JP2005115149A - Flange-back measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flange-back measuring instrument capable of measuring the flange-back of the body of a digital camera with high precision. <P>SOLUTION: The flange-back measuring instrument is equipped with a white light source 11, a splitting member 13 which splits the light from the white light source into two, and guides light L<SB>1</SB>to a 1st optical path and light L<SB>2</SB>to a 2nd optical path, a movable member 14 which is arranged movably along the 1st optical path and reflects the light L<SB>1</SB>, and a fixed member 15 which is fixedly arranged in the 2nd optical path, holds the camera body 20, and has a fitting reference surface 15A capable of coming into contact with a flange 21A to guide the light L<SB>2</SB>to an imaging element 22; and reflected light L<SB>3</SB>from the movable member and reflected light L<SB>4</SB>from the imaging element are put together to detect the position of the movable member when a maximum light quantity signal of white interference light appears and then the distance from the flange to the imaging element is calculated based upon the distance from the fitting reference surface to the reference point of the 2nd optical path and the distance from the reference point of the 1st optical path corresponding to the reference point to the detection position obtained by the detection means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flange back measuring device for measuring the flange back of a body of a digital camera with interchangeable lenses.

  As is well known, in an interchangeable lens digital camera, the distance from the lens flange to the focal plane of the lens (that is, the flange back of the lens) and the distance from the body flange to the light receiving surface of the image sensor (that is, the flange of the body). The lens and the body are manufactured so that the back is equal. This is to make the focal plane of the lens coincide with the light receiving surface of the image sensor when the lens and the body are integrated by bringing the flanges into contact with each other.

  Incidentally, in the body of a general digital camera, various optical components (for example, an infrared cut filter, a low-pass filter, etc.) are arranged on the optical axis closer to the lens than the image sensor. For this reason, the flange back of the body described above corresponds not to a physical distance from the flange to the light receiving surface of the image sensor, but to an optical distance considering the thickness and refractive index of each optical component.

By the way, an apparatus (for example, see Non-Patent Document 1) for measuring a flange back of a lens is conventionally known. Further, adjustment of the flange back of the body (that is, position adjustment of the image sensor in the optical axis direction) is performed using a lens adjusted using this device. This is an adjustment for making the light receiving surface of the image sensor coincide with the focal plane of the lens (that is, making the flange back of the body equal to the flange back of the lens). Briefly, this is performed by projecting a chart (for example, Siemens Star) on the light receiving surface of the image sensor through a lens and observing the output of the image sensor while adjusting the position of the image sensor.
"Flange back measuring instrument FBM-1 catalog", Pearl Optics Co., Ltd., 2003

In recent years, the number of pixels of an image sensor has been increased, and the pixels have been miniaturized. For this reason, a lens for a digital camera is required to have a low F number in order to capture a large amount of light. Since the depth of focus is reduced by lowering the F number of the lens, it is necessary to accurately determine the position of the light receiving surface of the image sensor.
However, even if the apparatus of Non-Patent Document 1 described above is used, the imaging element cannot be positioned with high accuracy (positioning accuracy is about several tens of μm). Therefore, it is desired to measure the flange back itself of the body with high accuracy and position the image sensor based on the result. However, since the various optical components described above are arranged in the body of the digital camera, the flange back of the body cannot be measured easily. Also, an apparatus for measuring the flange back of the body has not been proposed yet.

  An object of the present invention is to provide a flange back measuring device capable of measuring the flange back of the body of a digital camera with high accuracy.

