Endoscope system and control method

Abstract

An endoscope system comprising: an endoscope including an imaging element for imaging the body cavity and the lumen of an internal organ of a subject and a storage unit for holding information for correcting characteristics intrinsic to the imaging element; and an endoscope video processor including a control unit that is connected to the endoscope, corrects a subject image, which is imaged by the imaging element on the basis of the information held in the storage unit to correct the characteristics intrinsic to the imaging device, and generates video information on the body cavity and the lumen of the internal organ of the subject.

Description

[Technical Field]

[0001] The present invention relates to an endoscope system capable of observing the interior of a body cavity or an internal organ, and a control method thereof. [Background technology]

[0002] Conventionally, an endoscopic system used for endoscopic surgery or the like has been known as an example of a medical system in the medical field, etc. Such an endoscopic system includes an endoscope and an endoscopic video processor connected to the endoscope. The endoscope includes an imaging element that captures images of the body cavity or the lumen of the internal organs of a subject, and a cable for transmitting electrical signals corresponding to the optical image of the target area of the subject captured by the imaging element. The endoscopic video processor converts the electrical signals input from the endoscope via the cable into video signals and displays them on a monitor or the like connected to the endoscopic video processor. Note that the following patent documents are prior art documents that describe technologies related to the technology described in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6622292 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in an endoscopic system, various types of endoscopes are prepared according to the type of endoscopic surgery or the like. Each of the various endoscopes prepared according to the type of endoscopic surgery or the like has its own unique characteristics that require correction when capturing an image of a subject. An operator (surgeon) operating the endoscope corrects the optical image captured through the image sensor by, for example, operating a panel of an endoscopic video processor, using a menu or the like for correcting the unique characteristics of the endoscope. This has required the operator operating the endoscope to manually correct the optical image captured through the image sensor for each of the endoscopes prepared according to the type of endoscopic surgery or the like.

[0005] The present invention has been made in consideration of the above-described circumstances, and its object is to provide a technology that reduces the effort required for correction for each endoscope in an endoscopic video processor and improves usability. [Means for solving the problem]

[0006] In order to solve the above-described problems, an endoscope system according to one aspect of the present invention includes: an endoscope including an imaging element for imaging a body cavity or an internal organ cavity of a subject, and a storage unit for storing information for correcting characteristics inherent to the imaging element; an endoscope video processor including a control unit connected to the endoscope, correcting an image of a subject captured by the image sensor based on information for correcting characteristics specific to the image sensor stored in the storage unit, and generating video information of a body cavity or an internal organ cavity of the subject; The present invention is characterized by comprising:

[0007] This allows the endoscope in the endoscopic system to store information for correcting the inherent characteristics attributable to the image sensor in memory. An endoscopic video processor connected to the endoscope can then read out the information for correcting the inherent characteristics stored in memory. The endoscopic video processor can automatically perform correction processing on the captured images for each field or frame generated at predetermined intervals based on the information regarding correction acquired from the endoscope, thereby generating a video signal. This endoscopic system can eliminate the effort required for correction for each endoscope in the endoscopic video processor, improving usability.

[0008] In another aspect of the present invention, the information for correcting the inherent characteristics of the imaging element may include position information of a defective pixel included in the imaging element, and the control unit may perform interpolation processing for the defective pixel based on pixel information of surrounding pixels including adjacent pixels adjacent to the defective pixel. The endoscopic video processor can interpolate pixel information for the defective pixel based on pixel information for the defective pixel and surrounding pixels including adjacent pixels adjacent to the defective pixel. Even for an image of a subject captured by an imaging element containing pixel defects (such as an image of a body cavity or an internal organ cavity of a subject through which an endoscope is inserted), a video signal can be generated in which pixel information corresponding to the position of the defective pixel is appropriately interpolated.

[0009] In another aspect of the present invention, the information for correcting the inherent characteristics of the imaging element may include information indicating sensitivity differences between pixels constituting the imaging element, and the control unit may perform a correction process to equalize sensitivity variations between pixels in an image of a subject captured by the imaging element based on the information indicating the sensitivity differences between the pixels constituting the imaging element. In an endoscopic video processor, correction to equalize sensitivity variations between pixels in an image is possible based on position information of pixels having relative sensitivity differences and information indicating the sensitivity differences. Even if there are relative sensitivity differences between pixels constituting the imaging element, appropriate correction to equalize sensitivity variations between pixels is possible when generating a video signal, thereby suppressing roughness such as luminance noise and color noise caused by sensitivity differences between pixels.

