JP2010075378A - Inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection system for accurately obtaining the luminance of each pixel in an image signal obtained in an endoscope system. <P>SOLUTION: The inspection system includes an inspection device comprising a holder part for holding the distal end of a scope in the fixed state, and a reflection part disposed at a position facing the distal end of the scope when the scope is fixed to the holder part. The inner wall of the reflection part is hemispherical to reflect the light emitted from a light source used for illumination and irradiated via the scope on the inner wall. The inspection system also has a measuring device for calculating the luminance of each pixel in the image signal obtained by the scope capturing the incident light reflected from the reflection part and via an object optical system of the scope. The scope is attached to the holder part and the positional relation between the scope and the reflection part is set so that the optical axis of the object optical system is perpendicular to the plane including a circle constituting an opening of the hemisphere of the reflection part and that the optical axis passes through the center of the circle. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an inspection system, and more particularly to a system for inspecting illumination-related members of an endoscope system.

In an endoscope system having a scope on which an image sensor is mounted, an inspection relating to the characteristics of the endoscope system is performed during development. For example, inspection of image processing characteristics of an endoscope system such as white balance is performed. 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. For example, Patent Document 1 discloses an inspection device (measuring container) for inspecting image processing characteristics by imaging a color chart or the like provided therein with a scope.
Japanese Patent Laid-Open No. 05-137693

  However, when an image of a flat chart is captured as in the apparatus of Patent Document 1, a distance difference between the chart and the objective optical system is generated between the central portion and the peripheral portion of the chart, and a difference in reach of reflected light is reached. As a result, peripheral brightness dimming occurs, and the luminance value distribution for each pixel in the image signal obtained by imaging cannot be obtained accurately. For this reason, it is impossible to correctly inspect illumination-related members such as the light source unit, the light guide, and the light distribution lens.

  Accordingly, an object of the present invention is to provide an inspection system that accurately obtains a luminance value for each pixel in an image signal obtained by an endoscope system.

  The inspection system of the endoscope system according to the present invention is provided at a position facing the distal end portion of the scope when the scope is fixed to the holding portion, the holding portion that holds the scope distal end portion in a fixed state, The inner wall has a spherical crown shape, the inspection device has a reflection unit that reflects the light emitted from the light source unit used for illumination through the scope and irradiated through the scope, and the reflection unit reflects the light. A measuring device that calculates a luminance value for each pixel in an image signal obtained by imaging the light incident through the objective optical system of the scope with the scope, and the optical axis of the objective optical system However, the scope is attached to the holding part so as to be perpendicular to the plane including the circle constituting the opening of the spherical crown of the reflecting part and through the center of the circle, and the positional relationship between the scope and the reflecting part is set. The

  The reflected light of the light emitted from the scope is imaged using an inspection device including a spherical crown-shaped reflecting portion that shows a part of the sphere. Since there is almost no difference in the arrival distance of the reflected light from any part of the reflecting part to the objective optical system, the reflected light can be imaged in the absence of peripheral dimming based on the difference in the arrival distance. The luminance value for each pixel in the obtained image signal can be accurately calculated.

  Preferably, the measuring device calculates a peak luminance value in the image signal and a pixel position corresponding to the peak luminance value.

  It is possible to accurately calculate the peak luminance value on the image obtained by imaging, the pixel position corresponding to the peak luminance value, and the degree of ambient light attenuation.

  More preferably, the peak luminance value and the pixel position corresponding to the peak luminance value are guided by the light source unit, a light guide for guiding the light emitted from the light source unit to the distal end of the scope, and the light guide emitted from the light source unit. It is used to identify at least one defect of the light distribution lens that irradiates the reflected light toward the reflecting portion.

  Based on these calculation results, it is possible to identify defects in the illumination-related members including the light source unit, the light guide, and the light distribution lens.

  Preferably, the scope is attached to the holding unit so that the distance from the objective optical system and the part that reflects the light irradiated from the light distribution lens of the reflecting unit to the objective optical system is equal. In addition, the positional relationship between the scope and the reflecting portion is set.

  It is possible to make the difference in the arrival distance of the reflected light from the reflection portion to the objective optical system the smallest, and it is possible to image the reflected light with the least amount of peripheral light reduction based on the difference in the arrival distance.

  As described above, according to the present invention, it is possible to provide an inspection system that accurately obtains a luminance value for each pixel in an image signal obtained by 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 measurement apparatus 90 are attached to the endoscope system 1 in order to inspect image processing characteristics. The scope 10 includes a light guide 11 such as an optical fiber cable, a light distribution lens 12, 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, and a video signal processing unit 15. .

  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 during normal observation. 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.

