JP2009287979A - Optical measuring apparatus and focus adjustment method for optical measuring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical measuring apparatus which can reduce shading caused by the configuration of a detector. <P>SOLUTION: The optical measuring apparatus 1 includes: a collecting lens 21 for projecting light from a planar light source 101 as an object under measurement; a visual field stop member 23, arranged at the conjugate point with respect to the planar light source 101 via the collecting lens 21; a relay lens 25 for projecting the light from the planar light source 101, passed through the visual field stop member 23; and a detector 7 which has an incidence section 27 in which a plurality of incident faces 31a, which the light projected by the relay lens 25 enters, are arranged so that they have gaps between the incident faces 31a and outputs a signal responsive to the light which enters the plurality of incidence faces 31a. The plurality of incidence faces 31a are arranged, at displaced positions from the conjugate point with respect to the visual field stop member 23 via the relay lens 25 in the optical axis direction of the relay lens 25. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical measurement device that measures an amount of light such as luminance and chromaticity in a light source, and a focus adjustment method for the optical measurement device.

A technique for measuring a physical quantity or a psychophysical quantity such as luminance and chromaticity of a light source is known. In Patent Document 1, as a collecting device that collects optical information of a web such as paper, a galvano mirror that scans the web by sequentially deflecting light from each part of the web, and light that is deflected by the galvano mirror 2 is transmitted. An apparatus having two slits and a spectroscope that separates light transmitted through the two slits is disclosed. Further, a spectroscope that has an incident portion constituted by a plurality of optical fibers (multi-core fibers) and separates light incident on the multi-core fibers is known (for example, Patent Document 2).
JP 2004-93326 A JP 2006-162509 A

  When the light from the light source is incident on the multi-core fiber, an optical system may be disposed between the light source and the multi-core fiber so that an image of the light source is formed on the incident surface of the multi-core fiber. However, since the incident surface of the multicore fiber is a set of incident surfaces of a plurality of optical fibers, light is not taken in the gaps between the plurality of optical fibers. That is, local light in the measurement region is taken into the detector and vignetting occurs. In this case, it cannot be said that the light in the entire measurement region is accurately measured.

  An object of the present invention is to provide an optical measurement device and a focus adjustment method for the optical measurement device that can suppress vignetting caused by the configuration of the detector.

  An optical measurement device of the present invention includes a first optical system that projects light from a light source to be measured as a measurement target, and a field stop member that is disposed at a conjugate point of the light source to be measured via the first optical system. A second optical system that projects light from the light source to be measured that has passed through the field stop member, and a plurality of incident surfaces on which the light projected by the second optical system is incident are gaps between the plurality of incident surfaces And a detector that outputs a signal corresponding to light incident on the plurality of incident surfaces, and the plurality of incident surfaces include the second optical system. And disposed at a position shifted from the conjugate point of the field stop member via the optical axis direction of the second optical system.

  The focus adjustment method of the optical measurement device of the present invention includes a first optical system that projects light from a light source to be measured as a measurement target, and a field of view that is disposed at a conjugate point of the light source to be measured via the first optical system. A diaphragm member, a second optical system that projects light from the light source to be measured that has passed through the field diaphragm member, and a plurality of incident surfaces on which light projected by the second optical system is incident are between the plurality of incident surfaces The incident part of a detector having an incident part arranged so as to generate a gap, and a main body part that receives light guided by the incident part and outputs a signal according to the received light, and A replacement backprojection light source connected to the incident portion instead of the main body portion and capable of emitting light from the plurality of incident surfaces, and the first optical system and the field stop disposed therewith At least the member, the second optical system, and the incident portion One is moved, the image of the field stop member and the plurality of incident surfaces are focused on the arrangement position of the light source to be measured, and after the focus, the incident portion is moved, and the arrangement of the light source to be measured The images of the plurality of incident surfaces at the positions are defocused, and after the defocusing, the main body portion is connected to the incident portion instead of the replacement type back projection light source.

  According to the present invention, vignetting caused by the configuration of the detector can be suppressed.

(First embodiment)
(Schematic configuration of the optical measurement device)
FIG. 1 is a simplified diagram illustrating a schematic configuration of an optical measurement device 1 according to an embodiment of the present invention, in which FIG. 1 (a) is a plan view and FIG. 1 (b) is a side view.

  The optical measurement device 1 is configured as a device that measures the distribution of light-related quantities such as the luminance distribution and chromaticity distribution of the surface light source 101 that is the measurement target. The surface light source 101 is a display device that performs display by adjusting the brightness for each of a plurality of pixels, such as a liquid crystal display or an organic EL display. The planar shape of the surface light source 101 (the shape viewed from the right side in FIG. 1) may be set as appropriate. For example, a predetermined direction (horizontal direction in the example of this embodiment, vertical direction in FIG. 1A). FIG. 1B is a rectangle whose longitudinal direction is the paper surface penetration direction. In a general display device, the aspect ratio (length in the longitudinal direction: length in the short direction) = 16: 9.

  The optical measuring device 1 includes a space dividing device 3 that performs an operation of sequentially taking in light of each part (measurement region A) of the surface light source 101, an optical condensing device 5 that collects light taken in by the space dividing device 3, and A detector 7 that receives light collected by the optical condensing device 5 and outputs a signal corresponding to the received light, and an arithmetic device that performs processing based on the control of the space dividing device 3 and the detection result of the detector 7 9 (FIG. 1A) and a back projection device 11 (FIG. 1B) for adjusting the focus of the optical condensing device 5.

(Arrangement of space dividing device and other devices)
The space dividing device 3 includes, for example, one galvanometer mirror 13 and a first motor 15 and a second motor 17 that drive the galvanometer mirror 13.

  The galvanometer mirror 13 is for sequentially deflecting the light from each part of the surface light source 101 in a certain direction (direction of the optical condensing device 5, indicated by an arrow aw1). The galvanometer mirror 13 is subjected to surface treatment such as metal coating and multilayer coating. The galvanometer mirror 13 is rotatably supported around the first axis AX1 and the second axis AX2 (about two axes). The first axis AX1 is, for example, an axis extending in the short direction of the surface light source 101 (the paper surface penetration direction in FIG. 1A and the vertical direction in FIG. 1B), and the second axis AX2 is, for example, This is an axis extending in the longitudinal direction of the surface light source 101 (the vertical direction of the paper surface in FIG. 1A, the through direction of the paper surface in FIG. 1B).

  By rotating the galvanometer mirror 13 about the first axis AX1, a portion (measurement region A) of the surface light source 101 where light is taken into the optical condensing device 5 and the detector 7 is in the longitudinal direction of the surface light source 101. Moving. That is, the surface light source 101 is scanned in the longitudinal direction. Similarly, when the galvanometer mirror 13 rotates about the second axis AX2, the measurement region A moves in the short direction of the surface light source 101, and the surface light source 101 is scanned in the short direction.

  The first motor 15 drives the galvanometer mirror 13 around the first axis AX1. The second motor 17 drives the galvanometer mirror 13 around the second axis AX2. The operations of the first motor 15 and the second motor 17 are controlled by the arithmetic unit 9, for example. The space dividing device 3 includes a support mechanism for the galvanometer mirror 13 and a transmission mechanism for transmitting the rotations of the first motor 15 and the second motor 17 to the galvanometer mirror 13, but illustration thereof is omitted.

