JP7206736B2 - Measuring device and measuring method - Google Patents

Description

The present invention relates to a measuring device and a measuring method.

In Patent Document 1, a plurality of light-emitting panels that are arranged in a plane and emit light from a light-emitting surface toward the front side, and a light-emitting panel extending along the outer edge of the adjacent light-emitting panel among the plurality of light-emitting panels. a light amount correction member having a reflecting surface that reflects part of the light emitted from the light emitting surface toward the front side, and a plurality of light emitting panels and the light amount correction member that face the plurality of light emitting panels and the light amount correction member with a gap therebetween. and a light diffusing member that diffuses the light emitted from the light emitting surface and the light reflected by the reflecting surface, and the reflecting surface emits light from the light emitting surface toward the outer edge of the light emitting panel. The reflective surface has a shape extending in a direction away from the surface, and the reflective surface has a first reflective area and a reflectance that is located closer to the light emitting surface than the first reflective area and has a higher reflectance than the first reflective area. A surface emitting unit is disclosed that includes a second reflective area.

Patent Document 2 discloses a liquid crystal display element having a liquid crystal layer sandwiched between two transparent substrates, a backlight for illuminating the liquid crystal display element from behind, and a light diffusion device provided between the liquid crystal display element and the backlight. A light guide plate comprising a plate, wherein the backlight is formed of a transparent plate having a dot print pattern for improving reflectance on the opposite side of the light emitting surface, and a linear light guide plate provided along at least one side of the light guide plate A liquid crystal display device is disclosed which has a lamp and a reflector placed on the back of a light guide plate, and is characterized in that the dot print pattern of the light guide plate is a chromatic color.

In Patent Document 3, a light projecting means for irradiating light onto agricultural products, a first light guide means for guiding detection light emitted from the light projecting means and transmitted or reflected by the agricultural products, and light emitted from the light projecting means The second light guiding means having an optical axis different from that of the first light guiding means and the detection light guided by the first light guiding means or the reference light guided by the second light guiding means are guided as reference light. Selecting means for optionally passing or shielding, and spectroscopic analysis means for analyzing or calibrating the detected light passed by the selecting means with reference light, In the apparatus for measuring the internal quality of agricultural products capable of measuring the internal quality of agricultural products, the selection means includes a diffusion plate that guides the reference light guided by the second light guide means to the optical axis of the first light guide means while diffusely reflecting the reference light inside. An apparatus for measuring the internal quality of produce is disclosed, comprising:

JP 2014-203675 A JP-A-2000-321570 JP 2008-298466 A

An object of the present invention is to suppress omission and leakage of the amount of light received by a light receiving element in a measurement apparatus using a telecentric optical system, compared to a case in which no scattering means is arranged between a lens and an object. It is to provide a possible measuring device and measuring method.

In order to achieve the above object, a measuring device according to a first aspect includes a light emitting unit that emits irradiation light to irradiate an object, and a first lens that changes the degree of divergence of the irradiation light emitted from the light emitting unit. a diaphragm for narrowing the irradiation light emitted from the first lens; and a second lens for condensing the irradiation light that has passed through the diaphragm so as to irradiate the object from a predetermined direction. a lens, a light-receiving unit arranged between the aperture unit and the second lens for receiving reflected light reflected by the object when the irradiation light is irradiated, the second lens and the object and scattering means for scattering the irradiation light and the reflected light, wherein the irradiation light is scattered by the scattering means and irradiated to the object, and the reflected light is scattered by the scattering means The light is scattered and received by the light receiving section.

A measuring device according to a second aspect is the measuring device according to the first aspect, wherein the scattering means is a diffusion plate.

A measuring device according to a third aspect is the measuring device according to the first aspect or the second aspect, wherein the scattering means is such that the distance from the object is the distance between the second lens and the object. is arranged at a position that is less than or equal to 1/2 of .

A measuring device according to a fourth aspect is the measuring device according to the third aspect, wherein the scattering means has a distance from the object that is 1/10 or more of the distance between the second lens and the object. It is placed at a position where

A measuring device according to a fifth aspect is the measuring device according to the first aspect or the second aspect, wherein the scattering means is formed on the object-side surface of the second lens.

A measuring device according to a sixth aspect is the measuring device according to the fifth aspect, wherein the scattering means is formed integrally with the second lens.

A measuring device according to a seventh aspect is the measuring device according to any one of the first aspect to the fourth aspect, wherein the scattering means can be held at a plurality of different positions in the optical axis direction of the second lens. Further including retaining means.

