JP5959331B2 - Endoscope device - Google Patents

Description

  The present invention relates to an endoscope apparatus, and more particularly to an endoscope apparatus that can obtain an image with less aberration by cutting out an image and controlling driving of an image sensor.

  2. Description of the Related Art Conventionally, endoscope apparatuses include endoscope apparatuses in which different types of optical adapters are detachable from an insertion portion. Such an endoscope apparatus generally has an aberration such as a distortion aberration according to the characteristics of an optical lens provided in the optical adapter or an image sensor disposed at the tip of the insertion portion.

  In general, when aberration correction is performed, aberration correction is performed by providing an aberration correction lens in the optical adapter. If the aberration correction lens cannot completely correct the aberration, or if the optical adapter is not provided with the aberration correction lens, the image processing circuit corrects the aberration.

  When aberration correction is performed by the image processing circuit, for example, as disclosed in Patent Document 1 and Patent Document 2, the aberration correction is performed using a correction data table corresponding to the correction characteristics of the optical lens to be mounted. ing.

JP 2004-64710 A JP 2007-189361 A

  However, when aberration correction is performed using a lens, an aberration correction lens is required, and the number of lenses increases. When the number of aberration correction lenses increases, the length of the hard tip portion becomes longer, and the insertion property of the insertion portion becomes worse.

  When performing aberration correction by the image processing circuit, the image processing circuit requires an aberration detection block and an aberration correction processing block. Since the aberration correction processing includes arithmetic processing, the arithmetic processing circuit becomes larger as the accuracy of aberration correction increases. Further, the larger the image data to be corrected, the longer the time required for correction.

  Therefore, depending on the processing capability of the aberration correction processing block and the resolution of the image to be processed, the subject may not be displayed on the display unit in real time.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an endoscope apparatus that can acquire an image with little aberration in a circuit scale and can be acquired in real time.

  An endoscope apparatus according to an aspect of the present invention includes an imaging element having a predetermined effective pixel number, a display unit having an effective pixel number smaller than the predetermined effective pixel number of the imaging element, and imaging with the imaging element. An aberration detection unit that detects an aberration area based on luminance information and edge information from an image signal generated from the captured image signal, and the smallest aberration area based on the aberration detection result detected by the aberration detection unit And an image cutout unit that cuts out an image that matches the effective pixel region of the display unit from the effective pixel region of the image sensor.

  According to the endoscope apparatus of the present invention, an image with little aberration can be acquired in real time with a small circuit scale.

It is a figure which shows the structure of the endoscope apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the image clipping process in an image clipping part. It is a flowchart which shows the example of the flow of an image cut-out process. 10 is a flowchart illustrating an example of a processing flow when the optical adapter 2 is removed from the insertion unit 3. 10 is a flowchart illustrating an example of a flow of processing when the optical adapter 2 is attached to the insertion unit 3. It is a figure which shows the structure of the endoscope apparatus which concerns on 2nd Embodiment. It is a figure for demonstrating the change process of the drive position of CCD. It is a flowchart which shows the example of the flow of a change process of the drive position of CCD.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)

  First, the configuration of the endoscope apparatus according to the first embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a diagram illustrating a configuration of an endoscope apparatus according to the first embodiment.

  As shown in FIG. 1, an endoscope apparatus 1 includes an insertion portion 3 having an optical adapter 2 that is detachable at a distal end portion, and an imaging mounted on the insertion portion 3, to which the insertion portion 3 is detachably connected. It has a main body section 4 that performs signal processing on the element, and a display section 5 that displays an image captured by the image sensor as an endoscopic image when a video signal output from the main body section 4 is input.

  The optical adapter 2 is provided with an optical lens 6 corresponding to the type. There are various types of the optical adapter 2 such as a direct-view type, a side-view type, a wide-angle type, and a narrow-angle type. Further, the distal end portion of the insertion portion 3 also has a small diameter type, a large diameter type, and the like, and the optical adapter 2 of the optimum type is attached to the distal end portion of the insertion portion 3 according to the use and situation of the endoscopy. .

  As described above, there are various combinations of the optical adapter 2 and the distal end portion of the insertion portion 3, and the aberration may be increased depending on the combination. In addition, the position of the aberration may change due to individual variations of the optical adapter 2 and the distal end of the insertion portion 3.

  The insertion portion 3 is elongated and flexible so that it can be inserted into an inspection target such as a pipe, and is configured to be detachable from the main body portion 4 by a connector 7 provided at an end portion. Further, an objective lens 8 is attached to the distal end portion of the insertion portion 3, and for example, a charge coupled device (hereinafter abbreviated as CCD) 9 is arranged as an imaging device at the image forming position.