  An optical system on which light deflected by the galvanometer mirror 13 is incident (for example, the optical condensing device 5. However, a part of the optical concentrating device 5 on the galvano mirror 13 side may be used. The diaphragm member 19 and the condenser lens 21 may be disposed on the surface light source 101 side with respect to the galvanometer mirror 13, for example.

  However, the optical condensing device 5 is disposed outside the optical path from the surface light source 101 to the galvanometer mirror 13 so as not to block light traveling from the surface light source 101 to the galvanometer mirror 13. Specifically, as shown in FIG. 1B, the optical condensing device 5 has a shorter light path direction than the light path from the end of the surface light source 101 in the short direction to the galvanometer mirror 13. Are disposed outside the surface light source 101. However, in the longitudinal direction of the surface light source 101, the optical condensing device 5 is located on the center side of the surface light source from the end of the surface light source 101 in the longitudinal direction to the galvanometer mirror 13, as shown in FIG. Is arranged. Preferably, the optical condensing device 5 is disposed at the center of the surface light source 101 in the longitudinal direction of the surface light source 101.

  FIG. 2 is a diagram for explaining the operation of the configuration of the space dividing device of this embodiment and the arrangement of other devices. FIG. 2A is a cross-sectional view showing the definition of the incident angle, and FIG. ) Is a diagram showing the influence of the incident angle on the reflectance for each wavelength of light.

  As shown in FIG. 2A, the incident angle is defined by the angle of light with respect to a line (normal line) orthogonal to the reflecting surface (galvano mirror 13). As shown in FIG. 2B, the reflectance decreases as the incident angle increases. That is, the reflectance has an angle dependency. Further, the reflectance and the angle dependency thereof are different for each wavelength. Such angle dependency and wavelength dependency are caused by, for example, metal coating, multilayer coating, or the like.

  In general, in an optical measurement device, the incident angle of light from a surface light source on a galvanometer mirror increases as the light on the outer peripheral side of the surface light source is captured. Accordingly, the reflectance of the galvanometer mirror changes between when measuring the center side of the surface light source and when measuring the outside of the surface light source, which results in a measurement error. The correction of the error caused by the change in reflectance due to the incident angle must consider not only the change in incident angle but also the wavelength dependence of the reflectance. Further, if the change is made using a plurality of galvanometer mirrors, the correction becomes more complicated.

  Here, the change in reflectivity according to the incident angle increases as the incident angle increases. For example, when the measured value of the luminance of the xenon lamp is compared between the incident angle of 23 degrees and 45 degrees, the error is about 0.2%, and the incident angle is 45 degrees and 68 degrees. In comparison, the error is about 2.0%.

  In this embodiment, the optical condensing device 5 is disposed on the surface light source 101 side with respect to the galvanometer mirror 13. Therefore, for example, the incident angle to the galvanometer mirror 13 can be reduced as compared with the case where the optical condensing device 5 is arranged immediately below the galvanometer mirror 13 in FIG. Furthermore, the optical condensing device 5 has a surface in the shorter direction of the surface light source 101 than the light path from the end in the shorter direction of the surface light source 101 to the galvanometer mirror 13 so as not to block the light from the surface light source 101. It is arranged outside the light source 101. Therefore, on the contrary, the incident angle to the galvanometer mirror 13 can be further reduced as compared with the case where the optical condensing device 5 is disposed outside the surface light source 101 in the longitudinal direction of the surface light source 101. it can. As a result, a change in reflectance due to the incident angle can be suppressed, and the measurement error can be reduced.

  In addition, the maximum value of the incident angle to the galvanometer mirror 13 is the angle β shown in FIG. 1A or the angle γ shown in FIG. The angle β is an angle formed by the optical path from the longitudinal end of the surface light source 101 to the galvanometer mirror 13 and the optical path from the galvanometer mirror 13 to the optical condenser 5. The angle γ is the angle formed by the optical path from the edge of the surface light source 101 on the side opposite to the optical condensing device 5 to the galvano mirror 13 and the optical path from the galvano mirror 13 to the optical condensing device 5. It is. The optical condensing device 5 is preferably arranged such that the angles β and γ are 45 degrees or less.

  In the present embodiment, the space dividing device 3 that two-dimensionally scans the surface light source 101 includes one galvanometer mirror 13 that can rotate about two axes. Therefore, since the number of reflections is reduced as compared with a case where a spatial division device capable of two-dimensional scanning is configured by combining two galvanometer mirrors that can rotate around one axis, a change in reflectance is suppressed. In addition, correction of the measurement result in consideration of the reflectance is facilitated.

(Optical condensing device and detector)
FIG. 3 is a perspective view showing the main parts of the optical condensing device 5 and the detector 7. FIG. 4 is an optical path diagram in the optical condensing device 5 and the detector 7. In FIG. 4, for easy understanding, the space dividing device 3 is omitted, and the optical condensing device 5 and the detector 7 are illustrated in front of the surface light source 101.

  The optical condensing device 5 includes an aperture stop member 19 to which the light deflected by the space dividing device 3 is incident, a condensing lens 21 to which light transmitted through the aperture stop member 19 is incident, and light transmitted through the condensing lens 21. Has a field stop member 23 and a relay lens 25 to which light transmitted through the field stop member 23 enters.

  In addition, the detector 7 includes an incident portion 27 on which light transmitted through the relay lens 25 is incident, and a main body portion 29 that receives light guided by the incident portion 27 and outputs a signal corresponding to the received light. Have.

  The aperture stop member 19 is disposed, for example, at the front focal point of the condenser lens 21. The aperture stop member 19 is formed with an aperture stop 19a that transmits the light from the space dividing device 3 while defining its diameter (cross section). The aperture stop member 19 may have a fixed or variable diameter of the aperture stop 19a.

  The condenser lens 21 forms an image of light from the surface light source 101 by condensing the light transmitted through the aperture stop 19a. The condensing lens 21 may be constituted by a single lens or a lens group. The diameter of the condensing lens 21 is set to a size that allows all light from the aperture stop 19a to enter.

  The field stop member 23 is disposed, for example, on the image plane of the condenser lens 21. The field stop member 23 is formed with a field stop 23a that transmits the light collected by the condenser lens 21 while defining the diameter (cross section) thereof. The field stop 23a is, for example, an opening of 0.3 to 3 mm. The shape of the field stop 23a may be an appropriate shape, but is, for example, a circle or a rectangle. The field stop member 23 may have a fixed or variable diameter of the field stop 23a.

  The relay lens 25 is a lens that transfers an image formed by the condenser lens 21. As described above, since the field stop member 23 is disposed on the image plane of the condenser lens 21, the relay lens 25 transfers an image whose diameter is defined by the field stop member 23. The relay lens 25 may be appropriately configured, and may be disposed at an appropriate position according to the configuration of the relay lens 25. For example, the relay lens 25 is composed of an afocal optical system, and forms an image of an object at a magnification determined by the ratio of the front focal length f2 and the rear focal length f3 (FIG. 4). Further, in this case, for example, the relay lens 25 is arranged so that the front focal point is positioned on the field stop member 23 and forms an image of the surface light source 101 defined by the field stop member 23 on the rear focal point.