A measuring device according to an eighth aspect is the measuring device according to any one of the first aspect to the fourth aspect and the seventh aspect, wherein the scattering means is arranged along the optical axis direction of the second lens. It is further provided with a moving means for moving by pressing.

A measuring device according to a ninth aspect is the measuring device according to any one of the first aspect to the fourth aspect, the seventh aspect, and the eighth aspect, wherein the scattering means is the second lens and the It further comprises an extracting means for extracting from between the object.

A measuring device according to a tenth aspect is the measuring device according to any one of the first to ninth aspects, wherein the distance between the light receiving surface of the light receiving unit and the second lens is the distance of the second lens. It is made equal to the focal length.

A measuring device according to an eleventh aspect is the measuring device according to the tenth aspect, wherein the distance between the first lens and the diaphragm is equal to the focal length of the first lens.

In order to achieve the above object, a measurement method according to a twelfth aspect includes a light emitting unit that emits irradiation light to irradiate an object, a first lens that changes the degree of divergence of the irradiation light emitted from the light emitting unit, a diaphragm that narrows down the irradiation light emitted from the first lens; a second lens that collects the irradiation light that has passed through the diaphragm so as to irradiate the object from a predetermined direction; a light-receiving unit disposed between the aperture unit and the second lens and receiving reflected light reflected by the irradiation light applied to the object; and between the second lens and the object. A measurement method using a measuring device including a scattering means disposed and arranged to scatter the irradiation light and the reflected light, wherein the irradiation light is scattered by the scattering means and irradiated onto the object, and the reflected light is irradiated to the object. The light is scattered by the scattering means and received by the light receiving section to measure the surface state of the object.

A measuring method according to a thirteenth aspect is the measuring method according to the twelfth aspect, wherein the surface state of the object is measured by changing the scattering means according to the object.

A measuring device according to a fourteenth aspect is the measuring device according to the thirteenth aspect, wherein a plurality of measuring devices each including the different scattering means are provided, and one of the plurality of measuring devices is selected according to the object. It is measured by

A measuring device according to a fifteenth aspect is the measuring device according to the fourteenth aspect, wherein one of the plurality of measuring devices does not include the scattering means.

According to the measurement device of the first aspect and the measurement method of the twelfth aspect, in the measurement device using the telecentric optical system, compared with the case where the scattering means is not arranged between the lens and the object, It is possible to obtain the effect of providing a measuring device and a measuring method capable of suppressing omission or leakage of the amount of light received by the element.

According to the measuring device of the second aspect, compared with the case where the scattering means is something other than the diffusion plate, it is possible to obtain the effect that the scattered light with the desired scattering angle can be easily obtained.

According to the measurement device of the third aspect, compared to the case where the scattering means is arranged at a position where the distance from the object exceeds 1/2 of the distance between the second lens and the object, It is possible to obtain the effect of suppressing the divergence angle of the scattered light from becoming excessive.

According to the measurement device of the fourth aspect, compared to the case where the scattering means is arranged at a position where the distance from the object is less than 1/10 of the distance between the second lens and the object , it is possible to prevent the desired scattering effect from being obtained.

According to the measuring device of the fifth mode, compared with the case where the scattering means is provided independently of the second lens, the effect of facilitating the handling of the scattering means can be obtained.

According to the measuring device of the sixth aspect, it is possible to obtain the effect that the scattering means is easier to manufacture than when the scattering means is formed separately from the second lens.

According to the measuring device of the seventh aspect, the position of the scattering means in the optical axis direction is higher than the case where the holding means capable of holding the scattering means at a plurality of positions different in the optical axis direction of the second lens is not included. can be easily adjusted.

According to the measuring device of the eighth aspect, fine adjustment of the position of the scattering means in the direction of the optical axis is possible compared to the case where the moving means for moving the scattering means along the optical axis direction of the second lens is not provided. The effect of being easily performed is obtained.

According to the measuring device of the ninth aspect, compared with the case where the removing means for removing the scattering means from between the second lens and the object is not provided, the degree of specular reflection of the reflected light from the object It is possible to obtain the effect of making it possible to measure

According to the measuring device of the tenth aspect, the optical system is a one-side telecentric optical system, compared to the case where the distance between the light receiving surface of the light receiving unit and the second lens is not equal to the focal length of the second lens. You can get the effect of

According to the measuring device of the eleventh aspect, the optical system is a double-telecentric optical system, compared to the case where the distance between the first lens and the diaphragm is not equal to the focal length of the first lens. effect is obtained.