  In the present embodiment, the CCD 9 has a high resolution, for example, a resolution (the number of effective pixels) sufficiently higher than the resolution of the display unit 5, and the display unit 5 has a lower resolution than the CCD 9, for example, XGA (1024 × 768 pixels) (the number of effective pixels).

  The main body 4 includes an analog front end (hereinafter abbreviated as AFE) 11, a camera control unit (hereinafter abbreviated as CCU) 12, and a control unit 13. The main body 4 is configured so that a recording medium 14 is detachable. The recording medium 14 records an image output from the control unit 13 as a still image or a moving image.

  The control unit 13 controls the entire endoscope apparatus 1 and detects the attachment of the optical adapter 2. Further, the control unit 13 controls the output of an image to the display unit 5 and the recording medium 14.

  The CCU 12 includes an image processing unit 15, a timing generator (hereinafter abbreviated as TG) 16, an aberration detection unit 17, and an image cutout unit 18.

  The CCD 9 performs photoelectric conversion on the return light from the inspection object imaged on the imaging surface based on a CCD driving signal from the TG 16 described later, and outputs the obtained imaging signal. This imaging signal is input to the AFE 11 provided in the main body unit 4 through a signal cable inserted through the insertion unit 3.

  The AFE 11 includes a CDS circuit, an A / D circuit, and the like. The input imaging signal is subjected to correlated double sampling (CDS) processing in the CDS circuit portion in accordance with the timing signal from the TG 16 and converted into a digital signal in the A / D circuit portion. This digital signal is input to the image processing unit 15.

  The image processing unit 15 detects a synchronization signal in the input digital signal and outputs it to the TG 16, and performs predetermined image processing on the input digital signal to generate an image signal to be displayed on the display unit 5. And output to the aberration detector 17.

  The TG 16 generates a timing signal to be output to the CDS circuit and a CCD drive signal for driving the CCD 9 based on the synchronization signal from the image processing unit 15, and outputs them to the AFE 11 and the CCD 9, respectively.

  The aberration detector 17 detects in which part of the image the aberration is generated based on the luminance information and the edge information from the image signal output from the image processor 15. As a method of detecting aberrations, a method of correcting from aberration information of a lens, or a method of obtaining aberration information by observing a subject capable of recognizing the state of the subject, such as a lattice chart when there is no lens correction information, is possible. is there. The aberration detection unit 17 outputs the aberration detection result thus detected to the image cutout unit 18 together with the image signal.

  The image cutout unit 18 cuts out an image based on the aberration detection result so that the aberration area is minimized. More specifically, the image cutout unit 18 cuts out an image that matches the effective pixel region of the display unit 5 from the effective pixel region of the CCD 9 so that the aberration area is minimized based on the aberration detection result.

  For example, the image cutout unit 18 compares the top, bottom, left, and right of the screen from the aberration detection result, and shifts the image cutout position to the right if the aberration is large on the left side. Similarly, if the aberration is large in the upward direction, the image clipping unit 18 shifts the image clipping position downward. In this case, the image cut-out size is set in accordance with the resolution of the display unit 5. In addition, the image cutout unit 18 cuts out the image so as to be an approximately central portion of the output image of the CCD 9 as an initial (default) cutout position.

  FIG. 2 is a diagram for explaining the image cutout process in the image cutout unit.

  As illustrated in FIG. 2A, the image cutout unit 18 cuts out the initial cutout position 20 so as to be approximately the center of the output image 21 of the CCD 9.

  As shown in FIG. 2B, the aberration detector 17 has an area 22 having aberration on the right side (toward the drawing) of the screen among the top, bottom, left and right of the image (specifically, the image at the cutout position 20). 2 is detected, the image cutout unit 18 shifts the image cutout position 20 to the left side of the drawing as shown in FIG. Cut out. This changed cutout position is set as a cutout position 20a.

  As shown in FIG. 2C, if the area 22 with aberration is large and the area 22 with aberration exists at the cutout position 20a even when the cutout is performed with the resolution of the display unit 5, the display is performed. While maintaining the resolution aspect ratio of the unit 5, the display may be displayed on the display unit 5 by performing a scaling process with a reduced resolution.

  In addition, as a configuration in which the CCU 12 includes an aberration correction unit, the aberration correction of the area 22 where the aberration of the cutout image is present may be performed. In this case, since the area 22 having the aberration of the clipped image in FIG. 2C is smaller than the area 22 having the aberration of the clipped image in FIG. 2B, the aberration correction processing time can be shortened. .

  Next, the operation of the endoscope apparatus 1 configured as described above will be described.

  FIG. 3 is a flowchart illustrating an example of the flow of the image cutout process.

