JP2010069244A - Inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device capable of accurately performing the inspection of noise in the image processing of an endoscopic system. <P>SOLUTION: The inspection device 70 of the endoscopic system 1 includes a holding part 71 for holding the leading end of a scope 10 in a fixed state, a light guide member 73 for guiding the light emitted from a light source 31 used for the illumination through the scope 10 and a diffusion part 75 provided at a position opposed to the leading end of the scope 10 when the scope 10 is attached to the holding part 71 and diffusing the light from the light source 31 guided through the light guide member 73 to radiate the same toward the scope 10. The irradiation region of the light in the diffusion part 73 is larger than the region imaged by the scope 10 in the diffusion part 73. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an inspection apparatus, and more particularly to an apparatus for performing a noise inspection in image processing of an endoscope system.

  In an endoscope system having a scope equipped with an image sensor, an image processing characteristic of the endoscope system such as white balance is inspected at the time of development or the like. In such an inspection, a chart (for example, a white balance chart) suitable for the inspection is imaged, and a value necessary for the inspection is measured from the obtained image signal or the like.

Patent Document 1 discloses an inspection device (measuring container) for inspecting image processing characteristics by imaging a color chart or the like provided inside with a scope.
Japanese Patent Laid-Open No. 05-137693

  However, in the apparatus of Patent Document 1, since reflected light of light emitted from the scope is imaged, whiteout occurs due to reflection of the emitted light on the chart. For this reason, it is not possible to accurately perform inspection of image processing characteristics, particularly noise inspection in image processing.

  Accordingly, an object of the present invention is to provide an inspection apparatus that can accurately perform noise inspection in image processing of an endoscope system.

  An inspection apparatus for an endoscope system according to the present invention includes a holding unit that holds the scope in a fixed state, a light guide member that guides light emitted from a light source unit used for illumination via the scope, When the scope is attached to the holding unit, a diffusion unit that is provided at a position facing the tip of the scope and diffuses light from the light source unit guided through the light guide member and irradiates the scope. The light irradiation area in the diffusion unit is larger than the area imaged by the scope in the diffusion part.

  Since the light emitted from the diffusing unit toward the scope has a uniform intensity distribution by the diffusing unit, the scope can capture light with no unevenness. Since the light source of the light source unit used for normal observation in the endoscope system is used as the light source of light having a uniform intensity distribution generated in the diffusion unit, the problem of cost increase due to the preparation of a separate light source device, and inspection In order to improve accuracy, there is no problem of difficulty in matching the light source conditions during inspection with those during normal observation. The configuration of the diffusing unit may be a backlight system that diffuses light from the back surface or a sidelight system that diffuses light from the side surface.

  Preferably, the diffusing unit includes a reflecting unit to which an end portion of the light guide member is attached and configured by a part of an integrating sphere, and a diffusing plate disposed between the reflecting unit and the holding unit. The diffusion plate irradiates the scope with light emitted from the end portion of the light guide member and diffused between the reflection portion and the diffusion plate.

  Light emitted from the light source part and emitted from the light guide member is spatially integrated by repeating diffuse reflection in a space surrounded by the reflection part and the diffusion plate. As a result, the diffusion plate is Irradiate the scope with white light having almost the same intensity distribution in any part of the lens.

  Preferably, the image signal obtained by imaging the light emitted from the light source unit through the light guide member and irradiated by the diffusion unit with a scope is used for noise inspection of the endoscope system. used.

  Since a noise inspection is performed based on an image signal obtained by imaging light without unevenness, it is possible to accurately grasp the degree of noise generation while avoiding confusion between unevenness and noise.

  More preferably, the holding unit includes a chart holding unit in which a first inspection chart that transmits light emitted from the diffusion plate is detachable between the diffusion plate and the scope attached to the holding unit, One inspection chart is any one of a white balance chart, a resolution chart, a gray scale chart, and a color chart. Light from the light source section is guided through the light guide member and reflected by the diffusing section. The image signal obtained by imaging the transmitted light in the first inspection chart with the scope while being irradiated on the first inspection chart is used for inspection of the image processing characteristics of the endoscope system.