  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 and the light distribution lens 12. 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 and the light distribution lens 12 is adjusted by the opening of the diaphragm 31b. The

  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 is output to the video signal processing unit 33 of the processor 30. 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 and the processor 30 are developed and manufactured, the light source unit 31, the light guide 11, and the light distribution lens 12 in the endoscope system 1 are included using the inspection device 70 and the measurement device 90. A brightness inspection is performed to identify defects in lighting-related members (see FIG. 2). The inspection device 70 and the measurement device 90 are not used during normal observation of the endoscope system 1 (see FIG. 1). The inspection device 70 includes a holding unit 71 that holds the distal end portion of the scope 10 in a fixed state during a brightness inspection, and a reflection unit that reflects the light emitted from the light distribution lens 12 of the scope 10 toward the objective optical system 13. 75. The measuring device 90 is a PC that calculates a luminance value for each pixel based on the video signal output from the processor 30.

  The holding portion 71 is a member that fixes the distal end portion of the scope 10 at a predetermined position and keeps the distance between the objective optical system 13 and the reflecting portion 75 constant. The reflection part 75 is comprised by the hemisphere body by which the diffuse reflection white coating material was apply | coated to the inner wall. The reflection surface of the reflection unit 75 is configured by a substantially complete diffuse reflection surface (R (λ) = 1). At the time of the brightness inspection, the distal end portion of the scope 10 faces the inner wall of the reflecting portion 75, the optical axis LX of the objective optical system 13 is perpendicular to a plane including a circle that forms the hemispherical opening of the reflecting portion 75, and The scope 10 is attached to the holding portion 71 so that the positional relationship passes through the center of the circle, and the positional relationship between the scope 10 and the reflecting portion 75 is set.

  In particular, the objective optical system 13 is arranged in the vicinity of the center of the circle so that the distance from any portion of the region that reflects the light irradiated from the light distribution lens 12 of the reflecting portion 75 to the objective optical system 13 becomes equal. It is desirable to be done.

  At the time of the brightness inspection, the light emitted from the light source unit 31 is emitted toward the inner wall of the reflection unit 75 via the light guide 11 and the light distribution lens 12. Depending on the purpose of the brightness inspection, an automatic dimming mode for automatically adjusting the opening of the diaphragm 31b or a manual dimming mode for manually setting is set. When the reflection portion 75 is imaged by automatic light control as the brightness inspection, when evaluating the light diffusion state in the illumination-related member, the automatic light control mode is set. As a brightness test, when evaluating the degree of light diffusion in the illumination-related member when the reflection unit 75 is imaged with a specific brightness setting, the manual brightness control mode corresponds to the specific brightness. A throttle 31b is set to the opening.

  Reflected light from the reflection unit 75 is incident on 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 is output to the video signal processing unit 33 of the processor 30. In the processor 30, the video signal processing unit 33 performs subsequent image processing to generate a video signal. At the time of the brightness inspection, the measuring device 90 is connected to the video signal output terminal of the processor 30.

  The video signal output from the processor 30 is used for brightness inspection. Specifically, the measurement device 90 connected to the processor 30 calculates the luminance value for each pixel in the video signal, and based on this, the highest luminance peak luminance value and the pixel position corresponding to the peak luminance value , And the surrounding dimming degree are calculated.

  When illumination-related devices such as the light source unit 31, the light guide 11, and the light distribution lens 12 are normally mounted and image an object to be observed having a uniform reflectance distribution, The image signal is designed so that the luminance value is a predetermined value and the peak luminance value, that is, the specific position of the image is brightest. If a failure occurs in any part of the lighting-related device, such as the mounting position is shifted, the pixel position corresponding to the peak luminance value may be displaced from a specific position, or the peak luminance value may be reduced. Because it happens, grasp the value of the peak luminance value and the corresponding pixel position, etc., and perform a brightness inspection to identify the malfunction of the lighting related device by comparing it with the peak luminance value assumed in the normal state and the corresponding pixel position Is possible.

  However, it is necessary to accurately obtain the luminance value for each pixel in the image obtained by imaging such as the peak luminance value. When a planar reflection part having a uniform reflectance distribution is imaged, a difference appears in the distance reaching the objective optical system 13 from an arbitrary point on the reflection part. Accordingly, there is a possibility that the peak luminance value and the pixel position corresponding to the peak luminance value cannot be obtained correctly. Therefore, in order to eliminate the difference in the arrival distance of the reflected light to the objective optical system 13, the imaging of the objective optical system 13 having a wide-angle lens in a state where the reflecting portion is arranged far from the objective optical system 13 and arranged far away. In order to cover the area, it is necessary to prepare a wide reflection portion, which increases the size of the apparatus.

  In the present embodiment, the inspection device 70 including the hemispherical reflection unit 75 is used to reflect light irradiated through the light guide 11 and the light distribution lens 12 and the reflected light is imaged by the imaging unit 14. . Since there is almost no difference in the arrival distance of the reflected light to the objective optical system 13 in the reflection section 75, it becomes possible to pick up substantially uniform white light on one side with no peripheral dimming based on the difference in arrival distance. It is possible to accurately calculate the luminance value for each pixel in the obtained image signal. Based on the luminance value for each pixel, the peak luminance value, the pixel position corresponding to the peak luminance value, and the surrounding dimming degree are accurately calculated, and based on these calculation results, the light source unit 31, the light guide 11, and It is possible to accurately identify the malfunction of the illumination-related member including the light distribution lens 12.