  First, when the system of the endoscope apparatus 1 is activated (step S1), it is determined whether or not the optical adapter 2 is attached to the insertion portion 3 (step S2). When it determines with the optical adapter 2 not being attached to the insertion part 3, it becomes NO, returns to step S2, and repeats the same process. On the other hand, if it is determined that the optical adapter 2 is attached to the insertion portion 3, the determination is YES, and the CCD 9 is driven by the CCD drive signal from the TG 16 of the CCU 12 (step S3). Next, the aberration detection unit 17 detects the aberration area of the output image of the CCD 9 (step S4). An image is cut out by the image cutout unit 18 so that the aberration area on the screen is minimized (step S5). And an image is displayed on the display part 5 from the control part 13 (step S6), and a process is complete | finished.

  Next, processing when the optical adapter 2 is removed from the insertion portion 3 will be described.

  FIG. 4 is a flowchart showing an example of the flow of processing when the optical adapter 2 is removed from the insertion portion 3.

  First, it is determined whether or not the optical adapter 2 has been removed from the insertion portion 3 (step S11). If it is determined that the optical adapter 2 has not been removed from the insertion portion 3, the determination is NO, the process returns to step S11, and the same processing is repeated. On the other hand, if it is determined that the optical adapter 2 has been removed from the insertion portion 3, the determination is YES, the image cutout position is returned to the initial (default) cutout position (step S12), and the process is terminated.

  Next, processing when the optical adapter 2 is attached to the insertion portion 3 will be described.

  FIG. 5 is a flowchart showing an example of the flow of processing when the optical adapter 2 is attached to the insertion portion 3. In FIG. 5, the same processes as those in FIG.

  First, it is determined whether or not the optical adapter 2 is attached to the insertion portion 3 (step S21). When it determines with the optical adapter 2 not being attached to the insertion part 3, it becomes NO, returns to step S21, and repeats the same process. On the other hand, when it determines with the optical adapter 2 having been attached to the insertion part 3, it becomes YES and progresses to step S3. Steps S <b> 3 to S <b> 6 are the same as in FIG. 3, the aberration area corresponding to the newly attached optical adapter 2 is detected, and the image cutout position is changed.

  The replacement of the insertion unit 3 cannot be performed while the system is running. Therefore, when replacing the insertion unit 3, the system is temporarily stopped, then the insertion unit 3 is replaced, and the process shown in FIG. 3 is performed again. Will do. Then, the endoscope apparatus 1 newly detects aberration due to the combination of the replaced insertion portion 3 and the optical adapter 2 and changes the cutout position of the image.

  Through the above processing, an image with less aberration can be displayed on the display unit 5 regardless of the combination of the optical adapter 2 and the insertion unit 3.

  As described above, the endoscope apparatus 1 detects the aberration area of the image displayed on the display unit 5 by the aberration detection unit 17 and reduces the aberration area by the image cutout unit 18 from the output image of the CCD 9. The image was cut out. As a result, since it is not necessary to provide an aberration correction circuit for correcting aberrations, the circuit scale can be reduced. In addition, since aberration correction processing is not required by the aberration correction circuit, an image with little aberration can be obtained in real time.

  Therefore, according to the endoscope apparatus of the present embodiment, an image with less aberration can be acquired in real time with a reduced circuit scale.

Furthermore, the endoscope apparatus 1 according to the present embodiment eliminates the need to provide a lens for aberration correction in the optical adapter 2, so that the length of the distal end hard portion can be shortened and the insertability of the insertion portion 3 is improved. Can do. Further, since shading can be avoided in the same manner, a shading correction circuit is not necessary, and the circuit scale can be further reduced.
(Second Embodiment)

  Next, a second embodiment will be described.

  FIG. 6 is a diagram illustrating a configuration of an endoscope apparatus according to the second embodiment. In FIG. 6, the same components as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 6, the endoscope apparatus 1a is configured using an image processing unit 15a, a TG 16a, and an aberration detection unit 17a, respectively, instead of the image processing unit 15, TG 16, and the aberration detection unit 17 of FIG. .

  The TG 16 a outputs to the CCD 9 a CCD drive signal for driving the vertical drive position (readout position) of the CCD 9 in accordance with the resolution of the display unit 5. The image signal picked up by the CCD 9 is subjected to predetermined image processing by the image processing unit 15a and then input to the aberration detection unit 17a.

  The aberration detection unit 17a detects in which part of the image the aberration is generated from the input image signal, outputs the detected aberration detection result to the image cutout unit 18, and feeds it back to the image processing unit 15a. .

  The image processing unit 15a controls the TG 16a to change the vertical drive position of the CCD 9 so that the aberration area on the screen is minimized based on the fed back aberration detection result.

  The TG 16a as a drive position control unit outputs a CCD drive signal in which the drive position in the vertical direction of the CCD 9 is changed to the CCD 9 under the control of the image processing unit 15a.

  FIG. 7 is a diagram for explaining the change processing of the drive position of the CCD.