  By using these charts, it is possible to inspect other image processing characteristics such as white balance while the scope is held by the holding unit using the inspection apparatus. In particular, when the inspection chart is of a transmissive type, inspection using light through the light guide member can be performed following the noise inspection.

  Preferably, the holding portion includes a chart holding portion in which a second inspection chart that does not transmit light from the diffusion plate can be attached and detached between the diffusion plate and the scope attached to the holding portion. The inspection chart is any one of a white balance chart, a resolution chart, a gray scale chart, and a color chart, and light from the light source unit is guided through the light guide of the scope and applied to the second inspection chart. In this state, the image signal obtained by imaging the reflected light in the second inspection chart with the scope is used for inspection of image processing characteristics of the endoscope system.

  By using these charts, it is possible to inspect other image processing characteristics such as white balance while the scope is held by the holding unit using the inspection apparatus.

  As described above, according to the present invention, it is possible to provide an inspection apparatus that can accurately perform noise inspection in image processing of an endoscope system.

  Hereinafter, the configuration of the endoscope system according to the present embodiment will be described with reference to the drawings. The endoscope system 1 according to the present embodiment includes a scope 10, a processor 30, and a monitor 50 (during normal observation, refer to FIG. 1). Further, as will be described later, when the endoscope system 1 is developed or manufactured, an inspection apparatus 70 and a noise meter 90 are also used to inspect image processing characteristics. The scope 10 includes a light guide 11 such as an optical fiber cable, an objective optical system 13 including an objective lens and a visibility correction filter, an imaging unit 14 including an imaging element such as a CCD, a video signal processing unit 15, and the scope 10 and the processor 30. Signal line 16 used for transmission of electrical signals and image signals between the two.

  The processor 30 includes a light source unit 31, a video signal processing unit 33, and a control unit 35 that controls each unit of the processor 30. In the processor 30, subsequent image processing for generating an image (video signal) that can be displayed on the monitor 50 is performed on the image signal acquired by the scope 10 and subjected to the previous image processing in the video signal processing unit 15.

  A monitor 50 is connected to the processor 30. The monitor 50 is a display unit that displays an image that has been subjected to image processing by the processor 30 and that conforms to a predetermined video signal standard. In addition to the monitor 50, the processor 30 may be connected to an external storage device that records image data processed by the processor 30, a printer that outputs (prints out) an image, and the like.

  During normal observation, one end of the light guide 11 is disposed at a position for receiving emitted light from the light source 31 of the processor 30 (see FIG. 1). The light emitted from the light source unit 31 is irradiated from the distal end portion of the scope 10 toward the object to be observed through the light guide 11. The light source unit 31 includes a light source 31a that emits light and a diaphragm 31b. The amount of light emitted from the light source 31a to the object to be observed through the light guide 11 is adjusted by the opening of the diaphragm 31b.

  Reflected light from the object to be observed enters the image sensor of the image capturing unit 14 via the objective optical system 13. The image sensor photoelectrically converts the incident light and outputs an image signal. The image signal output from the imaging unit 14 is subjected to the preceding image processing such as YC separation, white balance adjustment, and color correction in the video signal processing unit 15, and the video signal processing unit of the processor 30 through the signal line 16. 33 is output. In the processor 30, the video signal processing unit 33 performs subsequent image processing to obtain a video signal that can be output by the monitor 50.

  In the present embodiment, when the scope 10 or the processor 30 is developed or manufactured, an inspection apparatus 70 is used to inspect image processing characteristics in the endoscope system 1 (see FIGS. 2, 4, and 5). As an inspection of image processing characteristics in the endoscope system 1, a first inspection (noise inspection, see FIG. 2) and a second inspection (see FIG. 4, FIG. 5) are performed. The inspection apparatus 70 is not used during normal observation of the endoscope system 1 (see FIG. 1). The inspection apparatus 70 includes a holding portion 71 that holds the distal end portion of the scope 10 in a fixed state during the first and second inspections, a light guide member 73, and a diffusion portion 75.

