Detection device

Abstract

To provide a detection device capable of obtaining satisfactory detection precision.SOLUTION: A detection device includes: an optical sensor including multiple light detection elements disposed planarly; a light guide plate that is disposed while overlapping with one side in a first direction relative to the optical sensor and has light transmission properties; a light source that is disposed adjacently in a second direction crossing the first direction relative to the light guide plate and applies light to a side face of the light guide plate; and multiple light scattering bodies that are disposed nonoverlappingly with a light detection element when viewed from the first direction between the optical sensor and the light guide plate and scatter light propagated within the light guide plate. The light scattering bodies are one-piece moldings and are provided in a state abutting on the light guide plate.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a detection device.

Background Art

[0002] Detection devices capable of detecting fingerprint patterns and vein patterns are known (for example, Patent Documents 1 and 2). In the detection devices described in Patent Documents 1 and 2, a front light is provided on the front side of a plurality of photodiodes. That is, a front light is provided between a detection object such as a finger and the plurality of photodiodes. However, among the light emitted from the front light, there is a possibility that the contrast of detection may decrease due to the light directly incident on the plurality of photodiodes on the side opposite to the detection object.

[0003] For this reason, a configuration of a front light in which a light source is arranged on the side of a light guide plate is assumed, and a light diffusion structure having a cross-sectional triangular shape that is recessed on the detection object side, for example, is provided on the surface of the light guide plate on the photodiode side. According to this, the light of the light source can be made to enter from the side of the light guide plate, and the light propagating in the light guide plate can be applied to the light diffusion structure having a cross-sectional triangular shape and emitted toward the detection object.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The light incident on the photodiode includes the light incident on the photodiode from the object to be detected through the light guide plate and the light incident on the photodiode that is refracted when the light from the object to be detected hits the light diffusion structure. Thus, since the light incident on the photodiode includes the light refracted when hitting the light diffusion structure, the detection accuracy may decrease.

[0006] An object of the present disclosure is to provide a detection device capable of obtaining good detection accuracy.

Means for Solving the Problems

[0007] A detection device according to an aspect of the present disclosure includes an optical sensor including a plurality of light detection elements arranged in a planar shape, a light guide plate arranged to overlap one side in a first direction with respect to the optical sensor and having translucency, a light source arranged adjacent to the light guide plate in a second direction intersecting the first direction and irradiating light on a side surface of the light guide plate, and a plurality of light scatterers arranged between the optical sensor and the light guide plate so as not to overlap with the light detection elements when viewed from the first direction and scattering the light propagating in the light guide plate. The light scatterer is an integrally molded product separate from the light guide plate and is provided in a state of being in contact with the light guide plate.

Brief Description of the Drawings

[0008]

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DETAILED DESCRIPTION OF THE INVENTION

[0009] A mode (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present disclosure is not limited by the content described in the following embodiments. Further, the constituent elements described below include those that can be easily assumed by those skilled in the art and substantially identical ones. Furthermore, the constituent elements described below can be combined as appropriate. Note that the disclosure is merely an example, and those that can be easily conceived by those skilled in the art with appropriate modifications while maintaining the gist of the present disclosure are naturally included in the scope of the present disclosure.

[0010] In addition, for the purpose of making the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual aspect, but this is merely an example and does not limit the interpretation of the present disclosure. Also, in the present disclosure and each figure, the same reference numerals are given to the same elements as those described above with respect to the previously shown figures, and detailed descriptions may be omitted as appropriate.

[0011] And in the drawings, the XYZ coordinates are such that the Z direction (first direction) is the vertical direction, the X direction (second direction) is the left - right direction, and the Y direction is the front - back direction. The X direction intersects (is orthogonal to) the Y direction and the Z direction, the Y direction intersects (is orthogonal to) the X direction and the Z direction, and the Z direction intersects (is orthogonal to) the X direction and the Y direction. The Z1 side is one side of the first direction, and the Z2 side is the other side of the first direction. The X2 side is one side of the second direction, and the X1 side is the other side of the second direction.