[0010] In another aspect of the present invention, the information for correcting the inherent characteristics of the imaging element may include information regarding a phase difference between a clock signal supplied to the imaging element and a clock signal used to output an image of the subject imaged by the imaging element, and the control unit may adjust the timing of the imaged image for each field or frame based on the information regarding the phase difference between the clock signal supplied to the imaging element and the clock signal used to output image data of the subject imaged by the imaging element. In an endoscopic video processor, based on information (time, count value, etc.) indicating the phase difference between the clock signal supplied to the imaging element and the clock signal used to output image data, timing adjustment corresponding to the phase difference is performed on the imaged image for each field or frame generated at a predetermined periodic interval, thereby generating a video signal. This can appropriately suppress the occurrence of vertical stripes in an image due to a phase difference between the clock signal supplied to the imaging element and the clock signal used to output image data.

[0011] In one aspect of the present invention, the information for correcting the inherent characteristics of the imaging element may include identification information for identifying the imaging element or an endoscope equipped with the imaging element, and the control unit may specify information related to correction of the imaging element stored in the device in association with the identification information, and perform at least one of the following processes: complementation processing for defective pixels included in the imaging element, correction processing for leveling out variations in sensitivity between pixels for an image of a subject captured by the imaging element, and timing adjustment processing for an image captured by the imaging element for each field or each frame. The endoscopic video processor may read out information for correcting the inherent characteristics of the imaging element specified by the identification information acquired from the endoscope from a memory or the like of the device, and automatically perform correction processing for an image captured for each field or each frame at a predetermined interval, thereby generating a video signal.

[0012] Another aspect of the present invention is In an endoscopic system including an endoscope having an imaging element for imaging the body cavity or the internal cavity of an internal organ of a subject, and a memory unit that stores information for correcting the inherent characteristics of the imaging element, and an endoscopic video processor connected to the endoscope, the control unit of the endoscopic video processor corrects the image of the subject captured by the imaging element based on the information for correcting the inherent characteristics of the imaging element stored in the memory unit, and generates video information of the body cavity or the internal cavity of the subject.

[0013] Even in this configuration, the endoscopic video processor can automatically perform correction processing on the captured images for each field or frame generated at a predetermined periodic interval based on the information related to correction obtained from the endoscope, and generate a video signal. This endoscopic system can reduce the effort required for correction for each endoscope in the endoscopic video processor, thereby improving usability. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a technology that reduces the effort required for correction for each endoscope in an endoscope video processor and improves usability. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram illustrating a schematic configuration of an endoscope according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating a pixel defect in an imaging element. [Figure 3] 10A and 10B are diagrams illustrating differences in sensitivity between pixels that constitute an imaging element. [Figure 4] 5A and 5B are diagrams illustrating the phase of a clock signal when image data is output. [Figure 5] 1 is a block diagram showing a schematic configuration of an endoscope system according to an embodiment of the present invention. [Figure 6] 10A and 10B are diagrams illustrating a process of complementing pixel information for a defective pixel. [Figure 7] 10 is a flowchart illustrating an example of a correction process provided by the endoscope video processor according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] [Embodiment] An endoscope system according to an embodiment of the present invention will be described in more detail below with reference to the drawings. The embodiment described below is an example of the form disclosed by the present invention, and the technical scope is not limited to the following aspect.

[0017] Fig. 1 is a diagram illustrating the schematic configuration of an endoscope 100 according to this embodiment. As shown in Fig. 1, the endoscope 100 according to this embodiment is a flexible endoscope, and includes as its components an insertion section 101, an operation section 102, a light guide plug 103, a video plug 104, and a cord 105. The light guide plug 103 and the video plug 104 are dedicated connectors for connecting the endoscope 100 to a light source device and an endoscopic video processor, respectively, not shown.

[0018] 1, insertion section 101 is a section to be inserted into a body cavity or lumen of a subject, and is provided at its tip with an illumination section (light guide) that illuminates the body cavity or the like (subject) into which the insertion is made, and an imaging element (not shown) such as a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) that converts reflected light from the body cavity or the like illuminated by the illumination light into an electrical signal as incident light. The orientation of the tip section of insertion section 101 can be changed up and down or left and right in response to an operation instruction from operation section 102.