  The invention according to claim 1 includes a white light source, a split member that splits the light from the white light source into two, guides one light to the first optical path, and guides the other light to the second optical path; A movable member that is movably disposed along one optical path, reflects the one light from the split member, and is fixedly disposed on the second optical path, and holds the camera body to be measured, and the camera A fixed member that has a mounting reference surface that can come into contact with a flange of the body, guides the other light from the divided member to an image sensor housed in the camera body, reflected light from the movable member, and the Detecting means for detecting a position of the movable member when a maximum light amount signal of white interference fringes appears by combining with reflected light from the imaging element of the camera body; and the second optical path from the mounting reference plane of the fixed member Predetermined Based on the distance to the quasi-point and the distance from the reference point of the first optical path corresponding to the reference point to the detection position by the detection means, the distance from the flange of the camera body to the image sensor is calculated. And a calculating means.

  According to a second aspect of the present invention, in the flange back measuring apparatus according to the first aspect, the detection means is the movable member when the maximum light quantity signal of the white interference fringes appears in at least three places in a predetermined visual field region. The calculation means calculates the inclination of the image sensor relative to the flange in addition to calculating the distance from the flange to the image sensor.

  According to a third aspect of the present invention, in the flange back measuring device according to the first or second aspect, the fixing member has a flange that can contact the mounting reference plane instead of the camera body, The surface defining the reference point of the second optical path can hold a calibration member arranged at a predetermined distance from the flange, and the detection means holds the calibration member on the fixed member. In the state, the position of the movable member when the maximum light amount signal of the white interference fringe appears by the combination of the reflected light from the movable member and the reflected light from the specified surface of the calibration member, the position of the first optical path It is detected as a reference point.

  According to the present invention, the flange back of the body of a digital camera can be measured with high accuracy.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIGS. 1 and 2, the flange back measuring apparatus 10 of the present embodiment includes a white light source 11, a collimator 12, a beam splitter 13, a reference substrate 14, a mount 15, an imaging lens 16, The diaphragm 17, the photodetector 18, and a control unit (not shown) are configured. FIG. 1 shows a state in which a camera body 20 to be measured is attached to a mount 15, and a part of the camera body 20 is cut away. FIG. 2 shows a state in which a calibration member 30 is attached to the mount 15 instead of the camera body 20.

In the flange back measuring apparatus 10, light from the white light source 11 (light having a wide spectral width) enters the beam splitter 13 via the collimator 12. The beam splitter 13 divides the incident light L ₀ into two, guides one light L ₁ to the first optical path on which the reference substrate 14 is disposed, and directs the other light L ₂ to the second optical path on which the mount 15 is disposed. Lead (split member).
The reference substrate 14 is fixed on a stage (not shown) movable along the optical axis of the first optical path, and reflects the light L ₁ from the beam splitter 13 (movable member). The reference substrate 14 is a flat substrate made of glass with a wedge shape, guide the reflected light L ₃ at the surface 14A along a first optical path, so as divert the reflected light at the back surface 14B of the first optical path ing. Therefore, it is possible to avoid unnecessary interference with the reflected light of the reflected light L ₃ and the back 14B of the surface 14A. Furthermore, the reference substrate 14 can also finely adjust the angle (tilt state) of the surface 14A with respect to the optical axis of the first optical path. On the other hand, the mount 15 is fixedly disposed in the second optical path, and holds the camera body 20 of FIG. 1 or the calibration member 30 of FIG. 2 (fixing member).

  Here, the camera body 20 will be described. The camera body 20 is a body of an interchangeable lens digital camera, has a mount 21 and an image sensor 22, and the surface of the mount 21 is a flange 21 </ b> A. The flange 21 </ b> A also functions as a mounting surface to the mount 15 of the flange back measuring device 10. Various optical components (here, an infrared cut filter and a low-pass filter) are arranged on the lens side of the image sensor 22. In FIG. 1, these various optical components are collectively shown as an optical component 19. Description of other components is omitted. The image sensor 22 is, for example, a CCD image sensor or a CMOS image sensor. The digital camera is a digital still camera that can shoot still images.