According to the measuring device of the thirteenth aspect, the degree of scattering is selected according to the surface state of the object, compared to the case where the surface state of the object is measured without changing the scattering means even if the object changes. It is possible to obtain the effect of

According to the measuring device of the fourteenth aspect, the measuring device is selected according to the surface state of the object, compared to the case of measuring with a measuring device including a fixed scattering means even if the object changes. effect is obtained.

According to the measuring device of the fifteenth aspect, it is possible to obtain the effect that the reflected light without the scattering means can be easily confirmed as compared with the case where all of the plurality of measuring devices include the scattering means.

BRIEF DESCRIPTION OF THE DRAWINGS It is a side view which shows an example of a structure of the measuring device which concerns on 1st Embodiment. It is a figure explaining operation|movement when there is no diffusion plate of the measuring device which concerns on 1st Embodiment. (a) is a diagram for explaining the measurement principle of the measurement apparatus according to the first embodiment, and (b) is a diagram for explaining a comparison of output distributions of light receiving elements. It is a figure explaining operation|movement of the measuring device which concerns on 1st Embodiment. It is a figure explaining the position of the diffusion plate of the measuring device concerning a 1st embodiment. It is a figure explaining arrangement|positioning of the diffusion plate of the measuring device which concerns on 1st Embodiment. It is a side view which shows an example of a structure of the measuring device which concerns on 2nd Embodiment. It is a side view which shows an example of a structure of the measuring device based on the modification of 2nd Embodiment. It is a figure explaining the characteristic of the measuring device concerning a comparative example.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[First embodiment]
A measuring apparatus and a measuring method according to the present embodiment will be described in detail with reference to FIGS. 1 to 6. FIG. First, with reference to FIG. 1, an example of the configuration of a measurement device 10 according to this embodiment will be described. FIG. 1 shows a configuration for measuring an object using a measuring device 10. As shown in FIG.

As shown in FIG. 1, the measuring device 10 includes a light emitter 14, an optical system 30, a light receiver 18, a diffuser plate 60 and a controller 20. As shown in FIG. The measuring device 10 sequentially irradiates light from the Z-axis direction to a fine region of the object OB moving in the -X direction, and acquires the reflection angle distribution of the reflected light for each irradiation light (reflection angle dependence of the light amount distribution). . Using the acquired reflection angle distribution, changes in the shape of the object OB and surface conditions (texture, emboss, surface roughness, surface defects, adhesion of foreign matter, etc.) can be analyzed. Measurements are made without being affected by

More specifically, as shown in FIG. 1, the light emitter 14 is arranged above the measurement region T through which the object OB moving in the -X direction passes in the vertical direction of the apparatus (Z-axis direction). there is The light emitter 14 includes a plurality of light emitting elements 12 mounted side by side in the Y-axis direction on the substrate 14A and emitting light in the -Z direction. In other words, the plurality of light emitting elements 12 are arranged in a direction orthogonal (crossing) to the movement direction (−X direction) of the object OB. In FIG. 1, the light emitting element 12 arranged at one end of the substrate 14A in the Y-axis direction (right end in the drawing) is referred to as the light emitting element 12A, and the other end of the substrate 14A in the Y-axis direction (left end in the drawing) has a light emitting element 12A. The arranged light emitting element 12 is denoted as light emitting element 12B, and the light emitting element 12 arranged in the center of substrate 14A is denoted as light emitting element 12C.

The plurality of light emitting elements 12 according to the present embodiment are configured to sequentially emit light from the light emitting elements 12A to 12B with a time difference, and the light from each light emitting element 12 is directed to different positions on the object OB. Individually irradiated. While the object OB moves in the -X direction in the measurement area T, one cycle of light emission from the light emitting elements 12A to 12B is repeated multiple times.

Although the light emitting element 12 is not particularly limited, as an example, a vertical cavity surface emitting laser (VCSEL), a light emitting diode (LED), or the like is used.

The optical system 30 includes a lens 32, a lens 34, and a diaphragm 40 arranged between the lenses 32 and 34, and is configured as a so-called double-telecentric lens. The optical system 30 is arranged between the light emitter 14 and the object OB, guides the irradiation light emitted from the light emitting element 12 to the object OB, and transmits the reflected light reflected by the object OB to the light receiver 18. lead.
In other words, the light receiver 18 is configured to receive at least part of the light flux that is emitted from the lens 34 and is reflected by the object OB and transmitted through the lens 34 again. Further, in this embodiment, the optical axis of the lens 32 and the optical axis of the lens 34 are a common optical axis M. through the center of the opening 42 of the . In the present embodiment, a form in which the optical system 30 is configured as a double-telecentric lens will be described as an example. However, the present invention is not limited to this. It may be configured as a lens.