[0019] The operation unit 102 is provided on the rear end side of the insertion unit 101, and is connected to a cord 105 having a light guide plug 103 and a video plug 104. The light guide plug 103 of the cord 105 is connected to a light source device, and the video plug 104 is connected to an endoscope video processor, which will be described later. The operation unit 102 performs an operation to emit light emitted from the light source device connected via the light guide plug 103 toward a subject. Reflected light from the subject irradiated with the irradiating light is received by an imaging element provided on the tip side of the insertion unit 101.

[0020] An imaging element provided at the tip of the insertion section 101 converts the received reflected signal into an electrical signal and outputs it to the cord 105 as pixel signals (image data) for one field or one frame sampled at predetermined time intervals (for example, 1 / 60 second or 1 / 30 second intervals). The endoscope video processor connected to the endoscope 100 via the video plug 104 generates captured images of the body cavity or internal cavity, which is the subject irradiated with the irradiation light, based on the pixel signals input through the cord 105. The captured images for each field or frame generated at predetermined periodic intervals are displayed as video signals of the target area of the subject into which the endoscope 100 is inserted on a display device such as a monitor provided in the endoscope video processor.

[0021] Incidentally, in endoscopic surgery and the like using endoscopes, various types of endoscopes are prepared. Each of the various endoscopes has its own unique characteristics that need to be corrected when acquiring an image of a subject. These unique characteristics are, for example, characteristics resulting from the image sensor provided at the tip side of the insertion section 101 of the endoscope 100, and examples of these characteristics include pixel defects during the manufacture of the image sensor, differences in sensitivity between pixels constituting the image sensor, and CLK (clock) phase when image data is output.

[0022] FIG. 2 is a diagram illustrating pixel defects in an imaging element. FIG. 2(1) illustrates an example of an imaging element having pixel defects, and FIG. 2(2) illustrates an image captured by an imaging element having pixel defects. As shown in FIGS. 2(1) and 2(2), when an object is imaged by an imaging element having pixel defects, pixel information (color information such as hue and gradation, Cy, Ye, G, M, R, G, B, etc.) corresponding to the defective pixel positions is lost. Therefore, an image of an object captured by an imaging element having pixel defects (an image of a body cavity or an internal organ cavity of a subject into which an endoscope is inserted, etc.) generates a video signal that does not include pixel information corresponding to the defective pixel positions.

[0023] FIG. 3 is a diagram illustrating the difference in sensitivity between pixels that make up an image sensor. FIG. 3 illustrates an image sensor Z2 that is configured with 9 × 7 pixels. In FIG. 3, pixel Z2a represents a pixel with a relatively low sensitivity, and pixel Z2b represents a pixel with a relatively high sensitivity. As shown in FIG. 3, there may be a relative difference in sensitivity between the pixels that make up image sensor Z2. If there is a relative difference in sensitivity between the pixels that make up the image sensor, when a video signal is generated from an image of a subject captured by the image sensor, the difference in sensitivity between the pixels will appear as roughness, such as luminance noise or color noise, in the image displayed on a monitor, etc.

[0024] FIG. 4 illustrates the phase of a clock (CLK) signal when image data is output. An image sensor scans the pixels constituting the image sensor based on a clock signal with a predetermined period, and outputs pixel signals (image data) for one field or one frame at intervals of 1 / 60 or 1 / 30 seconds. If a phase difference occurs between the clock signal supplied to the image sensor and the clock signal used to output image data, this phase difference can cause vertical stripes in an image displayed on a monitor or the like. FIG. 4(1) illustrates vertical stripes that appear in an image displayed on a monitor or the like, and FIG. 4(2) illustrates the relationship between the clock signal (CLK IN) input to the image sensor and the clock signal (DATA) used to output image data. As shown in FIG. 4(2), if a phase difference (α) occurs between the rising edge of the clock signal (CLK IN) input to the image sensor and the rising edge of the clock signal (DATA) used to output image data, vertical stripes caused by the phase difference (α) will appear in the image of the subject, as shown in image Z3 in FIG. 4(1). Although the above explanation of the phase difference between clock signals has been given taking the rising edge as an example, the same applies to the falling edge.

[0025] As described with reference to Figures 2 to 4, the endoscopic system according to this embodiment automates and simplifies the effort required for correcting the unique characteristics attributable to the imaging element of each endoscope, thereby improving usability. Specifically, the endoscope 100 of the endoscopic system according to this embodiment stores correction parameters for the unique characteristics attributable to the imaging element in its memory. The memory of the endoscope 100 stores at least information (correction parameters) for correcting the above-mentioned pixel defects of the imaging element, the difference in sensitivity between the pixels constituting the imaging element, the CLK (clock) phase when image data is output, and the like. The information for correcting the unique characteristics attributable to the imaging element of the endoscope 100 is stored in the memory in association with identification information (such as a serial number) that identifies the endoscope or the imaging element provided in the endoscope.