As shown in FIG. 1, the optical component 19 </ b> S is disposed between the beam splitter 13 and the reference substrate 14 in the first optical path when the camera body 20 is attached. The optical component 19S is a reference member having the same configuration as the optical component 19 described above.
The flange back of the body measured by the flange back measuring apparatus 10 of the present embodiment is not the physical distance C from the flange 21A of the mount 21 of the camera body 20 to the light receiving surface 22A of the image sensor 22, but the optical component 19 The optical distance in consideration of the thickness and refractive index of each optical component. If this distance is equal to the flange back of the lens, the focal plane of the lens of the digital camera and the light receiving surface 22A of the image sensor 22 can be matched. Further, in the flange back measuring apparatus 10 of the present embodiment, the angle (tilt state) of the light receiving surface 22A of the image sensor 22 with respect to the flange 21A is also measured. The measuring operation by the flange back measuring apparatus 10 will be described later.

  Next, the calibration member 30 (FIG. 2) will be described. The calibration member 30 includes a support member 31 and a reference substrate 32, and the front end surface of the support member 31 is a flange 31 </ b> A to the mount 15 of the flange back measuring device 10. The reference substrate 32 is a flat substrate made of glass, and has a surface 32 </ b> A having substantially the same size as the light receiving surface 22 </ b> A of the image sensor 22 in the camera body 20. Further, the surface 32A of the reference substrate 32 is a surface for defining the reference point of the second optical path, and is arranged at a predetermined distance D from the flange 31A of the support member 31. This distance D corresponds to, for example, the design value of the physical distance C in the camera body 20 and is known. The flange 31A of the calibration member 30 and the surface 32A of the reference substrate 32 are substantially parallel.

Since the camera body 20 and the calibration member 30 are configured as described above, the mount 15 that holds one of them has an attachment reference surface 15A that can contact the flange 21A of the camera body 20 or the flange 31A of the calibration member 30. Provided. This attachment reference surface 15A is a surface substantially perpendicular to the optical axis of the second optical path. Further, the mount 15 has an opening 15B for passing the light L ₂ from the beam splitter 13 is provided. The light that has passed through the opening 15B is guided to the light receiving surface 22A of the image sensor 22 accommodated in the camera body 20 or the surface 32A of the reference substrate 32 of the calibration member 30, and is reflected there (light L _4). ).

The reflected light L ₃ from the surface of the reference substrate 14 and the reflected light L ₄ from the light receiving surface 22A of the image sensor 22 or the surface 32A of the reference substrate 32 are incident on the beam splitter 13 again and synthesized there. Is done. The combined light L ₅ passes through the imaging lens 16 and the diaphragm 17 and reaches the photodetector 18 (light L ₆ ). The imaging lens 16 is for maintaining a conjugate relationship between the reference substrate 14 or the standard substrate 32 and the photodetector 18. The diaphragm 17 is for removing noise light (for example, unnecessary light caused by reflection on the back surface of the reference substrate 14).

As shown in FIG. 3, the photodetector 18 includes photomultiplier tubes 41 to 45 arranged at a total of five locations including the center and four corners of a predetermined visual field region. The visual field region is a region corresponding to the light receiving surface 22A of the image sensor 22 in the camera body 20 (FIG. 1). Each of the photomultiplier tubes 41 to 45 detects the light amount of the light L ₆ that has reached through the diaphragm 17 and outputs a light amount signal to a control unit (not shown).
In the photomultiplier tube 41 arranged at the center of the visual field region, as shown in FIG. 4, the reflected light L _3C from the central portion 4C of the surface 14A of the reference substrate 14 and the light receiving surface 22A of the image sensor 22 or The amount of light L _6C is detected by combining with the reflected light L _4C from the central portion 2C of the surface 32A of the reference substrate 32. The light receiving portion of the photomultiplier tube 41, the central portion 4C of the surface 14A, and the central portion 2C of the light receiving surface 22A or the surface 32A are conjugate.

