JP7797931B2 - Light receiving device and measuring device - Google Patents

Description

This disclosure relates to a light receiving device and a measurement device.

Patent Document 1 below discloses a portable colorimeter in which a measurement unit having a light source and a light-receiving unit, a control unit that controls the measurement unit, a display unit that displays the results measured by the measurement unit, and an operation unit that performs color measurement operations are incorporated into a handheld main body that is small and shaped to be held in one hand, the measurement unit being disposed within a window provided in part of the colorimeter main body, the light source being a white LED, and the light-receiving elements of the light-receiving unit being light-receiving sensors for the three primary colors (B, G, R).

Japanese Patent Application Laid-Open No. 2005-257374

For example, if a light source is mounted on a board to which a box with a light-receiving unit is attached, there is a concern that the box may obstruct the light emitted from the light source.

The purpose of this disclosure is to provide a light-receiving device and a measuring device that minimize the obstruction of light emitted from a light source by a box, compared to when a light source is mounted on a board to which a box with a light-receiving unit is attached.

The light-receiving device according to the first aspect comprises a substrate having a first opening formed therein and a light source surrounding the first opening that irradiates light onto an object; a box having a second opening formed therein and a light-receiving unit inside that receives light reflected from the object through the second opening; another substrate attached to the side of the box opposite the second opening; and a fixing unit that fixes the substrate and the other substrate in a position in which at least a portion of the box is inserted into the first opening or in which the reflected light directed toward the second opening passes through the first opening.

The light-receiving device according to the second aspect is the light-receiving device according to the first aspect, wherein the substrate and the other substrate are fixed by the fixing portion when the box is inserted into the first opening, and the gap between the first opening and the side surface of the box is set within the allowable range of positional misalignment between the light-receiving unit and the light source.

The light-receiving device according to the third aspect is the light-receiving device according to the first or second aspect, in which the fixing portions of different lengths can be attached between the substrate and the other substrate.

The light-receiving device according to the fourth aspect is the light-receiving device according to any one of the first to third aspects, further comprising a cover portion provided on the opposite side of the substrate from the other substrate at a distance, the cover portion including a third opening aligned with the positions of the second and first openings, and configured so that light emitted from the light source and passing through the third opening is irradiated onto an object.

The light-receiving device according to the fifth aspect is the light-receiving device according to the fourth aspect, wherein the inner diameter of the third opening is set to be equal to or greater than the distance between the cover portion and the substrate.

The light-receiving device according to the sixth aspect is the light-receiving device according to the fourth or fifth aspect, further comprising another fixing portion that fixes the cover portion and the substrate.

The measuring device according to the seventh aspect comprises a light-receiving device according to any one of the first to sixth aspects, a power source, a display unit that displays a measurement value, and a housing in which the light-receiving device, the power source, and the display unit are arranged, and in the housing, the substrate, the other substrate, the power source, and the display unit are arranged on a straight line that intersects with the surface of the substrate.

The measuring device according to the eighth aspect is the measuring device according to the seventh aspect, wherein an opening for inserting and removing the power supply is formed in the grip portion of the housing.

The measuring device according to the ninth aspect is the measuring device according to the eighth aspect, wherein the gripping portion is provided with an operating portion for performing measurements.

The measuring device according to a tenth aspect is the measuring device according to any one of the seventh to ninth aspects, further comprising a cover portion provided on the opposite side of the substrate from the other substrate at a distance, the cover portion having a third opening aligned with the second opening and the first opening, and the housing is configured to be self-supporting with at least a portion of the cover portion in contact with the object.

The light-receiving device according to the first aspect can prevent the box from interfering with the light emitted from the light source, compared to when the light source is provided on a board to which a box equipped with a light-receiving unit is attached.

The light-receiving device according to the second aspect makes it easier to position the substrate relative to another substrate compared to when the gap between the first opening and the side of the box is larger than the allowable range for misalignment between the light-receiving unit and the light source.

With the light-receiving device according to the third aspect, the amount of reflected light incident on the substrate and the light-receiving unit can be adjusted, compared to when the distance between the substrate and another substrate is fixed at a constant value.

The light-receiving device according to the fourth aspect allows the light source to be brought closer to the object compared to when most of the light emitted from the light source is directly irradiated onto the object.

With the light-receiving device according to the fifth aspect, changes in the measurement value are suppressed when the distance between the object and the cover changes, compared to when the inner diameter of the third opening is smaller than the distance between the cover and the substrate.

With the light-receiving device according to the sixth aspect, it is easier to adjust the distance between the cover and the substrate compared to when the cover is fixed to a component of the light-receiving device other than the substrate.

The measuring device according to the seventh aspect is easier to operate with one hand when it is handy, compared to when the light receiving device, power supply, and display unit are arranged in a zigzag pattern.

The measuring device according to the eighth aspect can prevent the power supply from becoming detached from the housing during use, compared to when an opening for inserting and removing the power supply is formed somewhere other than the grip portion of the housing.

The measuring device according to the ninth aspect is easier to operate with one hand when it is handheld, compared to when the operating unit is located somewhere other than the grip.

With the measuring device according to the tenth aspect, the light receiving section of the box body is less likely to shift relative to the object when measuring the object, compared to when the housing cannot stand on its own with the cover in contact with the object.