  The incident portion 27 of the detector 7 is configured to have, for example, a bundle of a plurality of optical fibers 31 (see FIG. 7A). The incident surface 27 a of the incident portion 27 is configured by a plurality of incident surfaces 31 a (see FIG. 7A) configured by the end surface of the optical fiber 31. The incident surface 27a is disposed near the conjugate point P1 (FIG. 4) of the field stop member 23 via the relay lens 25 and at a position shifted from the conjugate point P1 in the optical axis direction of the relay lens 25. In other words, the incident surface 27a is disposed in the vicinity of the conjugate point P1 (FIG. 4) of the surface light source 101 via the optical condensing device 5 and at a position shifted from the conjugate point P1 in the optical axis direction of the optical condensing device 5. ing. The incident surface 27a may be shifted to either the relay lens 25 side or the opposite side with respect to the conjugate point P1.

  The main body 29 of the detector 7 is constituted by a spectroscope, for example. Note that the entire detector 7 may be regarded as a spectroscope. The main body 29 receives the light guided by the optical fiber 31, divides the received light to obtain the spectrum of the light, and obtains the spectrum data or the brightness and chromaticity calculated from the spectrum. And output as an electrical signal. The detector 7 receives, for example, a so-called narrow-spectrum spectroscope such as a monochromator and light split by the narrow-spectrum spectroscope, and outputs an electric signal corresponding to the amount of the received light, although not particularly illustrated. And a photoelectric converter such as a CCD.

  As shown in FIG. 3, the optical measurement device 1 includes a first holding unit 33 that holds the aperture stop member 19 and the condenser lens 21, and a first holding unit 33 that holds the field stop member 23, the relay lens 25, and the incident unit 27. 2 and a base 37 that holds the first holding part 33 and the second holding part 35 so as to be relatively movable in the optical axis direction of the condenser lens 21 (left and right direction in FIG. 3). Therefore, the optical measurement device 1 can position (focus) the field stop member 23 on the image plane of the condenser lens 21 by the relative movement of the first holding unit 33 and the second holding unit 35.

  The material, shape, and movement mechanism of the first holding unit 33, the second holding unit 35, and the base 37 may be selected as appropriate. The relative movement of the first holding unit 33 and the second holding unit 35 may be realized by moving either the first holding unit 33 or the second holding unit 35, or by moving both of them. Moreover, it may be driven by human power or may be driven by a driving device such as a motor. The positions of the optical members held by the first holding unit 33 and the optical members held by the second holding unit 35 may be adjustable. The main body 29 of the detector 7 may or may not be held by the second holding unit 35.

  Prior to the description of the operation of the optical condensing device 5, the measurement distance, the measurement area, the measurement angle, the solid angle, and the amount of captured light will be described.

  The measurement distance (see L in FIG. 5B) is the distance between the surface light source 101 and the optical condensing device 5. In addition, although the position used as the reference | standard of measurement distance in the optical condensing apparatus 5 may be selected suitably, it is an arrangement position of the condensing lens 21, for example.

  The measurement area (see Sm in FIG. 5B) is the area on the surface light source 101, and is the area of the measurement region A (see FIG. 1) to be measured at each scanning time point. That is, the area of the light source of the light output from the optical condensing device 5 to the detector 7 at a temporary point.

  The measurement angle (see 2α in FIG. 5B) is an angle at which the measurement region A is viewed from the optical condensing device 5. That is, the measurement angle indicates the size of the measurement region A as an angle with respect to the optical axis of the optical condensing device 5. The measurement area is a function of the measurement angle and the measurement distance.

  The solid angle (unit: steradian) is generally defined by S / r2. r is the radius of the sphere, and S is the area of a predetermined portion of the surface of the sphere. In the present embodiment, the solid angle is defined in a cone formed by light rays emitted from each point on the surface light source 101. Since the solid angle correlates with the apex angle ω in FIG. 5B, the apex angle ω may be considered as a solid angle.

  The amount of captured light is the amount of light per unit time that is emitted from the measurement region A, captured by the optical condensing device 5, and output to the detector 7.

  The operation of the optical condensing device 5 will be described.

  Since the aperture stop member 19 is disposed on the front side of the condenser lens 21, the diameter of the light incident on the condenser lens 21 can be defined. That is, the aperture stop member 19 can define the solid angle of light taken into the optical condensing device 5 by the aperture stop 19a. When the aperture stop member 19 has a variable size of the aperture stop 19a, the solid angle can be adjusted by adjusting the size of the aperture stop 19a.

  The condenser lens 21 connects the images of the surface light source 101, and the field stop member 23 is disposed on the image plane of the condenser lens 21. That is, the surface light source 101 and the field stop member 23 are conjugate. Therefore, the measurement area and the like can be defined by the area of the field stop 23a. When the field stop member 23 has a variable size of the field stop 23a, the measurement area and the like can be adjusted by adjusting the size of the field stop 23a.

  As described above, the condenser lens 21 is disposed so that the front focal point is located on the aperture stop member 19. As a result, there is an effect that the amount of captured light becomes constant regardless of the measurement distance. Specifically, it is as follows.

  FIG. 5A is a diagram illustrating the measurement angle 2α.

When the object height h (half the height of the measurement area A) and the image height h ′ (half the height of the field stop 23a) are always in an imaging relationship, the following equation holds.
h / h ′ = x / f
h / x = h ′ / f
Here, it can be seen that h / x is always constant because the focal length f and the radius h 'of the field stop 23a are unchanged.

On the other hand, if the measurement angle 2α is composed of triangles made of x and h,
2α = 2 tan ⁻¹ (h / x)
It becomes.

  As described above, the reference for the measurement angle 2α is the front focal point of the condenser lens 21. Even if the measurement distance L (x in FIG. 5A) changes, the measurement angle 2α does not change. In order to change the measurement angle 2α, the diameter (h ′) of the field stop 23a must be changed.

  FIG. 5B is a diagram for explaining an operation in which the amount of captured light becomes constant.

The measurement area Sm is determined by the measurement angle 2α and the measurement distance L. For example, if the shape of the field stop 23a, in other words, the shape of the measurement region A is circular, the radius is (L−f1) tan α, so Sm = π ((L−f1) tan α) ^2. It becomes.

When the energy of the point light source in the measurement area A is considered as P, the light flux density at the position of the entrance pupil (aperture stop 19a) is a value obtained by dividing the energy P by the surface area of a sphere having a radius L-f1. Therefore, P / (4π (L−f1) ² ).

At this time, the solid angle of capture is defined by the cone apex angle ω of the light beam captured by the entrance pupil as viewed from the light source. Assuming that the entrance pupil diameter is 2R, the amount of captured light limited by the solid angle among the light rays emitted from the point light source is obtained by multiplying the luminous flux density at the position of the entrance pupil by the area πR ^{2 of the} entrance pupil, and P · R ² / (4 (L−f1) ² ).