In addition, in a photomultiplier tube (for example, 42) arranged at the corner of the viewing area, the reflected light L _3S from the peripheral portion 4S of the surface 14A and the reflected light L _4S from the peripheral portion 2S of the light receiving surface 22A or the surface 32A. the amount of light L _6S is detected by synthesis and. The light receiving portion of the photomultiplier tube (for example, 42), the peripheral portion 4S of the surface 14A, and the peripheral portion 2S of the light receiving surface 22A or the surface 32A are conjugate.
The control unit (not shown) takes in the light quantity signals output from each of the photomultiplier tubes 41 to 45 of the photodetector 18 and determines whether or not white interference fringes have appeared. For this reason, the control unit captures the light amount signal from the photodetector 18 while translating the reference substrate 14 along the optical axis of the first optical path. The intensity of the light amount signal from the photodetector 18 changes greatly with the movement of the reference substrate 14 when white interference fringes appear.

And a control part judges whether white interference fringe appeared in said light _L6C based on the light quantity signal from photomultiplier tube 41 of the visual field center, and a reference board when the maximum light quantity signal appeared The position of the central portion 4C of the 14 surfaces 14A is detected. Further, for example, based on a light amount signal from the photomultiplier tube 42, it is determined whether or not white interference fringes appear in the light L _6S, and the periphery of the surface 14A of the reference substrate 14 when the maximum light amount signal appears. The position of the unit 4S is detected. That is, the control unit detects the position of the surface 14A when the maximum light amount signal of the white interference fringe appears at each of the five locations in the visual field region (detection means).

  Next, the measurement operation by the flange back measuring apparatus 10 of this embodiment will be described. Here, first, with the calibration member 30 attached to the mount 15 of the flange back measuring device 10 (FIG. 2), the reference point of the first optical path (that is, the origin of the surface 14A of the reference substrate 14) is determined, Further, the inclination state of the surface 14A of the reference substrate 14 is finely adjusted. Then, with the camera body 20 attached to the mount 15 (FIG. 1), the flange back of the body is measured.

  When the calibration member 30 is attached to the mount 15 of the flange back measuring apparatus 10 (FIG. 2), the flange 31A of the calibration member 30 is brought into contact with the mounting reference surface 15A of the mount 15 so as to be pressed. For this reason, the attachment reference surface 15A and the flange 31A coincide, and the distance D from the flange 31A to the surface 32A of the reference substrate 32 coincides with the distance from the attachment reference surface 15A to the surface 32A. Further, the surface 32A of the reference substrate 32 is substantially parallel to the attachment reference surface 15A and is substantially perpendicular to the optical axis of the second optical path. As described above, in the calibration member 30 used here, the distance D from the flange 31A to the surface 32A of the reference substrate 32 corresponds to the flange back design value (distance C) in the camera body 20, and is already known. is there.

  In this state, the reference point of the second optical path is defined in advance by the surface 32A of the reference substrate 32 of the calibration member 30. Therefore, the control unit determines that the reference point of the first optical path corresponding to the reference point of the second optical path (that is, the origin of the surface 14A of the reference substrate 14) is parallel to the reference substrate 14 along the optical axis of the first optical path. While moving, the light amount signal output from the photomultiplier tube 41 at the center of the visual field of the photodetector 18 is captured.

  Then, the position of the central portion 4C of the surface 14A of the reference substrate 14 when the maximum light quantity signal of the white interference fringe appears is detected as the reference point of the first optical path (the origin of the surface 14A of the reference substrate 14). At this time, the position of the central portion 4C is such that the distance from the beam splitter 13 to the central portion 4C coincides with the distance from the beam splitter 13 to the central portion 2C of the surface 32A of the reference substrate 32 (that is, the reference point of the second optical path). It is near.

  In addition, the control unit finely adjusts the tilt state of the surface 14A of the reference substrate 14, so that the other photomultiplier tubes 42˜ are simultaneously or at the same time as the capture of the light amount signal from the photomultiplier tube 41. The light quantity signal output from each of 45 is captured, and the positions of the surface 14A of the reference substrate 14 when white interference fringes appear are detected at four locations. The four places include the peripheral portion 4S illustrated in FIG.