The lens 32 is, for example, a circular plano-convex lens in plan view, and the diameter of the lens 32 is longer than the dimension in the Y-axis direction from the light emitting element 12A to the light emitting element 12B. Therefore, almost all of the light emitted from each light emitting element 12 passes through the lens 32 , and the light that has passed through the lens 32 has its degree of divergence changed and is turned into parallel light and directed to the lens 34 .

The lens 34 is, for example, a circular plano-convex lens in plan view, and in the present embodiment, the diameter of the lens 34 is longer than the diameter of the lens 32 . Then, the lens 34 converges the light beam emitted from the lens 32 and transmitted through the lens 34 toward the surface 200 of the object OB.

A substantially circular opening 42 is formed in the diaphragm 40 , and this opening 42 narrows the light beam emitted from the light emitting element 12 and transmitted through the lens 32 to enter the lens 34 . More specifically, the diaphragm 40 has a plate-like shape with its plate surface parallel to the XY plane, and the circular shape formed by the aperture 42 has the optical axis M as its central axis. In the Z-axis direction, the distance between the opening 42 and the lens 32 is substantially equal to the focal length of the lens 32, and the distance between the opening 42 and the lens 34 is substantially equal to the focal length of the lens 34. there is The relationship between the arrangement of the aperture 42, the lens 32, and the lens 34 and the focal lengths of the lenses 32 and 34 is a condition for making the optical system 30 a double-telecentric optical system. However, this distance relationship should be determined according to the required function (performance) of the telecentric optical system, and strictness is not required. is not a problem either.

The control unit 20 includes a CPU, ROM, RAM, etc. (not shown), and controls the timing of light emission by the light emitting element 12 and the timing of capturing the amount of light received by the light receiving element 16 . The control unit 20 may also control the movement of the diffusion plate 60, which will be described later, and the position adjustment of the diffusion plate 60 in some cases.

The measurement device 10 further includes a diffuser plate 60 . As shown in FIG. 1, the diffusion plate 60 according to this embodiment is arranged so that it can be inserted and removed between the lens 34 and the object OB. That is, the diffuser plate 60 is configured to rotate around the rotation axis C, and is configured to be able to be put in and taken out between the lens 34 and the object OB. Details of the diffusion plate 60 will be described later.

Next, operation of the measuring device 10 will be described with reference to FIG. FIG. 2 shows the illumination of the object OB with the illumination light IF from the light emitter 14 and the incidence of the reflected light RF from the object OB on the light receiving element 16 . In FIG. 2, illustration of the diffusion plate 60 is omitted so that the irradiation light IF and the reflected light RF can be easily understood. The light-emitting elements 12 mounted on the light-emitting device 14 sequentially emit light in the -Y direction, for example. The optical system 30 sequentially irradiates the object OB in the +Y direction with the luminous fluxes from the light emitting elements 12 that are sequentially emitted as irradiation light IF that is narrowed and parallel to the optical axis M regardless of the positions of the light emitting elements 12. do. 2A shows a state in which the first light emitting element 12 out of the plurality of light emitting elements 12 emits light, and FIG. 2B shows a state in which the second light emitting element 12 out of the plurality of light emitting elements 12 emits light. FIG. 2C shows the state in which the n-th light emitting element 12 among the plurality of light emitting elements 12 emits light.

As shown in FIGS. 2(a) to 2(c), each light-emitting element 12 is caused to emit light for scanning, so that the object OB is individually irradiated with light beams (spots) that are narrowly focused and substantially parallel to each other and substantially circular. Furthermore, in the measurement apparatus 10 according to the present embodiment, by arranging the object OB in the vicinity of the condensing point of the luminous flux of the irradiation light IF by the lens 34, the irradiation areas of the irradiation light IF on the object OB are substantially the same. It is defined as a fine-diameter region. As a result, even if the position of the object OB fluctuates up and down in the Z-axis direction, the measurement apparatus 10 irradiates each irradiation light beam with substantially the same irradiation diameter, so that blurring of the image of the object OB is extremely reduced. be. At this time, the irradiation light IF passes through the diffuser plate 60, and the action of the diffuser plate 60 will be described later.