Since the amount of captured light is determined by the relationship of measurement area × “captured amount of light limited by solid angle among rays emitted from a point light source”, π ((L−f1) tanα) ² × P · R ² / (4 (L-f1) ² )
= (P · πR ² · tan α) / 4
Therefore, the captured light quantity as a measuring instrument is determined by the measurement angle α, the pupil diameter R, and the energy P of the light source. This means that the change amount of the measurement area due to the change of the measurement distance is offset by the change of the solid angle which also changes with the measurement distance.

  That is, in the optical condensing device 5, even if the measurement distance L is changed, the amount of light captured from a certain position of the surface light source 101 (for example, the center position of the surface light source 101) does not change. Further, as a result of such an action, the amount of captured light when the measurement region A is located at the center of the surface light source 101 and the amount of captured light when the measurement region A is located at the outer peripheral portion of the surface light source 101 are: Regardless of the measurement distance L, a constant relationship (a constant ratio) is maintained. As a result, for example, it is possible to measure the absolute value of the luminance. In addition, when performing shading correction or the like, there is no need to perform different processing depending on the measurement distance.

  When the measurement distance L changes, the position of the image plane of the condenser lens 21 changes. However, since the optical measuring device 5 can move the second holding unit 35 in the optical axis direction with respect to the first holding unit 33, the aperture stop member 19 is positioned at the front focal point of the condenser lens 21. Adjustment (focus adjustment, focusing) can be performed so that the field stop member 23 is positioned on the image plane of the condenser lens 21.

  In the optical condensing device 5, by changing the diameter of the aperture stop, the solid angle can be changed to adjust the amount of captured light. The adjustment does not need to be performed in consideration of the difference in the light attenuation rate for each wavelength unlike the adjustment of the amount of captured light by the ND filter. That is, since the ND filter has a different attenuation rate for each wavelength, when the amount of captured light is adjusted using the ND filter, the detection value needs to be corrected in order to reduce the measurement error. In form, it is not necessary.

  The aperture stop member may be composed of a plurality of aperture blades and change the diameter of the aperture stop by relative movement of the plurality of aperture blades, like a shutter of an imaging apparatus. Further, for example, the aperture stop member is rotatably supported, and a plurality of stops are formed along the circumferential direction. By changing the stop inserted into the optical path by the rotational movement, the aperture stop diameter is changed. It may be a turret that changes. The optical condensing device 5 may be detachable with a plurality of aperture stop members having different aperture stop diameters.

  The optical condensing device 5 keeps the measurement accuracy high while increasing the amount of captured light, as compared with the technique (two-iris method) that transmits light from the galvanometer mirror through the two slits disclosed in Patent Document 1 described above. be able to. That is, in the technique of Patent Document 1, the smaller the second slit is, the better the measurement accuracy is. However, if the second slit is too small, the amount of light is reduced, so the measurement accuracy and the amount of light are increased. It is difficult to achieve both. However, in this embodiment, it is not necessary to reduce the aperture stop 19a and the field stop 23a in order to increase the measurement accuracy. As a result, light can be taken in by the aperture stop 19a and the field stop 23a which are larger than the slit of Patent Document 1.

  The operation due to the fact that the incident surface 27a of the incident portion 27 of the detector 7 is displaced from the conjugate point P1 will be described. In order to facilitate understanding, the operation will be described with reference to an image projected onto the surface light source 101 by the optical condensing device 5 when light is emitted from the incident surface 27a.

  FIG. 6 is an optical path diagram of the optical measurement device 1 in a state where a substitution type back projection light source 39 is connected to the incident portion 27 instead of the main body portion 29 of the detector 7.

  The light generated by the replacement-type back projection light source 39 is emitted from the incident surface 27 a and projected onto the surface light source 101 through the optical condensing device 5. An appropriate screen may be arranged at the position of the surface light source 101 instead of the surface light source 101.

  FIG. 7A is a diagram illustrating the incident surface 27 a of the incident portion 27.

  The incident surface 27a has a plurality of incident surfaces 31a as described above. The plurality of incident surfaces 31a are arranged such that gaps are formed between the plurality of incident surfaces 31a because the cross section of the optical fiber 31 is circular. Therefore, assuming that the incident surface 27a is disposed at the conjugate point P1 (FIG. 4) of the surface light source 101, the surface light source 101 forms an image of the incident surface 27a shown in FIG. Become. That is, in the surface light source 101, a portion having a high luminance corresponding to each optical fiber 31 and a portion having a low luminance corresponding to a gap between the plurality of optical fibers 31 are generated.

  This is because when light from the surface light source 101 is incident on the incident surface 27 a and the light from the surface light source 101 is measured by the detector 7, the light in the measurement region A of the surface light source 101 is locally detected by the detector 7. This is equivalent to the occurrence of vignetting. In this case, it is difficult to say that the light in the entire measurement region A is detected with high accuracy.

  Thus, it is conceivable to capture a defocused image from the surface light source 101 on the incident surface 27a. This corresponds to the projection of the defocused image shown in FIG. 7C onto the surface light source 101 when the back projection shown in FIG. 6 is performed. In FIG. 7C, images of the plurality of optical fibers 31 are not formed, and light is uniformly projected onto the surface light source 101. Therefore, vignetting is suppressed when light from the surface light source 101 is incident on the incident surface 27a.

  However, as shown in FIG. 7 (c), the contour of the image is blurred. When the light from the surface light source 101 is detected by the detector 7, the measurement region A (measurement area Sm) is accurately determined. This is equivalent to undefined. Further, depending on the way of defocusing, the positional relationship in which the captured light amount is constant is not established, and the captured light amount is not constant. As described above, the error increases depending on the defocusing method. Also, the operator cannot determine how much defocusing is allowed.

  In the present embodiment, as described with reference to FIG. 4, defocusing is performed by shifting the incident surface 27a from the conjugate point P1. As a result, when back projection shown in FIG. 6 is performed, the contour shown in FIG. 7B is clear and an image with a blurred interior is connected to the surface light source 101. This is because when the light from the surface light source 101 is detected by the detector 7, the measurement area A is accurately determined, the positional relationship in which the amount of captured light is constant is maintained, and the light in the entire measurement area A is This is equivalent to capturing without vignetting.

  By shifting the incident surface 27a from the conjugate point P1, the image shown in FIG. 7B is obtained because the image of the incident surface 27a is blurred at the position of the field stop member 23 but at the position of the field stop member 23. This is because the image is focused on the surface light source 101.

  In the present embodiment, the field stop member 23, the relay lens 25, and the incident portion 27 are held by the second holding portion 35, and are condensed with respect to the first holding portion 33 (the condensing lens 21). Since the lens 21 is movable in the optical axis direction, the field stop member 23 is collected according to the change in the measurement distance L while keeping the deviation amount t (FIG. 4) of the incident surface 27a from the conjugate point P1 constant. It can be positioned on the image plane of the optical lens 21 (focus adjustment). As a result, the operator can maintain the defocus amount set by the manufacturer of the optical measuring device 1 or an appropriate defocus amount set in advance by the worker. That is, it is not necessary to determine the defocus amount according to the measurement distance L.