  For example, the position of the peripheral portion 4S when white interference fringes appear is such that the distance from the beam splitter 13 to the peripheral portion 4S of the surface 14A is the distance from the beam splitter 13 to the peripheral portion 2S of the surface 32A of the reference substrate 32. It is a matching neighborhood. When the inclined state of the surface 14A (angle with respect to the optical axis of the first optical path) is different from the inclined state of the surface 32A (angle with respect to the optical axis of the second optical path), the detection position at the peripheral portion 4S is the center portion 4C described above. This is different from the detection position at.

  Therefore, the inclination state of the surface 14A can be finely adjusted so that the detection position at the peripheral portion 4S matches the detection position at the central portion 4C. As a result, the inclination state of the surface 14A can be matched with the inclination state of the surface 32A. In the present embodiment, as described above, since the surface 32A is substantially perpendicular to the optical axis of the second optical path, the surface 14A after fine adjustment is substantially perpendicular to the optical axis of the first optical path.

When the fine adjustment is completed, the light amount signals output from the photomultiplier tubes 41 to 45 of the photodetector 18 change in the same manner as the reference substrate 14 moves. At the same time, the contrast increases and at the same time white interference fringes appear.
When the determination of the reference point of the first optical path and the adjustment of the inclination of the surface 14A of the reference substrate 14 are thus completed, the calibration member 30 is removed from the mount 15, and the camera body 20 is attached in place of the calibration member 30 ( In addition to FIG. 1, a reference optical component 19 </ b> S is attached between the beam splitter 13 and the reference substrate 14 so as to be substantially parallel to the reference substrate 14. When the camera body 20 is attached to the mount 15, the flange 21 </ b> A of the camera body 20 is brought into contact with the reference mounting surface 15 </ b> A of the mount 15. For this reason, the attachment reference plane 15A and the flange 21A coincide.

As described above, in the determination step of the reference point of the first optical path, the distance D from the flange 31A of the support member 31 to the surface 32A of the reference substrate 32 is the light receiving surface of the imaging element 22 from the flange 21A of the camera body 20. The design value of the distance C up to 22A is set.
The reference optical component 19S disposed in the first optical path has the same configuration as various optical components 19 (here, an infrared cut filter and a low-pass filter) disposed on the lens side of the image sensor 22, A material having a very small thickness error relative to the design value (or a material in which the refractive index and the thickness error are accurately measured) may be selected. Therefore, the distance C from the attachment reference surface 15A to the light receiving surface 22A is substantially the same as the distance D from the attachment reference surface 15A to the surface 32A of the reference substrate 32 when the calibration member 30 is attached.

  However, when the image pickup device 22 is adjusted with an error in the design value or due to a manufacturing error with respect to the optical component 19S on which various values (filter thickness, parallelism, etc.) of the optical component 19 of the camera body 20 are a reference. When there is a difference, the distance C from the attachment reference surface 15A to the light receiving surface 22A and the distance D from the attachment reference surface 15A to the surface 32A of the reference substrate 32 when the calibration member 30 is attached are different values. . FIG. 5 clearly shows the difference between the distance C and the distance D, but the actual difference is very small.

  In this state, in order to measure the flange back of the body, the control unit moves the reference substrate 14 from the photomultiplier tube 41 at the center of the visual field of the photodetector 18 while translating the reference substrate 14 along the optical axis of the first optical path. Captures the output light quantity signal. The light quantity signal is as shown in FIG. 6, for example. 6 represents the position of the surface 14A of the reference substrate 14 (corresponding to the position of the stage). The vertical axis represents the voltage value of the light amount signal. The position where the maximum light amount signal of the white interference fringe is obtained coincides with the position D in FIG. 2 if there is no manufacturing error. If they do not match, the optical path difference based on the adjustment error of the image sensor 22 and the variation in the thickness of the optical component is measured (FIG. 5).