[0012] [First Embodiment] First, the first embodiment will be described. FIG. 1 is a schematic diagram showing a cross - section of a detection device according to the first embodiment. FIG. 2 is a schematic diagram showing a part of the cross - section of the detection device according to the first embodiment. FIG. 3 is a schematic diagram showing a part of FIG. 2. FIG. 4A is a plan view of FIG. 1. FIG. 4B is a cross - sectional view taken along line IVB - IVB of FIG. 4A.

[0013] As shown in FIG. 1, the detection device 100 includes a front light FL, a sensor substrate 4, a light scatterer 30, and a microlens 43. The front light FL includes a light guide plate 2 and a light source device 7, and the sensor substrate 4 includes an optical sensor 81 and an optical filter 82. That is, in other words, the detection device 100 includes a light guide plate 2, a light source device 7, an optical sensor 81, an optical filter 82, a light scatterer 30, and a microlens 43. Note that the object 114 indicated by the virtual line is disposed on the Z1 side (upper side, one side in the first direction) of the light guide plate 2. Various objects can be applied to the object 114, including containers such as petri dishes and culture media, which will be described later.

[0014] As shown in FIG. 1, the light guide plate 2 is disposed to overlap the sensor substrate 4 on the Z1 side. The light guide plate 2 has translucency. The light guide plate 2 is a flat member. The light guide plate 2 has a first surface 21, a second surface 22, and a side surface 23. The first surface 21 is the surface on the Z2 side, and the second surface 22 is the surface on the side opposite to the first surface 21 (i.e., the Z1 side). The side surface 23 is located on the X1 side.

[0015] The light source device 7 faces the side surface 23 of the light guide plate 2. The light source device 7 is located on the X1 side with respect to the side surface 23 of the light guide plate 2. The light source device 7 irradiates the side surface 23 of the light guide plate 2 with light 120. The light source device 7 includes, for example, a light source 71 that is a plurality of light emitting diodes (LEDs: Light Emitting Diodes). That is, a plurality of light sources 71 are arranged along the Y direction and are disposed to face the side surface 23 of the light guide plate 2.

[0016] As shown in FIGS. 1 and 2, the sensor substrate 4 includes a first translucent plate 41, a second translucent plate 42, an optical sensor 81, and an optical filter 82. The first translucent plate 41 and the second translucent plate 42 are flat members having translucency. The second translucent plate 42 is laminated on the upper side of the first translucent plate 41. The first translucent plate 41 has an upper surface 41a and a lower surface 41b. The second translucent plate 42 has an upper surface 42a and a lower surface 42b.

[0017] As shown in FIG. 3, an optical sensor 81 and an optical filter 82 are provided on the first light-transmitting plate 41. The optical filter 82 is an optical element that transmits, toward the optical sensor 81, a component of the light 120 reflected by the object 114 and traveling in the Z2 direction. The optical filter 82 includes a light guide path 821 and a light-shielding portion 822. The light guide path 821 includes a light guide path 821a and a light guide path 821b. The light-shielding portion 822 includes a light-shielding portion 822a and a light-shielding portion 822b. The light guide path 821a and the light-shielding portion 822a are arranged at the end portion on the Z1 side of the first light-transmitting plate 41 and extend in the X direction and the Y direction. The light guide path 821b and the light-shielding portion 822b are arranged at the end portion on the Z2 side of the first light-transmitting plate 41 and extend in the X direction and the Y direction. When viewed from the Z direction, the light guide path 821a overlaps with the light guide path 821b. The widths of the light guide path 821a in the X direction and the Y direction are larger than the widths of the light guide path 821b in the X direction and the Y direction. Therefore, the optical path 122 from the light guide path 821a toward the light guide path 821b becomes narrower as it goes in the Z2 direction. Thus, the optical filter 82 is an optical element that shields a component traveling in an oblique direction. The optical filter 82 is also called a collimating aperture, a louver, or a collimator.