  In addition, about the deviation | shift amount t from the conjugate point P1 of the entrance plane 27a, you may set suitably according to various situations, such as the precision requested | required for a measurement, the measurement precision of the detector 7, and the measurement distance L.

  For example, the shift amount t is the amount of captured light compared to the case where the optical condensing device 5 is not provided (for example, the 2-iris method) due to the light collected from the surface light source 101 by the optical condensing device 5. It is set so that the increase effect is not lost. For example, the shift amount t is set smaller than the rear focal length f3 of the relay lens 25.

  In addition, for example, the shift amount t is the amount of the plurality of incident surfaces 31 a projected on the position of the surface light source 101 by an operator who visually recognizes the surface light source 101 from an appropriate position when the back projection shown in FIG. 6 is performed. It is set to be equal to or greater than the value when the image is recognized as blurred.

  More preferably, when the back projection shown in FIG. 6 is performed, the shift amount t is visually recognized by the operator who visually recognizes the surface light source 101 from an appropriate position (the image shown in FIG. 7B). Is set to a value equal to or higher than the value when brightness unevenness is not recognized in the interior of the image, and images of the plurality of incident surfaces 31a are not recognized.

  It should be noted that there are individual differences in the recognition of unevenness in luminance, and consequently the determination of whether or not it is blurred, and the determination of whether or not it is the image shown in FIG. 7B, and conditions such as spatial frequency Also affected. However, the determination can be made by experimenting with a plurality of subjects using the optical measurement device 1.

  Various evaluation methods that can contribute to such a determination have been proposed, and the determination may be made by appropriately using such an evaluation method.

  For example, in “Study on high-precision detection method for printed matter with slight shading” (Yamashita et al., Mitsubishi Heavy Industries Technical Report, Vol. 35, No. 3, pages 202-205), an evaluation for determining presence / absence of luminance unevenness based on captured images A method for calculating a value is disclosed. The evaluation value is calculated considering that human perception of shading differs for each spatial frequency. Specifically, it is as follows.

First, a visual target is imaged, and the captured image is two-dimensionally Fourier transformed to calculate a power spectrum for each spatial frequency (f). Next, the power spectrum is multiplied by a weighting factor H (f) set for each spatial frequency. The weighting coefficient is expressed by the following equation.
H (f) = 0.31 + 0.69fe− ^0.29f
The multiplication result is inverse Fourier transformed to obtain a transformed image. Then, the standard deviation of the converted image (standard deviation of the luminance level) is calculated as an evaluation value.

  In the above research results, the subject's perception of unevenness and the evaluation value are compared for 20 subjects. According to the comparison result, when the evaluation value is around 0.6, unevenness is perceived by some of the subjects, and when the evaluation value exceeds 0.8, unevenness is perceived by almost all of the subjects. The above research report concludes that it is possible to detect unevenness felt by a person by setting the threshold value to 0.6 and using the evaluation value.

  Therefore, according to the above research report, the back projection shown in FIG. 6 is performed, an image at the position of the surface light source 101 is taken from an appropriate position, and the evaluation value obtained by the above order is less than 0.6. If so, the image shown in FIG. 7B is obtained. Note that the position at which the surface light source 101 is imaged may be appropriately selected, such as a position equivalent to or near the position of the condensing lens 21 that is the reference for the measurement angle and solid angle in the present embodiment.

  An example of numerical values of various setting items in the optical condensing device 5 is shown. The distance (L-f1) is 300 mm to ∞, the measurement angle 2α is 2 degrees, the diameter of the incident surface 27a of the incident portion 27 is 1 mm, and the incident portion 27. NA (numerical aperture) is 0.2, the focal length f1 of the condenser lens 21 is 80 nm, the front focal length f2 of the relay lens 25 is 100 mm, the rear focal length f3 of the relay lens 25 is 30 mm, and the diameter of the aperture stop 19a. Is 10 mm, the diameter of the field stop 23a is 2.78 mm, and the distance L3 between the condenser lens 21 and the field stop member 23 is 76 to 97 mm. The NA on the exit side of the optical condensing device 5 is set to be smaller than the NA of the incident portion 27.

(Back projection device)
FIG. 8 is a perspective view illustrating the configuration of the back projection device 11. FIG. 9 is an optical path diagram for explaining the back projection device 11.

  As described above, in the optical measurement device 1, the second holding unit 35 (FIG. 3) is moved with respect to the condenser lens 21 according to the change in the measurement distance L, and the field stop member 23 is an image of the condenser lens 21. It is necessary to adjust the focus so that it is positioned on the surface. The back projection device 11 is for facilitating the determination of whether or not the field stop member 23 is positioned on the image plane of the condenser lens 21 (whether or not it is in focus) in this focus adjustment.

  The backprojection device 11 includes a reflective backprojection light source 41 and an insertion mirror 43 that reflects the light emitted from the reflective backprojection light source 41 and causes the light to enter the relay lens 25.

  The reflective backprojection light source 41 emits light having a predetermined cross-sectional shape from the emission surface 41a. In FIG. 8, three examples of the emission surface 41a are shown enlarged. The exit surface 41a_A of the first example can emit light whose cross section is divided into a plurality of rectangles. The exit surface 41a_B of the second example can emit light whose cross section is divided into a plurality of circles. The exit surface 41a_C of the third example can emit light in which a part of the contour of the cross section protrudes inward.

  The exit surface 41a_A of the first example and the exit surface 41a_C of the third example are realized by arranging, for example, a mask 41b formed of a light-shielding thin film on the exit surface. In addition, the emission surface 41 a </ i> _B of the second example includes, for example, the emission part of the reflective backprojection light source 41 including a bundle (multi-core fiber) of a plurality of optical fibers 41 c like the incident part 27. Is realized. Note that the emission surface 41a_B of the second example can also be realized by the mask 41b.

  The insertion mirror 43 can be inserted into and retracted from the optical path between the relay lens 25 and the incident portion 27. The insertion mirror 43 may be inserted and retracted by a slide mechanism or a rotation mechanism, or may be inserted and retracted by being detachable from the second holding unit 35.

  FIG. 10 is an enlarged view of the vicinity of the back projection device 11 of FIG.

  The reflective backprojection light source 41 is disposed at a position where the distance Db between the relay lens 25 and the exit surface 41a is equal to the distance Da between the relay lens 25 and the conjugate point P1. In other words, the insertion mirror 43 moves the conjugate point P1 in a direction different from the direction of the detector 7 (the moved conjugate point is defined as the conjugate point P1 ′), and the emission surface 41a is moved. It is arranged at the conjugate point P1 ′.

  Accordingly, when the image of the exit surface 41a is imaged on the surface light source 101 or the screen disposed at the position of the surface light source 101 via the optical condensing device 5, the position of the surface light source 101 and the field stop member 23 are It will be conjugate. That is, the field stop member 23 is positioned on the image plane of the condenser lens 21. As a result, the operator condenses the field stop member 23 by moving the second holding unit 35 with respect to the first holding unit 33 so as to form an image of the emission surface 41 a at the position of the surface light source 101. It can be positioned on the image plane of the lens 21.