[0026] In the endoscopic system according to this embodiment, the endoscopic video processor acquires information (correction parameters) stored in memory from the endoscope 100 connected via the video plug 104 for correcting the inherent characteristics caused by the imaging element. The information related to correction stored in the memory of the endoscope 100 may be acquired when the video plug 104 of the endoscope 100 is attached, or when an instruction item in a menu read out via an operation panel or the like is executed. The endoscopic video processor according to this embodiment automatically corrects the inherent characteristics caused by the imaging element based on the information read out from the memory of the endoscope 100. For example, if the imaging element of the endoscope 100 contains a pixel defect, pixel information for the defective pixel is complemented using pixel information for the defective pixel. Complementing pixel information for defective pixels will be described later.

[0027] Furthermore, if there is a difference in sensitivity between pixels in the image sensor provided in the endoscope 100, the endoscopic video processor according to this embodiment performs correction to level out the variation in sensitivity between pixels. Furthermore, if there is a phase difference between the clock signal supplied to the image sensor and the clock signal used to output image data, the endoscopic video processor according to this embodiment performs processing to correct the phase difference when generating a video signal. The endoscopic system according to this embodiment eliminates the need for correction for each endoscope in the endoscopic video processor, thereby improving usability.

[0028] Fig. 5 is a block diagram showing a schematic configuration of an endoscopic system according to this embodiment. The endoscopic system 1 in Fig. 5 illustrates an endoscope 100 according to this embodiment, an endoscopic video processor 10, and a monitor 20. The endoscope 100 in Fig. 5 includes, as components, an image sensor 111 and a memory 112, which are omitted in Fig. 1. As described with reference to Fig. 1, the endoscope 100 according to this embodiment is connected to a light source device via a light guide plug 103. The endoscope 100 is connected to the endoscopic video processor 10 via a cable 105 having a video plug 104. The endoscopic video processor 10 is connected to the monitor 20 constituting the endoscopic system 1.

[0029] As already explained, the memory 112 included in the endoscope 100 holds information (correction parameters) for correcting characteristics inherent to the imaging element. Here, the memory 112 is a non-volatile storage device such as an EPROM (Erasable Programmable ROM) or a flash memory. The information related to correction held in the memory 112 includes at least information for correcting defects in pixels of the imaging element, differences in sensitivity between pixels constituting the imaging element, a CLK (clock) phase when image data is output, etc., as explained using Figs. 2 to 4 .

[0030] More specifically, information indicating the position of a defective pixel in the imaging element is held as a correction parameter to correct pixel defects in the imaging element. For example, the imaging element shown in FIG. 2 is configured with 14 pixels (horizontal) x 14 pixels (vertical). The position of the defective pixel can be expressed, for example, by two-dimensional coordinates (X, Y) where the upper left pixel of the imaging element is the coordinate origin and the horizontal direction is the X coordinate and the vertical direction is the Y coordinate. The endoscope 100 simply holds the coordinate position of the defective pixel in the imaging element 111 as a correction parameter in association with item information indicating pixel defects in the imaging element.

[0031] Furthermore, as information for correcting the difference in sensitivity between pixels, position information of pixels having a relative difference in sensitivity in the imaging element and difference information indicating the difference in sensitivity are stored as correction parameters. For example, in the imaging element Z2 shown in Fig. 3, the relative difference in sensitivity between pixel Z2b and pixel Z2c is stored together with the position information of pixel Z2b. Similarly, the relative difference in sensitivity between pixel Z2a and pixel Z2c is stored together with the position information of pixel Z2a. The endoscope 100 may store the above information as correction parameters in association with item information indicating the difference in sensitivity between pixels of the imaging element.

[0032] Furthermore, information indicating a phase difference (time, count value, etc.) is held as a correction parameter as information for correcting the CLK (clock) phase, etc., when image data is output. For example, a time and count value corresponding to the phase difference (α) between the rising edge of the clock signal (CLK IN) supplied to the imaging element in FIG. 4(2) and the rising edge of the clock signal (DATA) when image data is output are held. The endoscope 100 may hold the above information as a correction parameter in association with item information indicating the phase difference with the clock signal.