The light receiver 18 includes a plurality of light receiving elements 16 and receives the reflected light RF that has been reflected by the object OB and transmitted through the lens 34 of the optical system 30 . That is, as shown in FIGS. 2A to 2C, the object OB is sequentially irradiated with the irradiation light IF from each of the light emitting elements 12, and is reflected to generate the reflected light RF. The irradiation light IF is reflected in various directions depending on the state of the surface 200 of the object OB. It receives the reflected light RF within an angle range of 0° to 60° about the axis. Therefore, the light receiving area of the light receiver 18 corresponding to the irradiation light IF emitted from one light emitting element 12 is substantially circular. The reflected light RF having the same reflection angle is received by the same light receiving element 16 regardless of the position of the object OB in the Z-axis direction. Through the above operations, the measurement apparatus 10 measures each reflection intensity distribution at a plurality of irradiation points on the object OB. The photodetector 18 according to the present embodiment is arranged below the stop 40 arranged between the lens 32 and the lens 34 in the Z-axis direction. is the same as the position of The light-receiving element 16 is not particularly limited, but for example, a photodiode (PD), a charge-coupled device (CCD), or the like is used. In this embodiment, the "angle of reflection" is measured with reference to the Z-axis direction (0 degrees).

Although the number of light receiving elements 16 in the light receiver 18 is not particularly limited, the number is 32 as an example in the present embodiment. As an example, the 32 light receiving elements 16 are arranged in a line across the aperture 42 of the diaphragm 40 . On the other hand, the number of light-emitting elements 12 in the light-emitting device 14 is not particularly limited, but is set to 250 as an example in the present embodiment. That is, when measuring the object OB, 32 received light amounts are obtained by the irradiation light IF from one light emitting element 12 . Therefore, 250 irradiation light IFs are emitted in one scan while the object OB moves in the measurement region T, and 32 received light amounts are acquired by the reflected light RF for each irradiation light IF.

Here, one characteristic of the measuring device 100 according to the comparative example will be described with reference to FIG. 9 . In the measurement apparatus 100 according to the comparative example using the telecentric optical system, when specularly reflected light is dominant in the reflected light RF from the object OB, most of the reflected light RF passes through the aperture 42 of the diaphragm 40. Therefore, there were cases where a sufficient amount of light could not be received. Specularly reflected light is dominant, for example, when the surface of the object OB is close to a mirror surface. This state is illustrated in FIG. 9(a). That is, in the reflected light RF that is reflected by the object OB irradiated with the irradiation light IF, if specular reflected light, that is, reflected light with a reflection angle of about 0 degrees is dominant, most of the reflected light RF is passes through the opening 42 and returns toward the lens 32 . In this case, the reflected light RF hardly enters the light receiving element 16 .

As one method for preventing the reflected light RF from going to the opening 42, the object OB is tilted as shown in FIG. It is conceivable to convert the direction to the direction of the light receiving element 16 . However, in this case, the reflected light RF whose light intensity is concentrated in a narrow range centered on the optical axis is incident on a specific light receiving element 16, so that the light receiving element 16 may be saturated. When the light-receiving element 16 is saturated, it is of course impossible to compare the amount of reflected light or the reflectance between different objects OB. Alternatively, even if the object OB is tilted, if the object OB has unevenness 70 as shown in FIG. It is conceivable that the light will pass through the opening 42 as well.

Therefore, in the present invention, a scattering means (diffusion plate 60) is arranged between the lens 34 and the object OB. As a result, the irradiation light IF and the reflected light RF become light in a state close to perfect diffusion. Therefore, leakage of the amount of light received by the light receiving element is suppressed.

The measurement principle of the measurement device 10 will be described with reference to FIG. FIG. 3(a) shows the configuration of the measuring device 10 when the diffusion plate 60 is arranged. As shown in FIG. 3A, the diffuser plate 60 diffuses the irradiation light IF and irradiates the object OB. In this embodiment, a transmissive diffuser plate having characteristics close to perfect diffusion is used as the diffuser plate 60 . Therefore, the irradiation light IF emitted from the diffuser plate 60 spreads isotropically, and the object OB is irradiated with the irradiation light IF having substantially the same intensity regardless of the direction. Although the form of the diffusion plate 60 is not particularly limited, for example, it is preferable that the diffusion plate 60 has microlens-like irregularities formed on the surface of the base material. From the viewpoint of measurement accuracy, it is preferable that the unevenness is smaller than the spot size of the irradiation light IF.

On the other hand, the reflected light RF generated when the object OB is irradiated with the irradiation light IF is also diffused by passing through the diffusion plate 60 . As the reflected light IF is diffused, it is dispersed and received by the plurality of light receiving elements 16 . Due to the action of the diffuser plate described above, even if the specularly reflected light is dominant in the reflected light RF from the object OB, the diffusely reflected light is substantially uniform in many directions. As a result, almost all of the reflected light RF is not directed toward the aperture 42 of the diaphragm 40, and is received by the plurality of light receiving elements 16 in a dispersed manner. At the same time, saturation of the light receiving element 16 is also suppressed. Therefore, it is possible to easily compare the amount of reflected light or the reflectance between the objects OB having large amounts of specularly reflected light.