  At this time, the emission surface 41a emits light whose cross section is divided into a plurality of parts, or light whose cross section profile protrudes inward, so that the surface of the light exit surface 41a is compared with the case where the cross section of the light is circular or rectangular. It is easy to determine whether or not an image is formed at the position of the light source 101.

  Such back projection is also effective for grasping the correspondence between the measurement position of the surface light source 101 and the operation amount of the space dividing device 3. For example, when the operator visually recognizes the light from the surface light source 101 via the eyepiece lens at the conjugate point P1 (or P1 ′) without performing back projection, the above-described correspondence relationship is narrowed. It ’s difficult. However, in back projection, since the surface light source 101 is directly visually recognized, it is easy to grasp the above correspondence, for example, to grasp that the measurement region A is located at the end of the surface light source 101. is there.

  Note that back projection is also possible by the method shown in FIG. However, when the back projection device 11 is provided, it is possible to suppress frequent attachment / detachment of the incident portion 27 and the main body portion 29 in order to connect the replacement-type back projection light source 39 instead of the main body portion 29, and as a result It is suppressed that part 27 grade | etc., Breaks. Further, in the method shown in FIG. 6, even if the deviation t between the incident surface 27a and the conjugate point P1 is set appropriately, if the measurement distance L changes thereafter, the incident surface 27a is positioned at the conjugate point P1. In this case, the shift amount t must be set again. However, since the back projection device 11 is provided, the necessity thereof is eliminated, and the shift amount t is maintained.

(Focus adjustment procedure)
The focus adjustment includes a pre-adjustment and a measurement adjustment performed after the pre-adjustment. Specifically, it is as follows.

  FIG. 11 is a flowchart showing a procedure for preliminary adjustment. The pre-adjustment is performed by the manufacturer or the user (optical measurement operator) of the optical measurement device 1. Note that part of the procedure shown in FIG. 11 may be automated.

  In step ST1, as described with reference to FIG. 6, instead of the main body portion 29 of the detector 7, the replacement-type back projection light source 39 is connected to the incident portion 27, and back projection is performed.

  In step ST2, at least one of the condenser lens 21, the field stop member 23, the relay lens 25, and the incident portion 27 is placed on the optical axis so that an image of the incident surface 27a shown in FIG. Move in the direction. That is, both the outline and the inside of the image projected on the position of the surface light source 101 are focused. At this time, not only the movement of the second holding unit 35 relative to the first holding unit 33 but also the field stop member 23, the relay lens 25, and the incident unit 27 may be moved relative to each other. However, the aperture stop 19 is disposed at the front focal point of the condenser lens 21.

  In step ST3, the position of the incident portion 27 is shifted in the optical axis direction. That is, the shift amount t is appropriately set so that the image shown in FIG. 7B is obtained.

  In step ST <b> 4, as described with reference to FIGS. 8 to 10, the insertion mirror 43 is disposed between the relay lens 25 and the incident portion 27.

  In step ST5, light is emitted from the reflective backprojection light source 41, and backprojection is performed via the insertion mirror 43.

  In step ST6, the position of the reflective backprojection light source 41 is adjusted while visually recognizing the image of the exit surface 41a projected onto the position of the surface light source 101, and the image of the exit surface 41a is focused on the position of the surface light source 101. Let Since the field stop member 23 is already arranged at the conjugate point of the surface light source 101 in step ST2, step ST6 combines the inside of the image projected onto the surface light source 101 by the reflective back projection light source 41. Adjustment is made to focus.

  In step ST7, the insertion mirror 43 is retracted from the optical path from the relay lens 25 to the incident portion 27.

  FIG. 12 is a flowchart showing a procedure for adjustment during measurement. It is performed by the user of the optical measuring device 1. A part of the procedure shown in FIG. 12 may be automated. Adjustment at the time of measurement is performed when measurement conditions change, for example, the measurement distance L changes after pre-adjustment.

  Steps ST11 and ST12 are the same as steps ST5 and ST6, and back projection through the insertion mirror 43 is performed as described with reference to FIGS.

  In step ST13, while visually recognizing the image of the emission surface 41a projected on the position of the surface light source 101, the second holding unit 35 is moved with respect to the first holding unit 33, and the image of the emission surface 41a is converted to the surface light source 101. Focus on the position. Note that step ST13 is an adjustment that focuses the contour and the inside of the image projected onto the surface light source 101 from the viewpoint of back projection by the reflective back projection light source 41. That is, the operator performs adjustment so as to focus the outline and the inside of the image. On the other hand, from the viewpoint of detecting light from the surface light source 101 by the detector 7, the incident surface 27a is disposed at a position shifted from the conjugate point P1, and therefore step ST13 refers to FIG. As described above, the adjustment is to blur the inside of the image while focusing the outline of the image.

  Step ST14 is the same as step ST7, and retracts the insertion mirror 43 from the optical path.

  By performing the focus adjustment including the pre-adjustment and the adjustment at the time of measurement, the partial positional relationship between the plurality of optical components, such as the positional relationship between the field stop member 23 and the incident portion 27 obtained by the pre-adjustment, Even if the measurement distance L or the like changes, the adjustment at the time of measurement is not changed and is basically maintained. As a result, for example, as described above, the shift amount t is maintained at a suitable amount, and there is no problem in determining how much the operator should blur. Further, for example, it is not necessary to frequently connect the substitution type back projection light source 39 to the incident portion 27, and the damage of the incident portion 27 is suppressed.

  In the first embodiment described above, the surface light source 101 is an example of the light source to be measured in the present invention, the condenser lens 21 is an example of the first optical system of the present invention, and the relay lens 25 is the present invention. The second holding unit 35 is an example of the holding unit of the present invention, and the galvanometer mirror 13 is an example of the deflection mirror of the present invention.

(Second Embodiment)
FIG. 13 is a plan view showing a schematic configuration of an optical measurement device 201 according to the second embodiment of the present invention. FIG. 14 is an optical path diagram in the optical measurement device 201. Note that in the second embodiment, configurations similar to those in the first embodiment are denoted by the same reference numerals as in the first embodiment, and description thereof is omitted. Further, in FIG. 14, as in FIG. 4, in order to facilitate understanding, the space dividing device is omitted, and the optical components are coaxially arranged.

  The optical measurement device 201 of the second embodiment is different from the optical measurement device 1 of the first embodiment in the configuration of the space dividing device and the optical condensing device. Specifically, it is as follows.

  The space dividing device 203 according to the second embodiment includes two galvanometer mirrors 213 and 214 that can rotate around different axes (for example, axes orthogonal to each other). The galvanometer mirrors 213 and 214 are driven by the first motor 15 and the second motor 17, respectively, and scan the surface light source 101 two-dimensionally.

  The optical condensing device 205 of the second embodiment has a scanning lens 206, and the aperture stop member 19 is not a front focal point of the condensing lens 21 but a conjugate point of the front focal point of the condensing lens 21. The arrangement and the configuration of the relay lens are different from those of the first embodiment.

  The scanning lens 206 is constituted by a lens group, for example. However, the scanning lens 206 may be configured by a single lens. The scanning lens 206 is disposed to face the surface light source 101.