[0033] Such information is acquired in advance for each endoscope when the endoscope 100 is manufactured. Then, the manufacturer of the endoscope 100 records the acquired information (correction parameters) for correcting the inherent characteristics caused by the imaging element in the memory 112 for each endoscope. The information for correcting the inherent characteristics caused by the imaging element is stored in the memory in association with, for example, identification information (such as a serial number) that identifies the endoscope or the imaging element provided in the endoscope.

[0034] Returning to FIG. 5 , the endoscopic video processor 10 according to this embodiment is a computer including a CPU (Central Processing Unit) 12, a memory 13, and a video processing circuit 14. In the endoscopic video processor 10, the CPU 12, the memory 13, and the video processing circuit 14 constitute a control unit 11. Each of the above components may be provided in multiple locations, or some components may be omitted. The CPU 12 is a central processing unit that controls the entire endoscopic video processor 10. The CPU 12 includes an MPU (Micro-Processing Unit), a DSP (Digital Signal Processor), and the like. For example, the CPU 12 executes programs stored in memory in a work area and controls peripheral devices through the execution of the programs, thereby providing functions consistent with a predetermined purpose. The memory 13 stores programs executed by the CPU 12, data processed by the CPU, and the like. The memory 13 includes volatile storage devices such as RAM (Random Access Memory) and non-volatile storage devices such as flash memory and EPROM. The video processing circuit 14 generates a video signal of a target region of a subject into which the endoscope 100 is inserted, based on the captured image for each field or frame output from the endoscope 100. Note that some or all of the functions provided by the control unit 11, including the CPU 12 and the video processing circuit 14, may be provided by an ASIC (Application Specific Integrated Circuit), a GPU (Graphics Processing Unit), or the like. Similarly, some or all of the functions may be realized by a dedicated LSI (Large Scale Integration) such as an FPGA (Field-Programmable Gate Array), a numerical calculation processor, a vector processor, or an image processing processor, or other hardware circuit.

[0035] The endoscopic video processor 10 is equipped with a communication interface and an input / output interface (not shown). The communication interface is a communication interface for connecting the endoscopic video processor 10 to other devices such as the monitor 20. The communication interface can have an appropriate configuration depending on the connection method with other devices. The input / output interface is an interface for inputting and outputting data to and from an input / output device such as an operation panel provided in the endoscopic video processor 10. The monitor 20 is a display device including a display device such as an LCD (Liquid Crystal Display). The monitor 20 displays a video signal of the target region of the subject output from the endoscopic video processor 10 on the display device.

[0036] The endoscopic video processor 10 according to this embodiment acquires information (correction parameters) stored in a memory 112 from the endoscope 100 connected via a video plug 104 for correcting characteristics inherent to the imaging element. The information related to correction stored in the memory 112 of the endoscope 100 may be acquired when the video plug 104 is attached or when an item selected from a menu read out via an operation panel or the like is executed. The endoscopic video processor 10 then automatically corrects the characteristics inherent to the imaging element based on the information read out from the memory 112. If the imaging element of the endoscope 100 contains a pixel defect, the endoscopic video processor 10 complements the pixel information of the defective pixel using information about pixels surrounding the defective pixel for captured images for each field or frame generated at a predetermined periodic interval. Furthermore, if there is a difference in sensitivity between pixels in the imaging element of the endoscope 100, the endoscopic video processor 10 performs correction to level out the variations in sensitivity between pixels for captured images for each field or frame generated at a predetermined periodic interval. Furthermore, if there is a phase difference between the clock signal supplied to the imaging element and the clock signal used to output image data, a timing adjustment corresponding to the phase difference is made to the captured image for each field or frame generated at a predetermined periodic interval, and a video signal is generated.

[0037] FIG. 6 is a diagram illustrating the pixel information interpolation process for defective pixels. FIG. 6 illustrates an image sensor Z4 configured with 3 pixels by 3 pixels. In the image sensor Z4, pixel X represents the defective pixel, and pixels a to d represent pixels located around pixel X. The endoscopic video processor 10 according to this embodiment identifies defective pixel X in the image sensor Z4 based on the position information of the defective pixel stored in memory 112. The endoscopic video processor 10 then identifies pixels a, d, b, and c, which are adjacent to the defective pixel X on the top, bottom, left, and right sides. The endoscopic video processor 10 performs an interpolation process for the defective pixel X based on the pixel information (color information such as hue and gradation, e.g., Cy, Ye, G, M, R, G, B, etc.) of pixels a to d, which are adjacent to the defective pixel X on the top, bottom, left, and right sides. As shown in FIG. 6, the pixel information for defective pixel X is interpolated using the pixel information for pixels a to d as "(a+b+c+d) / 4." The interpolation process for defective pixels may also be performed using other known techniques. An example of a process for interpolating such defective pixels is bicubic interpolation. In bicubic interpolation, the defective pixel is interpolated based on the gradient of a cubic equation (a gradient at which color information such as hue and gradation changes) calculated from pixel information of surrounding pixels around the defective pixel position. The surrounding pixels are, for example, a pixel group of 3x3 pixels, 4x4 pixels, 5x5 pixels, etc., including adjacent pixels adjacent to the defective pixel.