FIG. 4 shows the operation of the measuring device 10 according to the present embodiment corresponding to the operation of the measuring device according to the comparative example shown in FIG. Since the diffusion plate 60 is arranged in the measurement apparatus 10, the irradiation light IF and the reflected light RF are diffused in both cases, and the reflected light RF, which is dominated by specularly reflected light having a large light intensity in a specific direction, is Almost uniform diffusely reflected light in multiple directions is obtained. Although FIG. 4 shows the irradiation light IF from one specific light emitting element 12, the irradiation light IF from other light emitting elements 12 is the same. That is, although the irradiation point (reflection point) of the irradiation light IF differs depending on the light emitting element 12, the light receiving element 16 is arranged on the focal plane of the lens 34 in the measurement apparatus 10, so the irradiation point (reflection point) is X The light is received by the light-receiving element 16 corresponding to the reflection angle at any position in the -Y plane.

Next, with reference to FIG. 3B, a comparison of the output distribution (reflectance comparison) of the light receiving element 16 in the measuring device 10 according to the present embodiment will be described. FIG. 3(b) shows the reflection angle dependence (hereinafter referred to as "light intensity characteristic") of the amount of received light (denoted as "light intensity" in FIG. 3(b)). That is, the horizontal axis represents the reflection angle in the positive direction (+) and the negative direction (-) with 0 degrees as the center, and the vertical axis represents the light intensity on an arbitrary scale. Since the angle of reflection corresponds to the light receiving element 16 (in other words, reflected light with the same angle of reflection is received by the same light receiving element 16), the horizontal axis may be considered as the position of the light receiving element 16. FIG. FIG. 3(b) shows the light intensity characteristics of three objects OB indicated by curves C1, C2 and C3, respectively. When comparing these light intensity characteristics, the light intensity at a specific angle θ may be compared, or the light intensity at a specific angle range may be compared. Furthermore, the integrated value of the total reflection angle range of the characteristics shown in FIG. 3(b) may be used for comparison. Although the range of reflection angles that can receive light affects the size of the measurement apparatus 10 in the Y-axis direction, in the present embodiment, as described above, the range is −60 degrees <θ<+60 degrees as an example. .

Next, the position of the diffusion plate 60 in the Z-axis direction in the measuring device 10 will be described with reference to FIG. Due to the properties of the diffuser plate 60, the spot size of the irradiation light IF increases as the position of the diffuser plate 60 in the Z-axis direction in FIG. 5 moves away from the object OB. Although the spot size of the irradiation light IF is made somewhat larger than the case without the diffuser plate in accordance with the gist of the measurement apparatus 10 according to the present embodiment, there is a possibility that the measurement accuracy will drop if the spot size becomes larger than necessary. Therefore, in principle, it is desirable to dispose the diffusion plate 60 close to the object OB. For example, the diffuser plate 60 may be arranged at a position that is less than half the distance between the lens 34 and the object OB. In this case, the scattering effect of bringing the diffusion plate 60 closer to the object OB than necessary is reduced, so the diffusion plate 60 may be arranged at a position that is, for example, 1/10 or more of the distance between the lens 34 and the object OB.

Setting the position of the diffusion plate 60 in the Z-axis direction will be described in more detail. From the properties of the diffuser plate 60 described above, it is preferable to set the position of the diffuser plate 60 in the Z-axis direction in consideration of the spot size, the spread range of the diffused reflected light RF, and the like. For example, an upper limit may be set for the spot size, and the position of the diffuser plate 60 on the Z axis may be set so that the required divergence angle of the reflected light RF can be obtained within the range of the spot size. Alternatively, conversely, an upper limit may be set for the spread angle of the reflected light RF. By arranging the diffuser plate 60 as close to the object OB as possible based on the concept described above, the diffusion of the irradiation light IF can be suppressed to a necessary minimum and the size of the irradiation spot can be prevented from becoming larger than necessary. In addition, most of the reflected light RF is suppressed from going to the opening 42 of the diaphragm 40, and is received by the plurality of light receiving elements 16 in a dispersed manner, so that the saturation of the output of the light receiving elements 16 is also suppressed.

Here, the specific size of the spot size of the irradiation light IF is, for example, in the range of 10 μm to 100 μm before incidence on the diffuser plate 60 . By setting the spot size to a value within this range, the inside of the object OB or the inside of the object can be measured with high spatial resolution. Therefore, by arranging the diffuser plate 60 close to the object OB as shown in FIG. 5, the diffusion of the irradiation light IF can be suppressed to the necessary minimum, and the in-plane variation of the reflectance of the object OB can also be evaluated. be.