  The holding unit 71 includes a main body 71a, a fixing base 71b, and a chart slot 71c (see FIGS. 2, 4, and 5). The main body 71a is a housing that surrounds the distal end portion of the scope 10 in a light-shielded state. The fixing base 71b provided in the main body 71a is a member that fixes the distal end portion of the scope 10 at a predetermined position, faces the diffusion plate 75b, and keeps the distance between the imaging unit 14 and the diffusion plate 75b constant. In particular, in consideration of the fact that the objective lens of the objective optical system 13 used in the scope 10 has a relatively wide angle, and in order to ensure the shielding of the distal end of the scope 10, the distal end of the scope 10 is used. Is preferably fixed at a position as close to the diffusion plate 75b as possible. In addition, the fixing base 71b fixes the distal end portion of the scope 10 so that the region of the diffusion plate 75b that is imaged by the scope 10 is disposed within the light irradiation region of the diffusion plate 75b.

  The chart slot 71c holds the inspection chart 77 in a detachable manner. During the first inspection, the inspection chart 77 is not used and is removed from the chart slot 71c (see FIG. 2). For this reason, during the first inspection, the insertion slot of the chart slot 71c is shielded from light.

  The light guide member 73 is an optical fiber cable that guides the light emitted from the light source unit 31 to the diffusion unit 75, and it is desirable to use an optical fiber cable equivalent to the optical fiber cable used for the light guide 11 of the scope 10. At the time of the first inspection, one end of the light guide member 73 is disposed at a position for receiving the emitted light from the light source unit 31 (see FIG. 2). At this time, the light guide 11 is removed from the position where the light emitted from the light source unit 31 is received.

  The diffusion unit 75 includes a reflection unit 75a and a diffusion plate 75b. The reflecting portion 75a is constituted by a part of an integrating sphere (semi-integrating sphere) in which a diffuse reflective white paint is applied to the inner wall. However, the shape is not limited to a semi-integrating sphere, and may be another integrating sphere shape. The reflection surface of the reflection portion 75a is configured by a substantially complete diffuse reflection surface (R (λ) = 1). The reflection part 75a is provided with a port (opening), and the other side of the light guide member 73 is connected to the port so that light from the light guide member 73 is emitted toward the inside of the reflection part 75a or toward the diffusion plate 75b. The end of is attached. The location and number of ports in the reflecting portion 75a are not limited to those shown in FIG.

  The diffuser plate 75 b is a plate-like diffuser disposed between the reflecting portion 75 a and the holding portion 71. The light from the light source unit 31 and emitted from the port of the reflection unit 75a through the light guide member 73 repeatedly diffuses and reflects spatially in the space surrounded by the reflection unit 75a and the diffusion plate 75b. As a result, the diffuser plate 75b irradiates white light having substantially the same intensity distribution toward the scope 10 in any part of the diffuser plate 75b. In order to obtain white light having a uniform intensity distribution in the entire region imaged by the scope 10 in the diffusing plate 75b, the inner diameter of the reflecting portion 75a and the diffusing plate 75b is attached to the fixed base 71b of the holding portion 71 by the scope 10. In this state, it is set larger than the diameter of the region imaged by the scope 10 in the diffusion plate 75b. That is, the light irradiation area on the diffusion plate 75b is larger than the area captured by the scope 10 on the diffusion plate 75b.

  During the first inspection, the light emitted from the light source unit 31 is irradiated from the diffusion unit 75 toward the scope 10 via the light guide member 73. At this time, light is not emitted through the light guide 11. Note that the amount of light emitted from the light source 31a to the diffusing unit 75 via the light guide member 73 is adjusted to be a predetermined amount of light for the first inspection by the opening of the diaphragm 31b.

  The light emitted from the diffusion plate 75b enters the image sensor of the imaging unit 14 via the objective optical system 13. The image sensor photoelectrically converts the incident light and outputs an image signal. The image signal output from the imaging unit 14 is subjected to the preceding image processing such as YC separation, white balance adjustment, and color correction in the video signal processing unit 15, and the video signal processing unit of the processor 30 through the signal line 16. 33 is output. In the processor 30, the video signal processing unit 33 performs subsequent image processing to generate a video signal. At the time of the first inspection, the noise meter 90 is connected to the video signal output terminal of the processor 30.