  The scanning lens 206 is configured by a lens that emits light from each part (center part or outer peripheral part) of the surface light source 101 by a predetermined projection method in light of the purpose of measurement. For example, it is as follows.

  If the scanning lens 206 is constituted by a central projection lens represented by y = f · tan θ, the difference in solid angle between the central portion and the outer peripheral portion of the surface light source 101 can be reduced.

  If the scanning lens 206 is configured by a stereoscopic projection lens represented by y = 2f · tan (θ / 2), the difference between the solid angle and the measurement angle between the central portion and the outer peripheral portion of the surface light source 101 can be reduced.

  If the scanning lens 206 is configured by an equidistant projection lens represented by y = f · θ, the difference in measurement area between the central portion and the outer peripheral portion of the surface light source 101 can be reduced.

  Here, y is the distance (object height) between the optical axis LA of the scanning lens 206 and the measurement position on the measurement surface (surface light source 101), f is the focal length of the scanning lens 206, and θ is incident on the space dividing device 203 ( This is the angle (scanning angle) formed by the light beam (emitted from the scanning lens 206) with the optical axis LA.

  The light from the surface light source 101 that has passed through the scanning lens 206 is deflected in a certain direction (the direction of the condensing lens 21) via the space dividing device 203. The deflected light enters the condenser lens 21 and is imaged by the condenser lens 21. The field stop member 23 is disposed at the conjugate point of the surface light source 101 as in the first embodiment. However, in the second embodiment, the field stop member 23 is disposed at the conjugate point of the surface light source 101 via the optical system including the scanning lens 206 and the condenser lens 21.

  The aperture stop member 19 is disposed at the conjugate point of the front focal point of the condenser lens 21. In other words, as shown in FIG. 14, the image 219 of the aperture stop member 19 is located at the front focal point of the condenser lens 21. Therefore, the solid angle of light incident on the condenser lens 21 from the surface light source 101 is defined by the aperture stop 19a. That is, also in the second embodiment, the same effect as that in which the aperture stop member 19 is arranged at the front focal point of the condenser lens 21 as in the first embodiment can be obtained.

  The relay lens includes a first relay lens 225 and a second relay lens 226. For example, the first relay lens 225 and the second relay lens 226 form an afocal system, as in the first embodiment. That is, the first relay lens 225 and the second relay lens 226 are disposed so that the front focal point of the second relay lens 226 is positioned at the rear focal point of the first relay lens 225. 2 The object is imaged at a magnification determined by the ratio of the focal lengths f4 and f5 of the relay lens 226 (see FIG. 14).

  The first relay lens 225 and the second relay lens 226 are arranged so that the front focal point of the first relay lens 225 is positioned on the image plane of the optical system from the scanning lens 206 to the condenser lens 21, for example. An image is formed at the rear focal point of the 2-relay lens 226. The first relay lens 225 and the second relay lens 226 may each be configured by a lens group or may be configured by a single lens.

  The aperture stop member 19 is disposed, for example, at the rear focal point of the first relay lens 225 (the front focal point of the second relay lens 226), and forms a telecentric optical system together with the first relay lens 225 and the second relay lens 226. is doing.

  The incident portion 27 (not shown in FIGS. 13 and 14) of the detector 7 is a conjugate point of the field stop member 23 via the first relay lens 225 and the second relay lens 226 as in the first embodiment. It is arranged at a position deviated from.

  The optical measuring device 201 includes a first holding unit 233 that holds the scanning lens 206, the space dividing device 203, and the condenser lens 21, a field stop member 23, a first relay lens 225, an aperture stop member 19, and a second relay lens 226. And the second holding part 235 that holds the detector 7 (or the incident part 27 of the detector 7), the first holding part 233, and the second holding part 235 in the optical axis direction of the condenser lens 21 (the paper surface of FIG. 1). And a base 237 that can be relatively moved in the left-right direction).

  The material, shape, and movement mechanism of the first holding unit 233, the second holding unit 235, and the base 237 may be appropriately selected. The relative movement of the first holding unit 233 and the second holding unit 235 may be realized by moving either the first holding unit 233 or the second holding unit 235, or by moving both of them. Moreover, it may be driven by human power or may be driven by a driving device such as a motor. The positions of the optical members held by the first holding unit 233 and the optical members held by the second holding unit 35 may be adjustable.

  By moving the second holding unit 235 relative to the first holding unit 233, the field stop member 23 can be positioned on the image plane of the optical system including the scanning lens 206 and the condenser lens 21. At this time, since the first relay lens 225, the aperture stop member 19 and the second relay lens 226 form a telecentric optical system, the second holding portion 235 is moved in the optical axis direction with respect to the first holding portion 233. Even if it is moved, the size of the image 219a (FIG. 14) of the aperture stop 19a does not change.

  According to the second embodiment described above, the same effect as in the first embodiment can be obtained. That is, the optical measurement device 201 is disposed at a conjugate point of the surface light source 101 via the optical system including the scanning lens 206 and the condensing lens 21 that project light from the surface light source 101 as a measurement target. A field stop member 23, an optical system including a first relay lens 225 and a second relay lens 226 that project light from the surface light source 101 that has passed through the field stop member 23, and light projected by the optical system is incident The detector 7 which has the incident part 27 arrange | positioned so that the some incident surface 31a may produce a clearance gap between the said several incident surfaces 31a, and outputs the signal according to the light which injected into the said several incident surface 31a The plurality of incident surfaces 31a are arranged from the conjugate point of the field stop member 23 via the first relay lens 225 and the second relay lens 226 to the first relay lens 225 and the second relay lens. Since it was placed in 226 shifted in the optical axis direction position, as described with reference to FIG. 7 (b), it is possible to suppress the eclipse due to the configuration of the entrance portion 27.

  In the second embodiment described above, the scanning lens 206 and the condenser lens 21 are examples of the first optical system of the present invention, and the first relay lens 225 and the second relay lens 226 are the second optical system of the present invention. It is an example of the system, and the second holding unit 235 is an example of the holding unit of the present invention.

  The present invention is not limited to the above embodiment, and may be implemented in various aspects.

  The optical measurement device and the measurement optical device are not limited to those that scan the light source. For example, light from a point light source may be measured. When the optical measurement device and the measurement optical device are those that scan a light source, the optical measurement device and the scanning optical system are not limited to those that perform two-dimensional scanning, but perform one-dimensional scanning. Also good. In addition, the surface light source to be measured may be a long one that can measure the entire light source only by one-dimensional scanning. The surface light source is not limited to the display device. For example, it may be a surface light source used as illumination or as a backlight of a display device.

  An optical condensing device is not limited to what is comprised by a lens. For example, you may comprise by a curved mirror or the combination of a lens and a curved mirror. When a curved mirror is used, there is an advantage that the angle dependence of the reflection wavelength can be reduced.

  The space dividing device that performs an operation of sequentially taking in light from each part of the surface light source (scanning the surface light source) is not limited to a deflector (deflection mirror) that deflects light from each part of the surface light source in a certain direction. For example, the space dividing device is a moving device that moves an optical condensing device, a detector, or the like along a surface light source, or a rotating device that changes the orientation of the optical condensing device, the detector, or the like with respect to the surface light source. May be.