FIG. 1 is a perspective view showing an example of a measurement device including a light receiving device according to a first embodiment; 1 is a vertical cross-sectional view showing a measurement device including a light receiving device according to a first embodiment. FIG. 2 is a cross-sectional view showing a part of the light receiving device according to the first embodiment. FIG. 2 is a perspective view showing the light source side of a first substrate used in the light receiving device according to the first embodiment. FIG. 2 is a perspective view showing the box body side of a second substrate used in the light receiving device according to the first embodiment. FIG. 2 is a perspective view showing a state in which a first substrate and a second substrate of the light receiving device according to the first embodiment are arranged. FIG. 2 is a side view showing the state in which the cover, the first board, the second board, and the third board of the light receiving device according to the first embodiment are assembled. FIG. 2 is a side view showing a spacer that fixes the first substrate and the second substrate of the light receiving device according to the first embodiment. FIG. 4 is a side view showing a state in which a spacer is fixed to a second substrate of the light receiving device according to the first embodiment. 10 is a side view showing a state in which a spacer of a first substrate is fixed to a spacer of a second substrate of the light receiving device according to the first embodiment. FIG. FIG. 2 is a bottom view showing the cover, the first substrate, and the second substrate of the light receiving device according to the first embodiment in an exploded state. FIG. 4 is a bottom view showing a state in which the cover of the light receiving device according to the first embodiment is attached to the first board and the second board. FIG. 2 is a cross-sectional view showing a state in which the light receiving device according to the first embodiment is measuring an object. 4 is a schematic diagram illustrating the positional relationship between the light source, the third opening of the cover, and the box in the light-receiving device according to the first embodiment. FIG. FIG. 2 is a schematic diagram illustrating the configuration of the light receiving device according to the first embodiment, showing a state in which the target object and the cover are close to each other. FIG. 2 is a schematic diagram illustrating the configuration of the light receiving device according to the first embodiment, showing a state in which the target object and the cover are far from each other. FIG. 10 is a schematic configuration diagram illustrating a part of a light receiving device according to a second comparative example, showing a third opening of a cover. FIG. 10 is a schematic configuration diagram illustrating a part of a light receiving device according to a second embodiment, showing a third opening of a cover. FIG. 11 is a schematic configuration diagram illustrating a part of a light receiving device according to a third embodiment, showing a third opening of a cover. 10 is a graph showing a first example of the relationship between the thickness of a shim interposed between a cover and an object and the amount of change in color difference. 10 is a graph showing a second example of the relationship between the thickness of a shim interposed between a cover and an object and the amount of change in color difference. FIG. 2 is a perspective view showing a state in which the battery is removed from the housing of the measuring device. FIG. 10 is a cross-sectional view showing a part of a light receiving device according to a fifth embodiment. FIG. 13 is a cross-sectional view showing a part of a light receiving device according to a sixth embodiment. FIG. 13 is a cross-sectional view showing a part of a light receiving device according to a seventh embodiment. FIG. 10 is a schematic diagram illustrating a state in which the target object and the cover are close to each other in the light receiving device of the first comparative example. FIG. 10 is a schematic diagram illustrating the configuration of the light receiving device of the second comparative example in a state where the target object and the cover are far apart.

Embodiments of the present disclosure will be described in detail with reference to the drawings. In each drawing, elements that are less relevant to the technology of the present disclosure have been omitted.

[First embodiment]
A measurement device including a light receiving device according to the first embodiment will be described.

<Overall configuration of the measuring device>
FIG. 1 is a perspective view showing an example of a measuring device 100 including a light-receiving device 10 according to the first embodiment, and FIG. 2 is a cross-sectional view showing the example of the measuring device 100. As shown in FIGS. 1 and 2 , the measuring device 100 includes a housing 102, a battery 104 inserted inside the housing 102, a display device 106 disposed on one side of the housing 102, and a light-receiving device 10 disposed on the other side of the housing 102. In the first embodiment, the measuring device 100 is a device that measures the color difference of an object 150 ( FIG. 3 ) using the light-receiving device 10. Note that the up-down direction in FIGS. 1 and 2 is the Z direction (vertical direction), the left-right direction is the X direction (horizontal direction), and the direction perpendicular to the Z direction and the X direction is the Y direction (horizontal direction). In other drawings, one or more of the X direction, Y direction, and Z direction may be indicated in accordance with FIGS. 1 and 2 .

(Housing)
As shown in FIGS. 1 and 2 , the housing 102 includes a grip portion 112 in the longitudinal middle portion. The grip portion 112 is formed of a rectangular member in a plan view (as viewed from the Z direction) and extends in the longitudinal direction (the Z direction in this embodiment). The grip portion 112 can be held by a user's hand. One surface 112A of the grip portion 112 is formed with an opening 114 for inserting and removing the battery 104 (see FIG. 1 ). The opening 114 of the measuring device 100 may be fitted with an openable or removable cover. The battery 104 is an example of a power source. The opening 114 is, for example, rectangular and extends along the longitudinal direction of the grip portion 112. The battery 104 is, for example, rectangular. The battery 104 can be removed from the housing 102 through the opening 114 of the grip portion 112 (see FIG. 18 ).

The grip portion 112 is provided with an operation unit 116 for performing measurements. As an example, the operation unit 116 is a push button, and measurements are performed by pressing the operation unit 116. As an example, the operation unit 116 is provided on one surface 112A of the grip portion 112, on the side closer to the display device 106 in the longitudinal direction of another surface constituting the grip portion 112 that is adjacent to the other surface. By providing the operation unit 116 in this position, when a user grips the grip portion 112 to operate the operation unit 116, the user's fingers or palm will cover the opening 114. This prevents the battery 104 from falling out of the opening 114 while the user is using the measuring device 100. Here, when a user grips the grip portion 112 to operate the operation unit 116, it means that the user positions the tip of one finger (such as the thumb) on the operation unit 116.

(Display device)
The display device 106 is disposed on one side of the housing 102 in the longitudinal direction (in the Z direction in this embodiment) of the grip portion 112. The width of the display device 106 is larger than the width of the grip portion 112 (width in the X direction and Y direction). The display device 106 includes a display unit 122 and an input unit 124 (see FIG. 1). The display unit 122 is provided on the end surface 106A of the display device 106 opposite the grip portion 112. The display unit 122 is configured, for example, with a liquid crystal screen. The display unit 122 displays, for example, measured values and the like.