  The control unit 35 of the processor 30 calculates the luminance value Y of the entire image based on the Y signal separated in the video signal processing unit 15, and the luminance value Y corresponds to a predetermined light quantity for the first inspection. The opening degree of the diaphragm 31b is adjusted so that the luminance value y1 will be obtained. However, the calculation of the luminance value Y is detected by the noise meter 90 or performed by another device connected to the processor 30, and the adjustment of the opening degree of the diaphragm 31b corresponding to the inspection luminance value y1 is performed manually or An automatic form may be used.

  After the adjustment of the light amount, that is, the adjustment of the opening of the diaphragm 31b is completed, the video signal output from the processor 30 is used for noise measurement. Specifically, the noise meter 90 connected to the processor 30 calculates a luminance value for each pixel in the video signal, and measures the difference between the brightest luminance value and the darkest luminance value (luminance amplitude). . The video signal output from the processor 30 at the time of the first inspection is obtained by imaging light in which white light having a uniform intensity distribution is irradiated from the diffusion plate 75b to the entire region imaged by the scope 10. Therefore, when the amount of noise generation in the image processing of the endoscope system 1 is small, the difference between the brightest luminance value and the darkest luminance value is hardly seen, and when the amount of noise generation is large, the difference occurs. . For this reason, it is possible to accurately grasp the degree of noise generation in the image processing of the endoscope system 1 based on the magnitude of the difference.

  The degree of noise removal in the video signal processing unit 33 is set based on the first inspection result (degree of noise generation). In addition, it is fed back to the development of the endoscope system 1 and is used to determine design values and the like of each part in the endoscope system 1.

  In addition, a mode in which noise is detected based on a difference in luminance in a video signal obtained by irradiating light reflected through the light guide 11 onto a reflective white chart and imaging the reflected light of the white chart. Conceivable. However, in this case, unevenness (spots) in the white chart becomes a luminance difference, and there is a possibility that it is erroneously determined that there is noise. Even when the white chart itself has almost no unevenness, whiteout due to reflection of light emitted from the light guide 11 becomes unevenness on the white chart and may be erroneously determined as having noise. . On the other hand, in the present embodiment, since the first inspection (noise inspection) is performed based on the difference in luminance of the video signal obtained by imaging the light having a uniform intensity distribution in the diffusion unit 75, unevenness is caused. It is possible to accurately grasp the degree of noise generation by avoiding confusion with noise.

  Further, as a light source of light having a uniform intensity distribution generated in the diffusing unit 75, a mode in which a light source device different from the light source unit 31 used for normal observation in the endoscope system 1 is used is also conceivable. However, in this case, there are a problem of cost increase by separately preparing a light source device, and a problem that it becomes difficult to match the conditions of the light source during the first inspection with those during normal observation in order to improve the inspection accuracy. .

  In the present embodiment, the configuration of the diffusing unit 75 is a backlight system that diffuses light from the back surface (opposite side of the holding unit 71), that is, the intensity distribution is uniform in the reflecting unit 75a provided on the back surface of the diffusing plate 75b. The configuration of the diffuser 75 is a sidelight type that diffuses the light from the side, that is, the light from the light guide member 73 is emitted to the side of the diffuser 75b, and the diffuser 75b It may be a form that generates light with a uniform intensity distribution.

  Next, the procedure for performing the first inspection will be described with reference to the flowchart of FIG. In step S11, the scope 10 is attached to the fixed base 71b. In step S12, the light source 31a is turned on. In step S <b> 13, the light emitted from the light source unit 31 reaches the diffusion unit 75 via the light guide member 73, and is irradiated from the diffusion plate 75 b toward the holding unit 71. The imaging unit 14 images the light emitted from the diffusion unit 75 and outputs an image signal. The image signal is subjected to preceding image processing in the video signal processing unit 15 and subsequent image processing in the video signal processing unit 33 to generate a video signal.