  In the present embodiment, the inner wall of the reflecting part 75 is formed in a hemispherical shape, and the distance between the objective optical system 13 and any part of the inner wall of the reflecting part 75 can be made substantially equal. Therefore, the reflecting part 75 is unnecessarily enlarged. It is not necessary to increase the size of the inspection apparatus 70.

  The inner wall of the reflecting portion 75 is not limited to a hemispherical shape, and may be a spherical crown shape that is a part of a sphere. However, it is desirable to have a size that covers the irradiation area from the light distribution lens 12 and the light receiving area of the objective optical system 13.

  Next, a procedure for attaching the scope 10 to the inspection apparatus 70 and acquiring an image (video signal) for brightness inspection will be described with reference to the flowchart of FIG. In step S <b> 11, the distal end portion of the scope 10 is attached to the holding portion 71. In step S12, the reflector 75 is attached to a predetermined position. The positional relationship between the scope 10 and the inspection apparatus 70 is determined by steps S11 and S12. In addition, if the holding part 71 and the reflection part 75 are prepared in a fixed state and a positioning member that guides the position where the scope 10 is attached to the holding part 71 is provided, step S11 is performed. The operation in step S12 can also be completed.

  In step S13, the light source 31a is turned on. Depending on the purpose of the brightness inspection, an automatic dimming mode for automatically adjusting the opening of the diaphragm 31b or a manual dimming mode for manually setting is set. In step S <b> 14, the light emitted from the light source unit 31 is irradiated toward the inner wall of the reflection unit 75 via the light guide 11 and the light distribution lens 12. The imaging unit 14 captures the reflected light from the reflection 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.

  Next, the procedure for specifying the peak luminance value and the pixel position corresponding to the peak luminance value based on the video signal will be described with reference to the flowchart of FIG. In step S31, the video signal generated in step S14 of FIG. In step S32, the luminance value Y of one pixel in the video signal is calculated. In step S33, it is determined whether or not the luminance value Y calculated this time is larger than the peak luminance value Ymax calculated up to the previous time. If larger, the peak luminance value Ymax is updated to the current luminance value Y in step S34, and the process proceeds to step S35. If not, the process proceeds to step S35.

  In step S35, it is determined whether or not the luminance value Y has been calculated for all the pixels. If not, the process returns to step S32 to calculate the luminance value Y for other pixels, and steps S32 to S34 are repeated. When the luminance values Y for all the pixels have been calculated, the process ends, and the peak luminance value Ymax and the pixel position corresponding to the peak luminance value Ymax are determined. Further, based on the luminance value Y for each pixel, a luminance value distribution is calculated, and the degree of ambient light attenuation is calculated.

It is a lineblock diagram of an endoscope system at the time of normal observation in this embodiment. It is a block diagram of an endoscope system, an inspection device, and a measurement device at the time of brightness inspection. It is a flowchart which shows the procedure which acquires a video signal. It is a flowchart which shows the procedure which calculates a peak luminance value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Endoscope system 10 Scope 11 Light guide 13 Objective optical system 14 Imaging part 15 Image | video signal processing part 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 75 Reflection part 90 Measuring device

Claims (4)

A holding part that holds the scope tip in a fixed state; and when the scope is fixed to the holding part, the scope is provided at a position facing the scope tip, and an inner wall has a spherical crown shape, An inspection apparatus having a reflection part that reflects the light emitted from the light source part used for illumination through the scope and irradiated through the scope at the inner wall;
A measuring device that calculates a luminance value for each pixel in an image signal obtained by imaging the light reflected by the reflecting unit and incident through the objective optical system of the scope with the scope; ,
The scope is attached to the holding unit so that the optical axis of the objective optical system is perpendicular to a plane including a circle constituting the opening of the crown of the reflecting unit and passes through the center of the circle; and An inspection system for an endoscope system, wherein a positional relationship between the scope and the reflector is set.   The inspection system according to claim 1, wherein the measurement device calculates a peak luminance value in the image signal and a pixel position corresponding to the peak luminance value.   The peak luminance value and the pixel position corresponding to the peak luminance value are determined by the light source unit, a light guide that guides light emitted from the light source unit to the distal end of the scope, and the light guide emitted from the light source unit. The inspection system according to claim 2, wherein the inspection system is used to identify at least one defect of the light distribution lens that irradiates the light guided in the step toward the reflection portion. The scope is attached to the holding unit so that the distance from the objective optical system and the part of the reflective part that reflects the light irradiated from the light distribution lens to the objective optical system is equal. The inspection system according to claim 1, wherein a positional relationship between the scope and the reflection unit is set.

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