FIG. 6 shows various configurations of the position of the diffuser plate 60. FIG. FIG. 6A shows the state of the irradiated light IF and the reflected light RF when the diffusion plate 60 is arranged close to the object OB, and FIG. The states of the irradiated light IF and the reflected light RF are respectively shown when they are arranged in the same direction. Further, the diffuser plate 60 associated with the measuring apparatus 10 is configured not only to move in the Z-axis direction, but also to be removed from between the lens 34 and the object OB as shown in FIG. 6(c). . The function of removing the diffuser plate 60 is used, for example, to confirm the properties of the reflected light RF. In other words, when the measurement apparatus 10 is normally used without the diffuser plate 60, insert the diffuser plate 60 when a phenomenon such as an abnormally small output signal from the light receiver 18 occurs. In this case, if the cause is excessive specularly reflected light, the output signal is normally output from the photodetector 18, so the cause of the output abnormality of the photodetector 18 can be quickly grasped.

[Second embodiment]
A measuring device 10A according to the present embodiment will be described with reference to FIG. The measurement device 10A has a configuration in which holding means for the diffusion plate 60 is added to the measurement device 10 according to the above embodiment.
Therefore, the same reference numerals are assigned to the same configurations as those of the measuring device 10, and detailed description thereof will be omitted.

As shown in FIG. 7A, the measuring device 10A has holding means 62 for the diffusion plate 60. As shown in FIG. The holding means 62 has a plurality of slots 66 and is configured such that the position of the diffusion plate 60 in the Z-axis direction is set by inserting the diffusion plate 60 into one of the slots 66 . The shape of the holding means 62 in a plan view may be a bar shape with the slots 66 arranged linearly, or a U-shape with the slots 66 arranged on three sides.

FIG. 7(a) shows the diffusion plate 60 inserted into the slot 66 closest to the object OB, and FIG. 7(b) shows the diffusion plate 60 inserted into the slot 66 farthest from the object OB. state. 7(c) shows a state in which the diffusion plate 60 is removed from the holding means 62. FIG. Thus, according to the measuring device 10A according to the present embodiment, the position of the diffusion plate 60 can be freely set.

<Modification of Second Embodiment>
A measuring device 10B according to a modification of the second embodiment will be described with reference to FIG.
In the measurement apparatus 10A according to the above embodiment, the position of the diffuser plate 60 is manually set. In this form, the position is automatically changed. Therefore, configurations similar to those of the measurement apparatus 10A are denoted by the same reference numerals, and detailed description thereof is omitted.

The measuring device 10B includes moving means 64 for the diffusion plate 60, as shown in FIG. The moving means 64 clamps the diffusion plate 60, moves the clamped diffusion plate 60 in the Z-axis direction as shown in FIGS. I do. Alternatively, the diffusion plate 60 is removed from the optical path as shown in FIG. 8(c). According to this modification, the position of the diffusion plate 60 is automatically set.

Here, a measuring method using the measuring apparatus (10, 10A, 10B) according to each of the above embodiments will be described. The measuring device (10, 10A, 10B) according to the present invention is also used, for example, as an inspection device in the manufacturing process. That is, for example, the product may be inspected by measuring the surface state or the internal scattering state of the object OB (product). In this case, for example, a measurement device such as the measurement device 10B in which the diffusion plate 60 is automatically positioned or inserted/removed is used.

In the inspection using the measurement devices (10, 10A, 10B), the scattering plate 60 may be changed according to the object OB, for example, in consideration of the size of the specularly reflected light component of the object OB. Alternatively, a plurality of measurement devices (10, 10A, 10B) may be installed, and measurement may be performed by selecting one of the measurement devices (10, 10A, 10B) according to the object OB. In that case, for example, at least one of the plurality of measuring devices (10, 10A, 10B) may be the measuring device (10, 10A, 10B) without the scattering plate 60 (or removed from the optical path). This facilitates measurement even when the received reflected light RF contains various specularly reflected light components.

In each of the above-described embodiments, the form in which the diffuser plate 60 is arranged independently has been exemplified and explained, but the present invention is not limited to this. For example, it may be arranged integrally with the lens 34 . That is, for example, the surface of the lens 34 on the object OB side may be processed so as to scatter light, and a diffuser plate may be arranged. In this case, a sheet-like diffuser plate separate from the lens 34 may be attached to the lens 34 to dispose the diffuser plate, or the lens 34 itself may be unevenly processed to dispose the diffuser plate.

