to the w MEMS mirrors;
The endoscope apparatus according to any one of claims 1 to 10.

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