(Light receiving device)
The light receiving device 10 is disposed on the other side of the housing 102 in the longitudinal direction (Z direction in this embodiment) of the grip portion 112, opposite the display device 106. A cover 26, which will be described later, is provided on the end of the light receiving device 10 opposite the grip portion 112 (see FIG. 2). The measuring device 100 is configured so that the housing 102 can stand on its own with a portion of the cover 26 placed on an installation surface. As a result, the measuring device 100 is configured so that the housing 102 can stand on its own with a portion of the cover 26 in contact with an object 150 (see FIG. 3), which is the measurement target. The configuration of the light receiving device 10 will be described later.

(Relationships between components of the measuring device)
2 , in the housing 102, the first substrate 12, second substrate 18, battery 104, and display unit 122 of the display device 106, which will be described later, of the light receiving device 10 are arranged on a straight line extending in a direction intersecting with the plate surface of the first substrate 12. In the first embodiment, the centers of gravity of the light receiving device 10, the battery 104, and the display device 106 are arranged on a straight line extending in a direction intersecting with the plate surface of the first substrate 12.

As an example, in the measuring device 100, the display device 106 and the light-receiving device 10 are electrically connected by a cable 130 and a connector 132. The battery 104 and the light-receiving device 10 are electrically connected by a cable 134 and a connector 132. The operation unit 116 and the light-receiving device 10 are electrically connected by a cable 136. In the measuring device 100, the light-receiving device 10 is operated by operating the operation unit 116, and the measurement value of the object 150 taken by the light-receiving device 10 is displayed on the display unit 122 of the display device 106.

<Overall configuration of the light receiving device>
Next, a description will be given of the light receiving device 10 according to the first embodiment. Fig. 3 is a cross-sectional view showing a part of the light receiving device 10. In Fig. 3, the cover 26 is omitted.

As shown in Figure 3, the light receiving device 10 has a first substrate 12 as an example of a substrate, a box 16 with a light receiving unit 14 inside, and a second substrate 18 as an example of another substrate to which the box 16 is attached (see Figure 2). The light receiving device 10 also has a spacer 20 that secures the first substrate 12 and the second substrate 18 together.

The light receiving device 10 also includes a third substrate 24 located opposite the second substrate 18 and on the opposite side of the second substrate 18 from the first substrate 12, and a spacer 22 that secures the third substrate 24 to the second substrate 18.

As shown in FIG. 2, the light receiving device 10 also includes a cover 26 that is spaced apart from the first substrate 12 on the opposite side of the second substrate 18. The cover 26 is an example of a covering portion.

(First substrate)
3 and 4 , a first opening 30 is formed in the first substrate 12. The first substrate 12 has a light source 32 around the first opening 30 that irradiates light onto the object 150. The light source 32 is provided on one surface 12A of the first substrate 12 in the Z direction (the bottom surface located on the opposite side to the second substrate 18). Note that, in the first substrate 12, components that are less relevant to the technology of the present disclosure are not shown in the drawings.

As an example, the first substrate 12 is rectangular in plan view (when viewed from the Z direction). Also, as an example, the first opening 30 is rectangular in plan view (when viewed from the Z direction), and four light sources 32 are provided on the outside of the four sides of the first opening 30 (see Figure 4). For example, a white LED or the like is used as the light source 32.

The first substrate 12 has a plurality of through holes 34 (four in this embodiment) at its edge (four corners in this embodiment) through which bolts pass. A spacer 20 is disposed at each of the through holes 34. The through holes 34 are circular, and the inner diameter is smaller than the outer diameter of the spacer 20. A bolt can be inserted into the through hole 34 to be fastened to the screw hole 20C of the spacer 20. The configuration of the spacer 20 and other components will be described later.

On the surface opposite to the surface 12A of the first board 12 on which the light source 32 is provided, there is provided a pin socket 36 with an insertion portion to which a pin header 46 (see Figure 5) from the second board 18 is connected.

(Box body and light receiving part)
3 and 5, the box 16 is attached to one surface 18A in the Z direction (the lower surface on the first substrate 12 side) of the second substrate 18. The box 16 is rectangular in plan view (as viewed from the Z direction), and a second opening 40 is formed in the bottom surface 16A of the box 16 on the first substrate 12 side. The box 16 has an internal light receiving unit 14 that receives light that has entered through the second opening 40 and is reflected from an object 150.

In a plan view (when viewed from the Z direction), the outer shape of the box body 16 is smaller than the first opening 30 of the first substrate 12. In other words, the length of the box body 16 in the X direction is shorter than the length of the first opening 30 in the X direction, and the length of the box body 16 in the Y direction is shorter than the length of the first opening 30 in the Y direction. As an example, at least a portion of the box body 16 (near the bottom surface 16A in the first embodiment) is inserted into the first opening 30 (see Figure 3).

In the first embodiment, the box 16 constitutes a spectroscope. A spectroscopic element 42 provided on the second substrate 18 is disposed inside the box 16 (inside). The spectroscopic element 42 is disposed opposite the second opening 40, and receives incident light (reflected light) that enters the box 16 from the object 150 through the second opening 40. A grating chip such as a reflective concave blazed grating is used as the spectroscopic element 42, for example.

The second opening 40 is, for example, circular. In the first embodiment, the second opening 40 is composed of an inclined surface whose inner diameter gradually decreases from the bottom surface 16A of the box body 16, a wall surface extending radially inward from the inclined surface, and an opening provided in the wall surface (i.e., an opening whose inner diameter is smaller than that of the inclined surface). The shape of the second opening 40 can be changed. The second opening 40 may also be composed only of an inclined surface whose inner diameter gradually decreases from the bottom surface 16A of the box body 16.

The light receiving unit 14 is positioned opposite a portion of the spectroscopic element 42 and receives light dispersed by the spectroscopic element 42. In the first embodiment, the light receiving unit 14 is provided on the inside of the bottom surface 16A of the box body 16. For example, a CMOS linear image sensor is used as the light receiving unit 14.