In the case of FIG. 6, two white interference fringes (F part and G part) appear in the light quantity signal. One of the two white interference fringes is reflected light L _3C from the central portion 4C (see FIG. 4) of the surface 14A of the reference substrate 14 and reflected light L _4C from the central portion 2C of the light receiving surface 22A of the image sensor 22. This is a white interference fringe that is combined with, and is the part that you want to use to measure the flange back of the body. The other is white interference fringes by combining the reflected light L _3C and the reflected light from the optical component disposed in front of the image sensor 22.

  In general, the reflectance at the light receiving surface 22A of the image sensor 22 and the optical component is known, and the contrast of the white interference fringes can be predicted based on each reflectance. Therefore, the control unit can definitely select the one to be used for measuring the flange back of the body based on the contrast of each white interference fringe appearing in the light amount signal (FIG. 6). In the example of FIG. 6, white interference fringes in the F part are selected.

  Then, the control unit detects the position H (FIG. 6) of the center part 4C of the surface 14A of the reference substrate 14 when the white interference fringes of the F part appear (for example, when the contrast is maximized). A distance δ from the reference point of one optical path (the origin of the surface 14A of the reference substrate 14) to the detection position H is calculated. The detection position H is a vicinity where the distance from the beam splitter 13 to the central portion 4C coincides with the optical distance from the beam splitter 13 to the central portion 2C of the light receiving surface 22A of the image sensor 22.

When the calculation of the distance δ from the reference point of the first optical path to the detection position H is completed in this way, the control unit follows the following equation (1) and the distance δ of the calculated value and the known (design value) distance: Based on D, the flange back of the body (that is, the optical distance C) is calculated.
C = D−δ (1)
In the flange back measuring apparatus 10 of the present embodiment, the light receiving surface 22A of the image sensor 22 can be captured with high accuracy by utilizing the principle of white interference, and the flange back (that is, optical distance) of the body of the digital camera. C) can be measured with high accuracy. The measurement reproducibility is about 5 μm. Therefore, the light receiving surface 22A of the image sensor 22 can be positioned with high accuracy with respect to the flange 21A of the camera body 20.

  Moreover, in the flange back measuring apparatus 10 of this embodiment, the angle (tilt state) of the light receiving surface 22A of the image sensor 22 with respect to the flange 21A can be measured as follows. For the inclination measurement, the control unit captures the light amount signal output from each of the other photomultiplier tubes 42 to 45 at the same time as the capturing of the light amount signal (FIG. 6) or at a different timing, and white interference fringes. Is detected at four locations (including the peripheral portion 4S in FIG. 4).

Then, the inclination angle of the light receiving surface 22A of the imaging element 22 is calculated based on the detection positions of the surface 14A at the four locations and the intervals between the photomultiplier tubes 42 to 45 in the light detection unit 18. Also in this case, since the principle of white interference is used, the tilt angle can be measured with high accuracy. Based on this measurement value, the parallelism of the light receiving surface 22A of the image sensor 22 with respect to the flange 21A of the camera body 20 can be adjusted with high accuracy.
(Modification)
In the above-described embodiment, the optical component arranged on the lens side with respect to the image pickup element 22 is an infrared cut filter and a low-pass filter. However, other components may be arranged, and other combinations or single components are also possible. It may be a part. Here, when a microlens is disposed as an optical component, when the optical component 19S serving as a reference is disposed, the distance between the microlens and the reference substrate 14 is set to the distance between the microlens of the optical component 19 and the light receiving surface 22A. Must be the same as the distance.