  In step S <b> 14, the control unit 35 calculates the luminance value Y of the entire image based on the Y signal separated by the video signal processing unit 15. In step S15, the control unit 35 determines whether or not the calculated luminance value Y is equal to the inspection luminance value y1. If not equal, the process proceeds to step S16, and if equal, the process proceeds to step S17.

  In step S16, the control unit 35 adjusts the opening of the diaphragm 31b so that the luminance value Y becomes equal to the inspection luminance value y1, and the process returns to step 14. In step S17, noise measurement is performed.

  Next, a second inspection (measurement of white balance, resolution, gradation, color reproducibility, etc. of the endoscope system 1), which is an inspection of image processing characteristics different from the first inspection, will be described. The inspection apparatus 70 is used not only for the first inspection of the endoscope system 1 but also for the second inspection (see FIGS. 4 and 5). The second inspection is performed with the inspection chart 77 attached to the inspection apparatus 70. The inspection chart 77 is a chart used for measuring white balance, resolution, gradation, color reproducibility, and the like of the endoscope system 1 and is attached to the diffusion plate 75b and the holding unit 71 during the second inspection. It is attached to a chart slot 71 c provided between the scope 10 and the scope 10. At the time of the second inspection, the monitor 50 is connected to the video signal output terminal of the processor 30.

  Specific examples of the inspection chart 77 include a white balance chart, a resolution chart, a gray scale chart, and a color chart. The white balance chart is used for measuring the white balance of the endoscope system 1, the resolution chart is used for measuring the resolution of the endoscope system 1, and the gray scale chart is used for measuring the gradation of the endoscope system 1. The color chart is used for measuring the color reproducibility of the endoscope system 1. When each measurement is performed in the second inspection, the corresponding inspection chart 77 is attached to the chart slot 71c.

  The inspection chart 77 may be a transmission type that transmits light from the diffusion plate 75b or a reflection type that does not transmit light. When the inspection chart 77 is a transmissive type (see FIG. 4), the light guide member 73 is connected to the light source unit 31, and the light emitted from the light source unit 31 is reflected by the light guide member 73, the reflection unit 75a, The imaging unit 14 images the transmitted light of the inspection chart 77 that is irradiated to the opposite side of the scope 10 of the inspection chart 77 through the diffusion plate 75b. However, when measuring white balance, it is necessary to prepare a transmission chart having spectral transmission characteristics equivalent to the spectral reflection characteristics of the reflection type white balance chart. When the inspection chart 77 is a reflection type (see FIG. 5), the light guide 11 is connected to the light source unit 31, and the light emitted from the light source unit 31 passes through the light guide 11 of the scope 10. The side of the inspection chart 77 facing the scope 10 is irradiated, and the imaging unit 14 images the reflected light of the light.

  The image signal output from the imaging unit 14 is subjected to the preceding image processing such as YC separation, white balance adjustment, and color correction in the video signal processing unit 15, and the video signal processing unit of the processor 30 through the signal line 16. 33 is output. In the processor 30, the video signal processing unit 33 performs subsequent image processing to obtain a video signal that can be output by the monitor 50. An inspection chart image is displayed on the monitor 50. For example, when a color chart is used in the second inspection, the inspection chart image displayed on the monitor 50 is measured using a spectral radiance meter or the like. Note that the measurement is not limited to the spectral radiance meter, and is not limited to the measurement based on the image displayed on the monitor 50. A configuration in which a measurement device is connected to the video signal output terminal of the processor 30 and the luminance and chromaticity for each color are measured using the measurement device may be employed.

  Based on the second inspection result, a setting value such as white balance in the video signal processing unit 33 is determined. In addition, it is fed back to the development of the endoscope system 1 and is used to determine design values and the like of each part in the endoscope system 1.

  Accordingly, it is possible to perform inspection of other image processing characteristics such as white balance in a state where the scope 10 is held by the holding unit 71 using the inspection apparatus 70 that performs the first inspection (noise inspection). In particular, when the inspection chart is a transmissive type, inspection can be performed using light via the light guide member 73 following the first inspection.