As shown in Figures 3 and 6, with a portion of the box body 16 inserted into the first opening 30 of the first substrate 12, the first substrate 12 and the second substrate 18 are fixed together with spacers 20 and 22 (see Figure 3). In this state, the gap between the first opening 30 and the side surface 16B of the box body 16 (the gap in the direction intersecting the Z direction) is set within the tolerance range for misalignment between the light receiving unit 14 and the light source 32. In other words, the gap between the length between the pair of side surfaces 16B of the box body 16 facing the X direction and the length of the first opening 30 in the X direction, and the gap between the length between the pair of side surfaces 16B of the box body 16 facing the Y direction and the length of the first opening 30 in the Y direction are set within the tolerance range for misalignment between the light receiving unit 14 and the light source 32.

(Second substrate)
As shown in FIGS. 3 and 5 , the side of the box 16 opposite the second opening 40 is attached to the surface 18A of the second substrate 18. In the first embodiment, the box 16 is open on the side opposite the bottom surface 16A, and the end surface of the upper end 16C of the box 16 is attached to the surface 18A of the second substrate 18. As an example, the second substrate 18 is rectangular in plan view (as viewed from the Z direction). Furthermore, a pin header 46 for connecting to the first substrate 12 is provided on the surface 18A of the second substrate 18. The pin header 46 of the second substrate 18 is inserted into the pin socket 36 of the first substrate 12, thereby electrically connecting the first substrate 12 and the second substrate 18. Note that components of the second substrate 18 that are not particularly relevant to the technology of the present disclosure are not shown in the drawings.

The second substrate 18 has a plurality of (four in this embodiment) through-holes 34 at its edge (four corners in this embodiment) through which bolts pass. A spacer 20 is placed in each through-hole 34. The through-holes 34 are circular, and the inner diameter is smaller than the outer diameter of the spacer 20. The bolt portion 20B extending from the main body portion 20A of the spacer 20 can be inserted into the through-hole 34 (Figure 3).

(spacer)
As shown in FIGS. 7 and 8 , the light-receiving device 10 includes a spacer 20 that secures the first substrate 12 and the second substrate 18 together, a spacer 22 that secures the second substrate 18 and the third substrate 24 together, and a spacer 50 that secures the first substrate 12 and the cover 26 together. For example, four spacers 20, 22, and 50 are provided. The spacers 20, 22, and 50 are equal in length, but may be of different lengths. Furthermore, a counterbore is formed on the end surface 26A of the cover 26. The counterbore prevents the heads of the bolts 52 that fasten the cover 26 to the spacers 50 from protruding from the end surface 26A (see FIG. 12 ). The counterbore is located at a position corresponding to the through-hole 62 in the cover 26. A nut 54 that secures the spacer 22 is provided on the upper side of the third substrate 24 in the Z direction. The spacers 20 and 22 are examples of fixing parts. The spacer 50 and the bolt 52 are an example of another fixing portion.

The spacer 20 comprises a main body 20A, a bolt portion 20B extending axially from one axial end of the main body 20A, and a threaded hole 20C provided at the other axial end of the main body 20A. The main body 20A is, for example, cylindrical. Similarly, the spacer 22 comprises a main body 22A, a bolt portion 22B, and a threaded hole 22C. The bolt portion 20B of the spacer 20 passes through the through hole 34 of the second substrate 18 and can be fastened to the threaded hole 22C of the spacer 22. Similarly, the spacer 50 comprises a main body 50A, a bolt portion 50B, and a threaded hole 50C. The bolt portion 50B of the spacer 50 passes through the through hole 34 of the first substrate 12 and can be fastened to the threaded hole 20C of the spacer 20.

The second board 18 and the third board 24 are electrically connected by inserting a pin header (not shown) into a pin socket 56. The third board 24 is provided with mounted components 58 including a control unit for driving each part of the light receiving device 10.

As an example, when assembling the light receiving device 10, as shown in FIG. 9A, the bolt portion 20B of the spacer 20 is inserted through the through-hole 34 of the second substrate 18, and the spacer 22 is rotated to temporarily fasten the bolt portion 20B of the spacer 20 to the screw hole 22C of the spacer 22. This temporarily fastens four spacers 20 to the side of the second substrate 18 facing the box 16, and temporarily fastens four spacers 22 to the side of the second substrate 18 opposite the box 16.

Then, as shown in Figure 9B, the first substrate 12 is placed on the spacer 20 side, and the bolt portion 22B of the spacer 22 is inserted into the through-hole 34 of the third substrate 24. In this state, the spacer 22 and spacer 20 are rotated in opposite directions to fully tighten the spacer 22 and spacer 20. By repeating this process, the first substrate 12, second substrate 18, and third substrate 24 of the light receiving device 10 are assembled.

Although not shown in the figure, a spacer serving as an example of a fixing part having a length different from that of the spacer 20 can be attached between the first substrate 12 and the second substrate 18 in place of the spacer 20.

(cover)
7 and 10 to 12, the cover 26 has a third opening 60 that is aligned with the first opening 30 of the first substrate 12 and the second opening 40 of the box body 16. The light receiving device 10 is configured such that light emitted from the light source 32 of the first substrate 12 and passing through the third opening 60 is irradiated onto the object 150 (see FIG. 12).

As an example, the cover 26 is rectangular in plan view (when viewed from the Z direction). Through holes 62, through which the shanks of the bolts 52 pass, are provided at the edges of the cover 26 (at the four corners in the first embodiment). The through holes 62 are, for example, circular.