  The deflector is not limited to a galvanometer mirror. For example, the deflector may be configured to include a polygon mirror. The detector is not limited to a spectrometer. For example, the light may not be dispersed. The amount of light detected by the detector may be a physical quantity or a psychophysical quantity, or may be an amount other than luminance or chromaticity.

  The field stop member may be disposed at the conjugate point of the surface light source via the first optical system (the condensing lens 21 in the first embodiment, the scanning lens 206 and the condensing lens 21 in the second embodiment). Therefore, it may be arranged not at the image plane position of the first optical system but at the conjugate point of the image plane position.

  In the optical measuring device and the scanning optical system, optical elements such as a visibility correction filter, a color filter, and a diffuse transmission plate may be arranged at appropriate positions according to specific circumstances such as the purpose of use and the type of measurement target. . The optical axes of the first optical system and the second optical system may be appropriately bent by a mirror.

  The first embodiment and the second embodiment may be appropriately combined. For example, in the first embodiment, the aperture stop member 19 may be disposed at the conjugate point of the front focal point of the condenser lens 21. In other words, a configuration in which the scanning lens 206 is not provided and a configuration in which the aperture stop member 19 is disposed at the conjugate point of the front focal point of the condenser lens 21 may be combined.

  Further, for example, in the second embodiment, the aperture stop member 19 may be disposed at the front focal point of the condenser lens 21 as in the first embodiment. In other words, the configuration in which the scanning lens 206 is provided and the configuration in which the aperture stop member 19 is disposed at the front focal point of the condenser lens 21 may be combined.

1 is a simplified diagram showing a schematic configuration of an optical measurement device according to a first embodiment of the present invention. The figure explaining the effect | action in the structure of the space division | segmentation apparatus in the optical measuring device of FIG. 1, and arrangement | positioning of another apparatus. The perspective view which shows the principal part of the optical condensing apparatus and detector of the optical measuring device of FIG. The optical path diagram in the optical condensing device and detector of FIG. The figure explaining the effect | action of the optical condensing device of FIG. FIG. 2 is an optical path diagram when substitution-type back projection is performed in the optical measurement apparatus of FIG. 1. The figure explaining the effect | action of the positional relationship of the optical condensing device of FIG. 3, and a detector. The perspective view explaining the structure of the back projection apparatus of the optical measuring device of FIG. FIG. 9 is an optical path diagram illustrating the back projection device of FIG. 8. FIG. 10 is an enlarged view of the vicinity of the back projection device in the optical path diagram of FIG. 9. 3 is a flowchart showing a procedure for pre-adjustment of focus adjustment in the optical measurement device of FIG. 1. 3 is a flowchart showing a procedure for adjustment at the time of focus adjustment in the optical measurement device of FIG. 1. FIG. 6 is a simplified diagram showing a schematic configuration of an optical measurement device according to a second embodiment of the present invention. FIG. 14 is an optical path diagram in the optical measurement device of FIG. 13.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical measuring device, 7 ... Detector, 21 ... Condensing lens (1st optical system), 23 ... Field stop member, 25 ... Relay lens (2nd optical system), 27 ... Incident part, 31a ... Incident surface, 101: Surface light source (light source to be measured).

Claims (10)

A first optical system that projects light from a light source to be measured as a measurement target;
A field stop member disposed at a conjugate point of the light source to be measured via the first optical system;
A second optical system that projects light from the light source to be measured that has passed through the field stop member;
According to the light incident on the plurality of incident surfaces, the plurality of incident surfaces on which the light projected by the second optical system is incident have an incident portion arranged such that gaps are generated between the plurality of incident surfaces. A detector that outputs
Have
The plurality of incident surfaces are arranged at positions shifted from a conjugate point of the field stop member via the second optical system in the optical axis direction of the second optical system. The holding | maintenance part which hold | maintains the said field stop member, the said 2nd optical system, and the said incident part, and can move to the optical axis direction of the said 1st optical system with respect to the said 1st optical system. Optical measuring device. An insertion mirror inserted between the second optical system and the detector and capable of disposing a conjugate point of the field stop member via the second optical system in a direction different from the direction of the detector;
A reflective backprojection light source arranged at a conjugate point arranged by the insertion mirror and capable of emitting light to the insertion mirror;
The optical measurement device according to claim 1, comprising: The optical measurement device according to claim 3, wherein the light source for reflection back projection is capable of emitting light having a cross section divided into a plurality of parts, or light in which a part of a cross section outline protrudes inward. The optical measurement apparatus according to claim 4, wherein the reflective backprojection light source has a mask for shaping a light cross section at a conjugate point arranged by the insertion mirror. The optical measurement apparatus according to claim 4, wherein the reflective backprojection light source includes a plurality of optical fibers that have a plurality of emission surfaces that emit light and are positioned at conjugate points arranged by the insertion mirror. The light source to be measured is a surface light source having an emission surface having a longitudinal direction and a short direction perpendicular to the longitudinal direction,
A deflecting mirror that is movable so as to sequentially reflect light from each part of the surface light source toward the first optical system;
The first optical system includes:
A position closer to the surface light source than the deflection mirror,
In the longitudinal direction, a position closer to the center of the surface light source than the optical path from the longitudinal end of the surface light source to the deflection mirror, and
The optical measurement device according to claim 1, wherein in the short direction, the light measuring device is disposed at a position outside the surface light source with respect to an optical path from the short direction end of the surface light source to the deflection mirror. The optical measurement device according to claim 1, further comprising an aperture stop member disposed at a front focal point of the first school system or a conjugate point of the front focal point. A first optical system that projects light from a light source to be measured as a measurement target;
A field stop member disposed at a conjugate point of the light source to be measured via the first optical system;
A second optical system for projecting light from the light source to be measured that has passed through the field stop member;
A plurality of incident surfaces on which light projected by the second optical system is incident are disposed so that gaps are formed between the plurality of incident surfaces; and the light guided by the incident unit is received. A detector having a main body that outputs a signal corresponding to the received light, and the incident part, and
A replacement type back projection light source connected to the incident part instead of the main body part and capable of emitting light from the plurality of incident surfaces,
And place
At least one of the first optical system, the field stop member, the second optical system, and the incident portion, which are arranged, is moved, and the image of the field stop member and the plurality of incident surfaces are captured. Focus on the location of the measurement light source,
After the in-focus, move the incident portion, defocus images of the plurality of incident surfaces at the arrangement position of the light source to be measured,
After the defocusing, the focus adjustment method of the optical measurement device, wherein the main body portion is connected to the incident portion instead of the replacement type back projection light source. After connecting the main body portion to the incident portion, an insertion mirror is inserted between the second optical system and the detector, and a conjugate point of the field stop member via the second optical system is detected by the detector. Placed in a different direction from
The light from the reflective backprojection light source arranged at the conjugate point arranged by the insertion mirror is reflected by the insertion mirror and projected to the position of the light source to be measured,
The field stop member, in the optical axis direction of the first optical system, with respect to the first optical system, so that the image of the reflection type backprojection light source is focused on the position of the light source to be measured. The focus adjustment method of the optical measuring device according to claim 9, wherein the second optical system and the incident portion are moved integrally.

Images