[0038] (Processing flow) Fig. 7 is a flowchart showing an example of correction processing provided by the endoscopic video processor 10 according to this embodiment. This flow provides automatic correction for characteristics inherent to the image sensor 111 included in the endoscope 100. Note that the correction processing shown in Fig. 7 is performed for each field or frame of image data output from the endoscope 100 at intervals of 1 / 60 seconds or 1 / 30 seconds.

[0039] In the flowchart of FIG. 7, the process can be started, for example, when the video plug 104 of the endoscope 100 is attached to the endoscopic video processor 10. However, it may also be started when an instruction item in a menu read out via an operation panel of the endoscopic video processor 10 is executed while the endoscope 100 is connected to the endoscope 100 via the video plug 104. After the process starts, in step S101, information (correction parameters) for correcting the inherent characteristics of the image sensor stored in the memory 112 is acquired from the endoscope 100 connected via the video plug 104. The information for correcting the inherent characteristics of the image sensor includes at least position information of defective pixels included in the image sensor, information indicating the sensitivity difference between the pixels constituting the image sensor, and information regarding the phase difference between the clock signal supplied to the image sensor and the clock signal used to output image data. The CPU 12 of the endoscopic video processor 10 temporarily stores the correction information acquired from the memory 112 of the endoscope 100 in a predetermined storage area of the memory 13, and the process proceeds to step S102.

[0040] In step S102, it is determined whether or not the information regarding correction acquired from the endoscope 100 includes correction information regarding a defective pixel included in the imaging element. If the information regarding correction acquired from the endoscope 100 includes correction information regarding a defective pixel included in the imaging element (step S102, "Yes"), the process proceeds to step S103. If not (step S102, "No"), the process proceeds to step S104. In step S103, as described with reference to FIG. 6, a process of complementing pixel information for the defective pixel is performed based on pixel information for adjacent pixels adjacent to the defective pixel on the top, bottom, left, and right.

[0041] Next, in step S104, it is determined whether or not the information regarding correction acquired from the endoscope 100 includes information for correcting the sensitivity difference between the pixels that make up the image sensor. If the information regarding correction acquired from the endoscope 100 includes information for correcting the sensitivity difference between the pixels that make up the image sensor (step S104, "Yes"), the process proceeds to step S105; if not (step S104, "No"), the process proceeds to step S106. In step S105, a correction process is performed to level out the variation in sensitivity between pixels in the captured image based on the position information of pixels having relative sensitivity differences and information indicating the sensitivity differences.

[0042] Similarly, in step S106, it is determined whether the information regarding correction acquired from the endoscope 100 includes information regarding the phase difference between the clock signal supplied to the image sensor and the clock signal used to output image data. If the information regarding correction acquired from the endoscope 100 includes information regarding the phase difference between the clock signal supplied to the image sensor and the clock signal used to output image data (step S106, “Yes”), the process proceeds to step S107; if not (step S106, “No”), this routine is temporarily terminated. In step S107, based on information (time, count value, etc.) indicating the phase difference between the clock signal supplied to the image sensor and the clock signal used to output image data, timing adjustment corresponding to the phase difference is performed on the captured images for each field or frame generated at a predetermined periodic interval, and a video signal is generated. After processing in step S107, this routine is temporarily terminated.

[0043] As described above, in the endoscopic system 1 of this embodiment, the endoscope 100 can store information for correcting characteristics unique to the image sensor 111 in the memory 112. The endoscopic video processor 10 of this embodiment can acquire information for correcting characteristics unique to the endoscope 100 when the video plug 104 of the endoscope 100 is attached, or when the operator inputs an instruction via an operation panel of the endoscopic video processor 10 while the endoscope 100 is connected to the video plug 104. The endoscopic video processor 10 of this embodiment can then automatically perform correction processing on captured images for each field or frame generated at predetermined intervals based on the information related to correction acquired from the endoscope 100, thereby generating a video signal. The endoscopic system 1 of this embodiment can eliminate the effort required for correction for each endoscope in the endoscopic video processor 10, thereby improving usability.