As described above, the light receiving device 10 includes a spacer 50 that secures the cover 26 to the first substrate 12. The bolt portion 50B of the spacer 50 passes through the through hole 34 of the first substrate 12 and is tightened into the screw hole 20C of the spacer 20. This attaches the spacer 50 to the first substrate 12. Furthermore, a bolt 52 is passed through the through hole 62 of the screw hole 50C of the spacer 50 from the end surface 26A side of the cover 26 and tightened into the screw hole 50C of the spacer 50. This secures the cover 26 to the first substrate 12 with the spacer 50 and bolt 52 (see Figure 12).

The inner surface of the cover 26 is preferably a color that absorbs light (i.e., does not reflect light), such as black. This prevents light from being reflected by the cover 26, and light emitted from the light source 32 and passing through the third opening 60 is irradiated onto the object 150. As an example, the third opening 60 has a circular shape in a plan view (as viewed from the Z direction). For example, the inner diameter of the third opening 60 is set to be equal to or greater than the distance between the cover 26 and the first substrate 12.

(Positional relationship between the light source, cover, and box)
In the light-receiving device 10, in order to exclude specularly reflected light from the light source 32 and obtain diffused light, it is preferable that light emitted from all of the multiple light sources 32 be incident on the object 150 at an angle of at least 45 to 60 degrees (angle with respect to the Z direction). For this reason, it is preferable that the positions of the light source 32, the cover 26, and the box 16 are set so that the center of the light spot diameter is located within the range in which the object 150 is irradiated by light at the above angle.

If the third opening 60 of the cover 26 is too wide, reflected light from outside (i.e., light other than from the light source 32) will be more likely to enter the interior of the box 16 through the second opening 40 of the box 16. For this reason, the inner diameter of the third opening 60 of the cover 26 must be set so that the light emitted from all of the multiple light sources 32 strikes the target object 150 at an angle of at least 45 to 60 degrees.

Figure 13 is a schematic diagram showing the positional relationship between the light source 32, the box 16, and the third opening 60 of the cover 26. As shown in Figure 13, in order to set the light emitted from all of the multiple light sources 32 to strike the object 150 at an angle θ of at least 45 to 60° (angle θ relative to the Z direction), the inner diameter D1 of the third opening 60 must be, for example, approximately φ15 mm. Furthermore, the measurement diameter of the object 150 is defined as MD1, and the distance from one surface (bottom surface) 12A of the first substrate 12 on which the light source 32 is provided to the end surface (bottom surface) 26A of the cover 26 (hereinafter referred to as the "distance between the first substrate 12 and the cover 26") is defined as WD1. For example, if the distance WD1 between the first substrate 12 and the cover 26 is 8.5 mm and the numerical aperture of the box 16 is 0.23, the measurement diameter MD1 is uniquely determined by the distance WD1 between the first substrate 12 and the cover 26, and therefore the measurement diameter MD1 is φ4 mm.

Figure 14A shows an example of measurement in which the object 150 was placed close to the end surface 26A of the cover 26. In Figure 14A, the end surface 26A of the cover 26 and the object 150 are shown separated from each other to make the configuration of each part easier to understand. However, in reality, the end surface 26A of the cover 26 and the object 150 are almost in contact. In Figure 14A, to obtain diffused light, the light source 32 is positioned so that it enters the third opening 60 of the cover 26 at an angle of approximately 45°. That is, the angle θ of the light from the light source 32 entering the third opening 60 of the cover 26 with respect to the Z direction is approximately 45°. Furthermore, the distance WD1 between the first substrate 12 and the cover 26 is 8.5 mm, and the inner diameter D1 of the third opening 60 of the cover 26 is φ15 mm. The inner diameter D1 of the third opening 60 of the cover 26 is set to be equal to or greater than the distance WD1 between the first substrate 12 and the cover 26.

Figure 14B shows an example of measurement in which the object 150 was placed at a position far from the end surface 26A of the cover 26. As shown in Figure 14B, the distance D3 between the end surface 26A of the cover 26 and the object 150 is approximately 1 mm. Therefore, the distance from the light source 32 to the object 150 is the distance WD1 between the first substrate 12 and the cover 26, which is 8.5 mm, plus the distance D3 between the end surface 26A of the cover 26 and the object 150, which is 1 mm. In other words, the distance from the light source 32 to the object 150 is 9.5 mm.

As shown in Figure 14B, when the inner diameter D1 of the third opening 60 of the cover 26 is φ15 mm, the third opening 60 of the cover 26 blocks less of the light from the light source 32, so there is less change in the light that strikes the object 150. As a result, there is less change in the measurement value of the light received by the light receiving unit 14 inside the box 16.

Figures 22A and 22B show an example of measuring an object 150 using a light receiving device 500 of the first comparative example. As shown in Figures 22A and 22B, the light receiving device 500 of the first comparative example has only the cover 502 changed from the light receiving device 10 of the first embodiment. The cover 502 has a third opening 504 aligned with the first opening 30 of the first substrate 12, and the inner diameter D1 of the third opening 504 is φ4 mm. The distance WD1 between the first substrate 12 and the cover 502 is 8.5 mm.

Figure 22A shows an example of measurement in which the object 150 is placed close to the end surface 502A of the cover 502. In Figure 22A, to make the configuration of each part easier to understand, the end surface 502A of the cover 502 and the object 150 are shown as being separated from each other, but in reality, the end surface 502A of the cover 502 and the object 150 are almost in contact with each other.

Figure 22B shows an example of measurement in which the object 150 was placed at a position far from the end surface 502A of the cover 502. As shown in Figure 22B, the distance D3 between the end surface 502A of the cover 502 and the object 150 is approximately 1 mm.

As shown in Figure 22B, when the inner diameter D1 of the third opening 504 of the cover 502 is φ4 mm, the light from the light source 32 is blocked by the third opening 504 of the cover 502, and the amount of light striking the target object 150 is significantly reduced compared to the case shown in Figure 22A. This results in a larger change in the measurement value received by the light receiving unit 14 inside the box 16.