  As shown in FIG. 7A, the TG 16 a drives the initial driving position 23 of the CCD 9 in accordance with the resolution of the display unit 5. The driving position 23 at this time is set to a substantially central portion of the output image 21 when the CCD 9 captures an image with the original resolution.

  When the aberration detection unit 17a detects that there is an area 22 with aberration on the upper side of the screen (toward the drawing), as shown in FIG. 7B, the image processing unit 15a From the aberration detection result of the aberration detector 17, the TG 16a is controlled so as to shift the vertical drive position 23 of the CCD 9 downward as shown in FIG. 7C. The changed vertical driving position is defined as a driving position 23a.

  The CCD 9 can control the driving position 23 in the vertical direction, but cannot control the driving position in the horizontal direction, and all pixels in one line are read out. Therefore, when there is an area 22 with aberration on the left and right of the image, the left and right cutout positions are changed by the image cutout unit 18 as in the first embodiment.

  For example, as shown in FIG. 7B, when there is an area 22 having an aberration on the right side of the image as shown in the drawing, the image clipping unit 18 selects the image clipping position as shown in FIG. The image is cut out by shifting 20 to the left side of the drawing (cutout position 20a).

  Note that when a CMOS is used instead of the CCD 9 as the image sensor, the horizontal driving position can also be controlled. Therefore, the vertical and horizontal driving positions of the CMOS may be controlled by the TG 16a based on the aberration detection result.

  Next, the operation of the endoscope apparatus 1a configured as described above will be described.

  FIG. 8 is a flowchart showing an example of the flow of processing for changing the CCD drive position. In FIG. 8, the same processes as those in FIG.

  First, when it is determined in step S2 that the optical adapter 2 is attached, the CCD 9 is driven with a resolution that matches the resolution of the display unit 5 by the TG 16a of the CCU 12 (step S31). In step S4, when the aberration area is detected by the aberration detector 17a, the vertical drive position of the CCD 9 is changed by the TG 16a so that the aberration area on the screen is minimized (step S32). Next, the image cutout unit 18 determines the image cutout position in the horizontal direction so that the aberration area on the screen is minimized, and the image is cut out (step S33). Finally, in step S6, an image is displayed on the display unit 5 from the control unit 13, and the process ends.

  As described above, the endoscope apparatus 1a drives the drive position (reading position) in the vertical direction of the CCD 9 in accordance with the resolution of the display unit 5, and when there is an aberration area in the vertical direction of the image, the CCD 9 The drive position (readout position) in the vertical direction is changed by the TG 16a. As a result, the drive position of the CCD 9 can be changed in an area with little aberration and in accordance with the resolution of the display unit 5, so that the frequency of the CCD drive signal of the CCD 9 can be lowered.

  Therefore, according to the endoscope apparatus of the present embodiment, the same effect as that of the first embodiment can be obtained, and the frequency of the CCD drive signal of the CCD 9 can be lowered, thereby reducing power consumption and length. Time drive is possible.

  Note that the steps in the flowchart in this specification may be executed in a different order for each execution by changing the execution order and executing a plurality of steps at the same time as long as it does not contradict its nature.

  The present invention is not limited to the above-described embodiments and modifications, and various changes and modifications can be made without departing from the scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Endoscope apparatus, 2 ... Optical adapter, 3 ... Insertion part, 4 ... Main part, 5 ... Display part, 6 ... Optical lens, 7 ... Connector, 8 ... Objective lens, 9 ... CCD, 11 ... AFE, 12 ... CCU, 13 ... control section, 14 ... recording medium, 15, 15a ... image processing section, 16, 16a ... TG, 17, 17a ... aberration detection section.

Claims (5)

An image sensor having a predetermined number of effective pixels;
A display unit having an effective pixel number smaller than the predetermined effective pixel number of the imaging element;
An aberration detector that detects an aberration area based on luminance information and edge information from an image signal generated from an imaging signal imaged by the imaging element;
Based on the aberration detection result detected by the aberration detection unit, an image cutout unit that cuts out an image that matches the effective pixel region of the display unit from the effective pixel region of the image sensor so that the aberration area is minimized,
An endoscope apparatus comprising:   The drive position control unit that controls the drive position of the image sensor so as to minimize the aberration area based on the aberration detection result detected by the aberration detection unit. Endoscopic device. The image sensor is a CCD,
The endoscope apparatus according to claim 2, wherein the drive position control unit controls the drive position of the CCD in the vertical direction so that the aberration area is minimized.   2. The endoscope according to claim 1, wherein when the aberration area is present in the cut out image, an image of a region where the aberration area does not exist is scaled according to an effective pixel region of the display unit. apparatus.   The endoscope apparatus according to claim 1, wherein when the aberration area is present in the cut out image, aberration correction is performed on an image in a region where the aberration area is present.

Images