  In the state where the light guide 11 is not connected to the processor 20 during the first and second inspections, such as the scope 10 having a configuration in which the light guide 11 and the signal line 16 are integrally formed, the signal in the scope 10 It is also conceivable that the line 16 cannot be directly connected to the processor 20. In this case, the extension cable 101 that maintains the connection of the signal line 16 between the scope 10 and the processor 30, the light guide receiving portion 102 that blocks the connection of the light guide 11 to the processor 30, and the processor 30 of the light guide member 73. By providing the intermediate connection device 100 having the light guide member receiving portion 103 for maintaining the connection between the scope 10 and the processor 30, the problem is solved (see FIG. 6).

It is a lineblock diagram of an endoscope system at the time of normal observation in this embodiment. It is a lineblock diagram of the endoscope system and inspection device at the time of the 1st inspection. It is a flowchart which shows the procedure of a 1st test | inspection. It is a block diagram of an endoscope system and an inspection apparatus at the time of a second inspection when a transmission type inspection chart is used. It is a block diagram of an endoscope system and an inspection apparatus at the time of a second inspection when a reflection type inspection chart is used. FIG. 3 is a configuration diagram of an endoscope system when an intermediate connection device is provided between a scope and a processor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Endoscope system 10 Scope 11 Light guide 13 Objective optical system 14 Imaging part 15 Video signal processing part 16 Signal line 30 Processor 31 Light source part 31a Light source 31b Aperture 33 Video signal processing part 35 Control part 50 Monitor 70 Inspection apparatus 71 Holding part 71a body 71b fixing base 71c chart slot (chart holding part)
73 Light guiding member 75 Diffusing portion 75a Reflecting portion 75b Diffusing plate 90 Noise meter 100 Intermediate connection device 101 Extension cable 102 Light guide receiving portion 103 Light guiding member receiving portion

Claims (5)

A holding part that holds the scope tip in a fixed state; and
A light guide member for guiding light emitted from a light source unit used for illumination through the scope;
When the scope is attached to the holding unit, the scope is provided at a position facing the tip of the scope, diffuses light from the light source unit guided through the light guide member, and toward the scope. An irradiating diffuser,
An inspection apparatus for an endoscope system, wherein a light irradiation region in the diffusion unit is larger than a region captured by the scope in the diffusion unit. The diffusing portion includes a reflecting portion to which an end portion of the light guide member is attached and configured by a part of an integrating sphere, and a diffusing plate disposed between the reflecting portion and the holding portion. And
The said diffusion plate irradiates the light which was radiate | emitted from the edge part of the said light guide member and was diffused between the said reflection part and the said diffusion plate toward the said scope. Inspection device.   The image signal obtained by imaging the light from the light source unit, which is guided through the light guide member and irradiated by the diffusion unit, with the scope is used for noise inspection of the endoscope system. The inspection apparatus according to claim 2, wherein the inspection apparatus is used. The holding unit has a chart holding unit in which a first inspection chart that transmits light emitted from the diffusion plate is detachable between the diffusion plate and the scope attached to the holding unit;
The first inspection chart is any one of a white balance chart, a resolution chart, a gray scale chart, and a color chart,
Light from the light source part is guided through the light guide member, reflected by the diffusion part, and transmitted through the first inspection chart from the diffuser plate to the first inspection chart. The inspection apparatus according to claim 3, wherein an image signal obtained by imaging light with the scope is used for inspection of image processing characteristics of the endoscope system. The holding portion has a chart holding portion in which a second inspection chart that does not transmit light from the diffusion plate is detachable between the diffusion plate and the scope attached to the holding portion;
The second inspection chart is any one of a white balance chart, a resolution chart, a gray scale chart, and a color chart,
Obtained by imaging the reflected light on the second inspection chart with the scope in a state where the light from the light source unit is guided through the light guide of the scope and irradiated on the second inspection chart. The inspection apparatus according to claim 3, wherein the image signal is used for inspection of image processing characteristics of the endoscope system.

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