  In the above embodiment, the distance D of the calibration member 30 is described as corresponding to the optical distance design value corresponding to the distance C of the camera body 20, but the present invention is not limited to this. Instead of the calibration member 30, a camera having a known reference between the flange 21 </ b> A and the light receiving surface 22 </ b> A of the image sensor 22 is attached to the mount 15 to determine the reference point of the first optical path and adjust the inclination of the reference substrate 14. You can go. Moreover, although the known value was used as the distance D of the calibration member 30 and the flange back of the body was calculated, the present invention is not limited to this. The distance D may be measured by another device, and the flange back may be calculated using the measured value. As another apparatus, for example, a Michelson interferometer similar to the flange back measuring apparatus 10 of the present embodiment, a micro gauge, or the like can be used.

Further, in the above-described embodiment, the example in which the photodetector 18 includes the five photomultiplier tubes 41 to 45 has been described, but the present invention is not limited to this. The number of photomultiplier tubes may be three, four, six or more. Instead of the photomultiplier tube, another detector or an area sensor may be used.
In the above-described embodiment, the digital still camera has been described as an example. However, the present invention can also be applied to a digital video camera capable of shooting a moving image. In this specification, the generic name of a digital still camera and a digital video camera corresponds to “digital camera”.

  Furthermore, in the above-described embodiment, an example in which the reference substrate 14 has a wedge shape has been described, but a parallel planar shape may be used. In this case, it is preferable that an antireflection film is provided on the back surface, a roughening process is performed, or a black matting process is performed.

It is a figure which shows the state which mounted | wore the flange back measuring apparatus 10 with the camera body 20 of a measuring object. It is a figure which shows the state which mounted | wore the flange back measuring apparatus 10 with the calibration member 30. FIG. FIG. 3 is a diagram illustrating a configuration of a photodetector 18. It is a figure explaining the light which injects into the photomultiplier tubes 41 and 42 of a visual field center and a periphery. It is a figure explaining measurement operation by flange back measuring device. It is a figure which shows an example of the light quantity signal output from the photodetector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Flange back measuring apparatus 11 White light source 12 Collimator 13 Beam splitter 14 Reference board | substrates 15 and 21 Mount 16 Imaging lens 17 Aperture 18 Optical detector 19 Optical component 19S (such as a filter) Optical component 20 serving as a reference (such as a filter) Camera body 22 Image sensor 30 Calibration member 31 Support member 32 Reference substrates 41 to 45 Photomultiplier tube

Claims (3)

A white light source,
A split member that divides light from the white light source into two, guides one light to the first optical path, and guides the other light to the second optical path;
A movable member arranged to be movable along the first optical path and reflecting the one light from the split member;
The camera body that is fixedly disposed in the second optical path, holds a camera body to be measured, and has a mounting reference surface that can come into contact with a flange of the camera body, and transmits the other light from the split member to the camera body A fixing member that leads to an image sensor housed in
Detecting means for detecting a position of the movable member when a maximum light quantity signal of a white interference fringe appears by combining the reflected light from the movable member and the reflected light from the imaging element of the camera body;
Based on a distance from the mounting reference plane of the fixing member to a predetermined reference point of the second optical path, and a distance from a reference point of the first optical path corresponding to the reference point to a detection position by the detection means. And a calculating means for calculating a distance from the flange of the camera body to the imaging device. In the flange back measuring device according to claim 1,
The detecting means detects the position of the movable member when the maximum light quantity signal of the white interference fringes appears in at least three places in a predetermined visual field area;
The said calculation means calculates the inclination of the said image sensor with respect to the said flange in addition to calculation of the distance from the said flange to the said image sensor. The flange back measuring apparatus characterized by the above-mentioned. In the flange back measuring device according to claim 1 or 2,
The fixing member has a flange that can come into contact with the mounting reference plane instead of the camera body, and a plane that defines the reference point of the second optical path is disposed at a predetermined distance from the flange. Calibration members can be held,
The detection means has a maximum light amount signal of white interference fringes by combining the reflected light from the movable member and the reflected light from the specified surface of the calibration member in a state where the calibration member is held by the fixed member. A flange back measuring device, wherein the position of the movable member at the time when appears is detected as a reference point of the first optical path.

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