[0044] In the endoscope system 1 of this embodiment, the endoscope 100 can hold position information of defective pixels contained in the image sensor 111 as parameters, as information for correcting characteristics inherent to the image sensor 111. As described with reference to Fig. 6, the endoscope video processor 10 can complement pixel information for a defective pixel based on pixel information for adjacent pixels adjacent to the defective pixel above, below, left, and right. According to this embodiment, even for an image of a subject captured by an image sensor containing pixel defects (an image of a body cavity or the lumen of an internal organ of a subject into which an endoscope is inserted, for example), a video signal can be generated in which pixel information corresponding to the defective pixel position has been appropriately complemented.

[0045] Furthermore, in the endoscope system 1 of this embodiment, the endoscope 100 can store, as a parameter, information indicating the sensitivity difference between the pixels constituting the image sensor 111 as information for correcting the inherent characteristics attributable to the image sensor 111. The endoscopic video processor 10 can perform correction to level out the sensitivity variation between pixels in a captured image based on the position information of pixels having a relative sensitivity difference and information indicating the sensitivity difference. According to this embodiment, even if there is a relative sensitivity difference between the pixels constituting the image sensor, appropriate correction can be performed to level out the sensitivity variation between pixels when generating a video signal, thereby suppressing roughness such as luminance noise and color noise caused by the sensitivity difference between pixels.

[0046] Furthermore, in the endoscope system 1 of this embodiment, the endoscope 100 can store, as a parameter, information regarding the phase difference between the clock signal supplied to the image sensor and the clock signal used to output image data, as information for correcting characteristics inherent to the image sensor 111. The endoscopic video processor 10 can perform timing adjustments corresponding to the phase difference on captured images for each field or frame generated at predetermined intervals, based on information (time, count value, etc.) indicating the phase difference between the clock signal supplied to the image sensor and the clock signal used to output image data, thereby generating a video signal. According to this embodiment, the occurrence of vertical stripes in an image caused by the phase difference between the clock signal supplied to the image sensor and the clock signal used to output image data can be appropriately suppressed.

[0047] (Variation) In the endoscopic system 1 described in the embodiment, the memory 112 of the endoscope 100 is described as holding information for correcting the inherent characteristics of the imaging element 111 in association with identification information (such as a serial number) that identifies the endoscope or the imaging element 111 provided in the endoscope. The information held in the memory 112 of the endoscope 100 can also be limited to the identification information (such as a serial number) that identifies the endoscope or the imaging element 111 provided in the endoscope. The information for correcting the inherent characteristics of the imaging element 111 in association with the identification information can also be held in the endoscopic video processor 10.

[0048] That is, in the endoscopic system 1 of the modified example, the endoscope 100 holds, in the memory 112, identification information (such as a serial number) that identifies the endoscope or the imaging element 111 provided in the endoscope, as information for correcting characteristics inherent to the imaging element 111. Furthermore, the endoscopic video processor 10 of the endoscopic system 1 of the modified example stores, in the memory 13, information for correcting characteristics inherent to the imaging element 111 that corresponds to the identification information held in the memory 112 of the endoscope 100, in association with the identification information. The memory 13 stores the information for correcting characteristics inherent to the imaging element 111 in association with the identification information (such as a serial number) that identifies the endoscope 100 or the imaging element 111 provided in the endoscope.

[0049] 7, the endoscopic video processor 10 of the modified example acquires, from the endoscope 100 connected via the video plug 104, identification information (such as a serial number) that identifies the endoscope or the image sensor 111 provided in the endoscope, which is stored in the memory 112, as information for correcting inherent characteristics.The endoscopic video processor 10 of the modified example then refers to the memory 13, identifies information for correcting inherent characteristics of the image sensor 111 that is associated with the acquired identification information (such as a serial number), and executes the processes of steps S102 to S107 based on the identified information for correcting inherent characteristics.

[0050] Even in the modified form, the endoscopic video processor can automatically correct the inherent characteristics attributable to the imaging element provided in the endoscope based on the identification information acquired as information related to correction acquired from the endoscope, and generate a video signal from the captured images for each field or frame generated at a predetermined periodic interval. Even in the modified form, the effort required for correction for each endoscope in the endoscopic video processor can be reduced, thereby improving usability.