<Action and effect>
Next, the operation and effects of this embodiment will be described.

The light-receiving device 10 includes a first substrate 12 having a first opening 30 formed therein and a light source 32 surrounding the first opening 30 that irradiates light onto the object 150. The light-receiving device 10 also includes a box 16 having a second opening 40 formed therein and a light-receiving unit 14 inside that receives light reflected from the object 150 that enters through the second opening 40. The light-receiving device 10 also includes a second substrate 18 attached to the side of the box 16 opposite the second opening 40. The light-receiving device 10 also includes a spacer 20 and a spacer 22 that secure the first substrate 12 and the second substrate 18 together, with at least a portion of the box 16 inserted into the first opening 30.

In the light-receiving device 10, light emitted from the light source 32, passes through the third opening 60 of the cover 26, hits the object 150, is reflected, and the reflected light enters the box 16 through the second opening 40 of the box 16 and is received by the light-receiving unit 14 provided inside the box 16. In the first embodiment, the light reflected from the object 150 enters the box 16 through the second opening 40 of the box 16, hits the spectroscopic element 42 and is split, and the split light is received by the light-receiving unit 14. In this way, the light-receiving device 10 measures the color difference of the object 150.

As described above, the light receiving device 10 includes a first substrate 12 having a light source 32 around the first opening 30, and a second substrate 18 attached to the side of the box 16 opposite the second opening 40.

As a result, in the light receiving device 10, the box 16 is less likely to obstruct the light emitted from the light source 32 than when the light source 32 is provided on the second substrate 18 to which the box 16 equipped with the light receiving unit 14 is attached. In other words, when the light source 32 is positioned while maintaining the angle of incidence of the light emitted from the light source 32, the light receiving device 10 becomes more compact in the surface direction of the first substrate 12.

In addition, in the light-receiving device 10, the first substrate 12 and the second substrate 18 are fixed with spacers 20 and 22 when the box body 16 is inserted into the first opening 30, and the gap between the first opening 30 and the side surface 16B of the box body 16 is set within the allowable range for misalignment between the light-receiving unit 14 and the light source 32.

As a result, in the light-receiving device 10, it is easier to position the first substrate 12 and the second substrate 18 compared to when the gap between the first opening 30 and the side surface 16B of the box body 16 is larger than the allowable range for misalignment between the light-receiving unit 14 and the light source 32.

In addition, the light receiving device 10 allows spacers 20 of different lengths to be attached between the first substrate 12 and the second substrate 18.

As a result, in the light receiving device 10, the amount of reflected light incident on the first substrate 12 and the light receiving unit 14 can be adjusted, compared to when the first substrate 12 and the second substrate 18 are fixed at a constant distance.

The light-receiving device 10 also includes a cover 26 that is spaced apart from the first substrate 12 on the opposite side from the second substrate 18, and the cover 26 includes a third opening 60 that is aligned with the positions of the second opening 40 and the first opening 30. The light-receiving device 10 is configured so that light emitted from the light source 32 and passing through the third opening 60 is irradiated onto the object 150. Simply bringing the light source 32 closer to the object 150 can cause robustness issues (i.e., issues such as the influence of light incident from outside the light-receiving device 10). However, by irradiating the object 150 with light emitted from the light source 32 and passing through the third opening 60 of the cover 26, robustness can be improved (i.e., the influence of light incident from outside the light-receiving device 10 can be reduced).

For this reason, in the light receiving device 10, the light source 32 can be brought closer to the object 150 compared to when most of the light emitted from the light source 32 is directly irradiated onto the object 150.

Furthermore, in the light receiving device 10, the inner diameter D1 of the third opening 60 is set to be equal to or greater than the distance between the cover 26 and the first substrate 12, i.e., the distance WD1 between the cover 26 and the first substrate 12. This makes it less likely that the light irradiated onto the object 150 will decrease when the distance between the object 150 and the cover 26 changes.

As a result, in the light receiving device 10, changes in the measurement value are suppressed when the distance between the object 150 and the cover 26 changes, compared to when the inner diameter D1 of the third opening 60 is smaller than the distance between the cover 26 and the first substrate 12.

The light receiving device 10 also has a spacer 50 and a bolt 52 that secure the cover 26 and the first substrate 12.

For this reason, in the light receiving device 10, it is easier to adjust the distance between the cover 26 and the first substrate 12 compared to when the cover 26 is fixed to a component of the light receiving device 10 other than the first substrate 12.

The measuring device 100 also includes a light receiving device 10, a battery 104, a display unit 122 that displays the measured value, and a housing 102 in which the light receiving device 10, battery 104, and display unit 122 are arranged. In the housing 102, the first board 12, second board 18, battery 104, and display unit 122 are arranged on a straight line that intersects with the surface of the first board 12.

For this reason, the measuring device 100 is easier to operate with one hand when it is handheld, compared to when the light receiving device 10, battery 104, and display unit 122 are arranged in a zigzag pattern.

In addition, the measuring device 100 has an opening 114 formed in the grip portion 112 of the housing 102 for inserting and removing the battery 104. As a result, when using the measuring device 100, the opening 114 of the grip portion 112 is often gripped by the user's fingers or the like, causing part of the opening 114 to become blocked.

As a result, the measuring device 100 can prevent the battery 104 from coming off the housing 102 during use, compared to when an opening 114 for inserting and removing the battery 104 is formed in the housing 102 other than the grip portion 112.

In addition, the measuring device 100 has an operating unit 116 on the gripping unit 112 for performing measurements.

For this reason, the measuring device 100 is easier to operate with one hand when it is handheld, compared to when the operating unit 116 is located somewhere other than the grip unit 112.

The measuring device 100 also includes a cover 26 that is spaced apart from the first substrate 12 on the opposite side of the second substrate 18. The cover 26 includes a third opening 60 that is aligned with the positions of the second opening 40 and the first opening 30. The measuring device 100 is configured so that the housing 102 can stand on its own with at least a portion of the cover 26 in contact with the object 150.