Further, in each of the above-described embodiments, a configuration in which the diffuser plate 60 is inserted into the irradiation light IF of all the light emitting elements 12 has been described as an example, but the present invention is not limited to this. The diffuser plate 60 may be inserted into some of the plurality of light emitting elements 12, for example half of them, and not inserted into the other half. According to such a configuration, a single measurement device can grasp the difference in the reflection characteristics on the surface of the object OB due to the difference in the degree of diffusion of the irradiation light IF.

Further, in each of the above-described embodiments, a mode in which one diffuser plate 60 is arranged has been described as an example, but the present invention is not limited to this, and a plurality of diffuser plates may be used according to the required degree of diffusion.

10, 10A, 10B Measuring device 12, 12A, 12B, 12C Light emitting element 14 Light emitting device 14A Substrate 16 Light receiving element 18 Light receiving device 20 Control unit 30 Optical system 32 Lens 34 Lens 40 Diaphragm 42 Opening 60 Diffusion plate 62 Holding means 64 Movement means 66 slot 70 unevenness 100 measuring device 200 surface C rotation axis IF irradiation light M optical axis RF reflected light OB object C1, C2, C3 curve T measurement area

Claims (13)

a light emitting unit that emits irradiation light to irradiate an object;
a first lens that changes the degree of divergence of the irradiation light emitted from the light emitting unit;
a diaphragm that narrows down the irradiation light emitted from the first lens;
a second lens that collects the irradiation light that has passed through the diaphragm so as to irradiate the object from a predetermined direction;
a light-receiving unit arranged between the aperture unit and the second lens and configured to receive reflected light reflected by the irradiation light applied to the object;
between the second lens and the object, the distance from the object being 1/2 or less of the distance between the second lens and the object, and a scattering means for scattering the irradiated light and the reflected light,
The irradiation light is scattered by the scattering means and irradiated onto the object, and the reflected light is scattered by the scattering means and received by the light receiving unit. The measuring device according to claim 1, wherein the scattering means is a diffusion plate. The measurement according to claim 1 or 2 , wherein the scattering means is arranged at a position where the distance from the object is 1/10 or more of the distance between the second lens and the object. Device. a light emitting unit that emits irradiation light to irradiate an object;
a first lens that changes the degree of divergence of the irradiation light emitted from the light emitting unit;
a diaphragm that narrows down the irradiation light emitted from the first lens;
a second lens that collects the irradiation light that has passed through the diaphragm so as to irradiate the object from a predetermined direction;
a light-receiving unit arranged between the aperture unit and the second lens and configured to receive reflected light reflected by the irradiation light applied to the object;
a scattering means formed on the object-side surface of the second lens for scattering the irradiation light and the reflected light;
The irradiation light is scattered by the scattering means and irradiated to the object, and the reflected light is scattered by the scattering means and received by the light receiving section.
measuring device. The measuring device according to claim 4 , wherein the scattering means is formed integrally with the second lens. 6. The measuring apparatus according to any one of claims 1 to 5 , further comprising holding means capable of holding the scattering means at a plurality of different positions in the optical axis direction of the second lens. 7. The measuring apparatus according to claim 1 , further comprising moving means for moving said scattering means along the optical axis direction of said second lens. The measurement according to any one of claims 1 to 3 , claim 6 , and claim 7 , further comprising removing means for removing said scattering means from between said second lens and said object. Device. The measuring device according to any one of claims 1 to 8 , wherein the distance between the light receiving surface of the light receiving unit and the second lens is equal to the focal length of the second lens. The measuring device according to claim 9 , wherein the distance between the first lens and the diaphragm is equal to the focal length of the first lens. a light emitting unit that emits irradiation light to irradiate an object; a first lens that changes the degree of divergence of the irradiation light emitted from the light emitting unit; a diaphragm that narrows down the irradiation light emitted from the first lens; a second lens for condensing the irradiation light that has passed through the diaphragm so as to irradiate the object from a predetermined direction; a light-receiving unit that receives reflected light reflected by the object irradiated with light, and a scattering means that is disposed between the second lens and the object and scatters the irradiated light and the reflected light; A measuring method using a measuring device comprising
The irradiation light is scattered by the scattering means and irradiated to the object, the reflected light is scattered by the scattering means and received by the light receiving unit, the surface state of the object is measured, and the object is irradiated with the light. measuring method for measuring the surface state of the object by changing the scattering means according to the providing a plurality of the measurement devices each including the different scattering means;
The measuring method according to claim 11 , wherein one of the plurality of measuring devices is selected and measured according to the object. 13. The measuring method according to claim 12 , wherein one of the plurality of measuring devices does not include the scattering means.

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