[0051] (others) The above-described embodiment is merely an example, and the disclosure of the present embodiment may be appropriately modified and implemented without departing from the spirit thereof. The processes and means described in this disclosure may be freely combined and implemented as long as no technical contradiction occurs.

[0052] Furthermore, a process described as being performed by one device may be shared and executed by multiple devices. Alternatively, a process described as being performed by different devices may be executed by a single device. In an endoscope system, the hardware configuration for realizing each function can be flexibly changed. [Explanation of symbols]

[0053] 1: Endoscope system 10: Endoscope video processor 11: Control unit 12:CPU 13: Memory 14: Video processing circuit 20: Monitor 100: Endoscope 101: Insertion section 102:Operation unit 103: Light guide plug 104:Video plug 105: Cable 111: Image sensor 112: Memory

Claims

1. an endoscope including an imaging element for imaging a body cavity or an internal organ cavity of a subject, and a storage unit for storing information for correcting characteristics inherent to the imaging element; an endoscope video processor including a control unit connected to the endoscope, correcting an image of the subject captured by the imaging element based on information for correcting characteristics inherent to the imaging element stored in the storage unit, and generating video information of a body cavity or an internal organ cavity of the subject, the information for correcting the inherent characteristics of the imaging element includes information regarding a phase difference between a rising edge of a clock signal supplied to the imaging element and a rising edge of the clock signal when an image of the subject imaged by the imaging element is output, or information regarding a phase difference between a falling edge of the clock signal supplied to the imaging element and a falling edge of the clock signal when an image of the subject imaged by the imaging element is output, the control unit adjusts timing for the captured image for each field or each frame based on information regarding a phase difference between a rising edge of a clock signal supplied to the image sensor and a rising edge of a clock signal when the captured image of the subject captured by the image sensor is output, or a phase difference between a falling edge of a clock signal supplied to the image sensor and a falling edge of a clock signal when the captured image of the subject captured by the image sensor is output. An endoscope system characterized by:

2. the information for correcting the inherent characteristics of the imaging element includes position information of defective pixels included in the imaging element; The endoscope system according to claim 1 , wherein the control unit performs interpolation processing on the defective pixel based on pixel information of surrounding pixels including adjacent pixels adjacent to the defective pixel.

3. The information for correcting the inherent characteristics of the imaging element includes position information of pixels having relative sensitivity differences in the imaging element and difference information indicating the sensitivity differences. is information indicating the sensitivity difference between pixels, 2. The endoscope system according to claim 1, wherein the control unit performs correction processing to level out variations in sensitivity between pixels in the image of the subject captured by the imaging element, based on information indicating the sensitivity difference between pixels constituting the imaging element, the information including position information of pixels having relative sensitivity differences in the imaging element and difference information indicating the sensitivity difference.

4. the information for correcting the inherent characteristics of the imaging element includes identification information for identifying the imaging element or an endoscope equipped with the imaging element; The endoscope system according to claim 1, characterized in that the control unit identifies information regarding correction of the endoscope that is associated with the identification information and stored in the device itself, and further performs a complementation process for defective pixels included in the imaging element based on position information of the defective pixels included in the imaging element as the information regarding correction of the endoscope, and a correction process for leveling out variations in sensitivity between pixels in the image of the subject imaged by the imaging element based on position information of pixels in the imaging element that have relative sensitivity differences and difference information indicating the sensitivity differences as the information regarding correction of the endoscope.

5. An endoscope system including an endoscope having an image pickup element for picking up an image of a body cavity or an internal organ of a subject, and a storage unit storing information for correcting characteristics inherent to the image pickup element, and an endoscope video processor having a control unit connected to the endoscope, correcting an image of the subject picked up by the image pickup element based on the information for correcting characteristics inherent to the image pickup element stored in the storage unit, and generating video information of the body cavity or internal organ of the subject, the information for correcting the inherent characteristics of the imaging element includes identification information for identifying the imaging element or an endoscope equipped with the imaging element; a control method comprising: identifying information relating to correction of the endoscope stored in the device in association with the identification information; and performing timing adjustment processing for an image captured by the imaging element for each field or frame based on information relating to the correction of the endoscope, the information being a phase difference between the rising edge of a clock signal supplied to the imaging element and the rising edge of the clock signal when an image of the subject captured by the imaging element is output, or a phase difference between the falling edge of a clock signal supplied to the imaging element and the falling edge of the clock signal when an image of the subject captured by the imaging element is output.

Images