For this reason, in the measuring device 100, the light receiving unit 14 of the box body 16 is less likely to shift relative to the object 150 when measuring the object 150, compared to when the housing 102 cannot stand on its own with the cover 26 in contact with the object 150.

[Experiment measuring the third opening of the cover after changing it]
Next, experiments were conducted to investigate the relationship between the measurement value of the light receiving device and the distance between the cover and the target object for multiple light receiving devices in which the size and shape of the third opening of the cover were changed. Note that in each light receiving device, the same components as those in the first embodiment described above are assigned the same numbers and their description will be omitted.

Figure 15A is a schematic diagram showing a light receiving device 520 of a second comparative example. As shown in Figure 15A, in the light receiving device 520 of the second comparative example, the third opening 524 of the cover 522 is tapered, with the inner diameter gradually decreasing toward the end surface 522A of the cover 522. The inner diameter D1 of the smallest portion of the third opening 524 of the cover 522 is φ4 mm, and the inner diameter D2 of the largest portion of the tapered surface of the third opening 524 of the cover 522 is 14.4 mm. The angle θ2 of the tapered surface of the third opening 524 with respect to the horizontal is 60°. The thickness t of the housing 526 including the cover 522 is 3 mm, and the distance WD1 between the first substrate 12 and the cover 522 is 8.88 mm. The rest of the configuration is similar to that of the light receiving device 10 of the first embodiment.

Figure 15B is a schematic diagram showing the configuration of the light receiving device 200 of the second embodiment. As shown in Figure 15B, in the light receiving device 200 of the second embodiment, a protrusion 206 that protrudes from the cover 202 toward the opposite side of the box 16 is provided on the edge of the third opening 204 of the cover 202. The inner diameter D1 of the third opening 204 of the cover 202 is φ10 mm. The outer diameter D5 of the protrusion 206 is 12 mm. The thickness t of the cover 202 is 1.5 mm. The rest of the configuration is the same as the configuration of the light receiving device 10 of the first embodiment.

Figure 15C is a schematic diagram showing the configuration of a light receiving device 220 of the third embodiment. As shown in Figure 15C, the light receiving device 220 of the third embodiment has a circular step 226 provided on the inside edge of the third opening 224 of the cover 222 (i.e., on the box 16 side). The inner diameter D1 of the third opening 224 of the cover 222 is φ15 mm. The inner diameter D6 of the step 226 is 40 mm. The height h of the step 226 is 1.5 mm. The rest of the configuration is the same as that of the light receiving device 10 of the first embodiment.

Although not shown in the figures, the light receiving device of the fourth embodiment has the same configuration as the light receiving device 220 of the third embodiment, except that the inner diameter D1 of the third opening 224 of the cover 222 is changed to φ10 mm.

In the experiment, the light receiving device 10 of the first embodiment, the light receiving device 200 of the second embodiment, the light receiving device 220 of the third embodiment, the light receiving device of the fourth embodiment, and the light receiving device 520 of the second comparative example were used to measure the object while changing the distance between the cover and the object. The distance between the cover and the object was changed by changing the thickness of the shim placed between the cover and the object.

Figure 16 is a graph showing the relationship between the thickness of the shim and the amount of change in color difference ΔE measured by the light-receiving device in the first experiment. The thickness of the shim corresponds to the distance between the cover and the target object. In addition, in the first experiment, all light sources 32 of the light-receiving device 10 of the first embodiment were set so that the angle θ (angle with respect to the Z direction) between the center of the light spot from the light source 32 and the center of the light source 32 (center of the LED) was between 45° and 60°.

As shown in Figure 16, it was confirmed that the light receiving device 10 of the first embodiment, the light receiving device 220 of the third embodiment, and the light receiving device of the fourth embodiment showed a significantly small change in color difference ΔE even when the distance between the cover and the object changed. With the light receiving device 200 of the second embodiment, it was confirmed that the change in color difference ΔE increased as the distance between the cover and the object increased, but the change in color difference ΔE was smaller than with the light receiving device 520 of the second comparative example.

Figure 17 is a graph showing the relationship between the change in color difference ΔE measured by the light receiving device and the thickness of the shim in the second experiment. In the second experiment, for all light sources 32 of the light receiving device 10 of the first embodiment, the distance WD1 between the first substrate 12 and the cover 26 was set to 8.5 mm so that the light spot diameter φ4 mm was smaller than the irradiation width of the target object.

As shown in Figure 17, it was confirmed that the light receiving device 10 of the first embodiment, the light receiving device 220 of the third embodiment, and the light receiving device of the fourth embodiment showed a significantly small change in color difference ΔE even when the distance between the cover and the object changed. With the light receiving device 200 of the second embodiment, it was confirmed that the change in color difference ΔE increased as the distance between the cover and the object increased, but the change in color difference ΔE was smaller than with the light receiving device 520 of the second comparative example.

〔others〕
The light receiving device and measuring device of the present disclosure are not limited to the configurations of the first to fourth embodiments, and various modifications can be made without departing from the scope of the technology of the present disclosure. Light receiving devices of other embodiments will be described below. Note that the same components as those of the first to fourth embodiments described above will be assigned the same numbers and their description will be omitted.

Figure 19 is a structural diagram showing a portion of a light receiving device 240 of the fifth embodiment. As shown in Figure 19, the light receiving device 240 includes a box body 242 attached to the second substrate 18. The box body 242 is cubic in shape and includes an upper wall 242A attached to the second substrate 18. Inside the box body 242, a spectroscopic element 42 is provided on the inner surface of the upper wall 242A. The rest of the configuration is similar to that of the light receiving device 10 of the first embodiment.

The light receiving device 240 of the fifth embodiment has the same configuration as the light receiving device 10 of the first embodiment, and can therefore achieve the same functions and effects.

Figure 20 is a structural diagram showing a portion of a light receiving device 260 of the sixth embodiment. As shown in Figure 20, the light receiving device 260 includes a box 262 attached to the second substrate 18. The box 262 is cubic in shape, and a second opening 264 is formed in the bottom wall 262A on the first substrate 12 side. The box 262 includes an upper wall 262B attached to the second substrate 18. A light receiving unit 266 is provided on the inner surface of the upper wall 242B inside the box 242, and receives reflected light from an object (not shown) that enters through the second opening 264.

A color filter 268 is provided inside the box 262, between the second opening 264 and the light receiving unit 266. As an example, the color filter 268 is attached to the inside of the bottom wall 262A. As a result, reflected light from an object (not shown) enters the inside of the box 262 through the second opening 264, passes through the color filter 268, and is received by the light receiving unit 266. The rest of the configuration is the same as that of the light receiving device 10 of the first embodiment.

The light receiving device 260 of the sixth embodiment has the same configuration as the light receiving device 10 of the first embodiment, and can achieve the same functions and effects.

Figure 21 is a structural diagram showing a portion of a light receiving device 280 of the seventh embodiment. As shown in Figure 21, the light receiving device 280 has a box body 282 attached to the second substrate 18. The box body 282 does not have an upper wall facing the bottom wall 262A, and the end face of the upper end portion 282B of the box body 282 is attached to the second substrate 18. A light receiving unit 266 is provided on the second substrate 18 inside the box body 282 to receive reflected light from an object (not shown) that enters through the second opening 264. The rest of the configuration of the light receiving device 280 is similar to the configuration of the light receiving device 260 of the sixth embodiment.

The light receiving device 280 of the seventh embodiment has the same configuration as the light receiving device 10 of the first embodiment, and can therefore achieve the same functions and effects.

In the first to seventh embodiments, at least a portion of the box body is inserted into the first opening 30 of the first substrate 12, but the present disclosure is not limited to this configuration. Although not shown, for example, a configuration may be adopted in which the box body is not inserted into the first opening 30 of the first substrate 12, and the first substrate 12 and the second substrate 18 are fixed by a fixing portion in a position in which reflected light from an object heading toward the second opening 40 passes through the first opening 30.

While the present invention has been described in detail with reference to a specific embodiment, it will be apparent to those skilled in the art that the present invention is not limited to such an embodiment, and that various other embodiments are possible within the scope of the present invention.

10 Light receiving device 12 First substrate (an example of a substrate)
12A: One surface 14: Light receiving unit 16: Box body 16A: Bottom surface 16B: Side surface 18: Second substrate (an example of another substrate)
18A One side 20 Spacer (an example of a fixing part)
22 Spacer (an example of a fixing portion)
26 Cover (an example of a covering portion)
26A End surface 30 First opening 32 Light source 40 Second opening 50 Spacer (an example of another fixing portion)
52 Volt 60 Third opening 100 Measuring device 102 Housing 104 Battery (an example of a power source)
112 Grip portion 112A One surface 114 Opening 116 Operation portion 122 Grip portion 122 Display portion 150 Target object 200 Light receiving device 202 Cover (an example of a cover portion)
204 Third opening 220 Light receiving device 222 Cover (an example of a covering portion)
224 Third opening 230 Light receiving device 232 Cover (an example of a covering portion)
234 Third opening 240 Light receiving device 242 Box 260 Light receiving device 262 Box 264 Third opening 266 Light receiving section 280 Light receiving device 282 Box 282B Upper end D1 Inner diameter (inner diameter of third opening)

Claims (10)

a plate-shaped substrate having a first opening formed therein and a light source disposed around the first opening for irradiating light onto an object;
a box having a second opening formed therein , the box having a spectroscopic element that receives light that has entered through the second opening and is reflected from the object, and a light receiving unit that is disposed on the surface on which the second opening is formed and receives the light that has been spectroscopically separated by the spectroscopic element ;
another plate-shaped substrate attached to the box body on the side opposite to the second opening;
a fixing portion that fixes an edge portion of the substrate and an edge portion of the other substrate in a position where at least a portion of the box body is inserted into the first opening;
A light receiving device comprising: the substrate and the other substrate are fixed by the fixing portion in a state in which the box body is inserted into the first opening,
The light receiving device according to claim 1 , wherein a gap between the first opening and the side surface of the box is set within an allowable range of positional deviation between the light receiving unit and the light source. The light-receiving device described in claim 1 or claim 2, wherein the fixing portions of different lengths can be attached between the substrate and the other substrate. a cover portion provided on the substrate on the opposite side to the other substrate at a distance, the cover portion including a third opening that is positioned to align with the second opening and the first opening;
4. The light receiving device according to claim 1, wherein the light emitted from the light source and passing through the third opening is irradiated onto an object. The light-receiving device described in claim 4, wherein the inner diameter of the third opening is set to be equal to or greater than the distance between the cover portion and the substrate. The light-receiving device described in claim 4 or claim 5, further comprising another fixing portion that fixes the cover portion and the substrate. A light receiving device according to any one of claims 1 to 6;
Power supply and
a display unit that displays the measurement value;
a housing in which the light receiving device, the power supply, and the display unit are disposed,
The measuring device has the substrate, the other substrate, the power supply, and the display unit arranged in a straight line that intersects with the surface of the substrate in the housing. The measuring device described in claim 7, wherein an opening for inserting and removing the power supply is formed in the grip portion of the housing. The measuring device described in claim 8, wherein the gripping portion is provided with an operating portion for performing measurements. a cover portion provided on the opposite side of the substrate from the other substrate at a distance, the cover portion including a third opening disposed in alignment with the second opening and the first opening;
10. The measuring device according to claim 7, wherein the housing is configured to be self-supporting with at least a portion of the cover in contact with the object.