[0018] Note that the optical sensor 81 is divided into a plurality of photodiodes 813 (sensor pixels 812). Specifically, the photodiodes 813 are PIN (Positive Intrinsic Negative) photodiodes or organic photodiodes (OPD: Organic Photodiode) using an organic semiconductor. More specifically, as shown in FIG. 3, one photodiode 813 is disposed opposite to the light guide path 821b on the Z2 side.

[0019] As shown in FIGS. 1 and 2, the microlens 43 is provided on the upper surface 42a of the second light-transmitting plate 42. The microlens 43 is a hemispherical light-transmitting member that protrudes from the upper surface 42a toward the Z1 side. That is, when viewed in the Z direction, the microlens 43 has a circular shape. The microlens 43 focuses the light 120 from the object 114 onto the photodiode 813. When viewed in the Z direction, the microlens 43 overlaps with the light guide paths 821a, 821b, and the photodiode 813 shown in FIG. 3.

[0020] The light scatterer 30 is, for example, a white resist 31. The white resist 31 scatters a part of the light 120 propagating in the light guide plate 2. The white resist 31 is applied to the upper surface 42a of the second light-transmitting plate 42. The white resist 31 has, for example, a columnar shape extending in the Z direction.

[0021] Also, as shown in FIGS. 4A and 4B, the density of the white resist 31, which is the light scatterer 30, increases as it gets farther from the light source 71. In other words, the density of the white resist 31 increases as it goes from the X1 side to the X2 side. Specifically, as shown in FIG. 4A, the number of white resists 31 included in a region of the same area increases as it goes to the X2 side. That is, when viewed in the Z direction, the light guide plate 2 has a first region R1 and a second region R2 of the same area that are separated from the light source 71 toward the X2 side (one side of the second direction), the second region R2 is located on the X2 side of the first region R1, and the number of white resists 31 included in the second region R2 is larger than the number of white resists 31 included in the first region R1.

[0022] Note that the black resist 32 absorbs a part of the light 120 propagating in the light guide plate 2. The black resist 32 is applied to the upper surface 42a of the second light-transmitting plate 42 and has a columnar shape extending in the Z direction. The black resist 32 is, for example, the spacer 52 between the light guide plate 2 and the sensor substrate 4. As shown in FIG. 1, the black resist 32 is in contact with the first surface 21 of the light guide plate 2 and the upper surface 42a of the second light-transmitting plate 42. Further, as shown in FIGS. 4A and 4B, the density of the plurality of spacers 52 increases as it approaches the light source 71. That is, as shown in FIG. 4A, when viewed from the Z direction, the light guide plate 2 has a first region R1 and a second region R2 of the same area separated from the light source 71 toward the X2 side (one side in the second direction), the second region R2 is located on the X2 side of the first region R1, and the number of black resists 32 (spacers 52) included in the first region R1 is larger than the number of black resists 32 (spacers 52) included in the second region R2.

[0023] FIG. 5 is a block diagram showing a configuration example of the detection device according to the first embodiment. As shown in FIG. 5, the detection device 100 includes an optical sensor 81, a light source device 7, and a host IC 75 that controls the light source device 7. The optical sensor 81 includes an array substrate 811, a plurality of sensor pixels 812 (photodiodes 813) formed on the array substrate 811, gate line drive circuits 814A and 814B, a signal line drive circuit 815A, and a detection control circuit 816.

[0024] The array substrate 811 is formed with the substrate as a base. Each of the plurality of sensor pixels 812 includes a photodiode 813, a plurality of transistors, and various wirings.

[0025] The array substrate 811 has a detection region AA and a peripheral region GA. The detection region AA is a region where a plurality of sensor pixels 812 (a plurality of photodiodes 813) are provided. The peripheral region GA is a region between the outer periphery of the detection region AA and the outer edge of the array substrate 811, and is a region where no plurality of sensor pixels 812 are provided. The gate line drive circuits 814A and 814B, the signal line drive circuit 815A, and the detection control circuit 816 are provided in the peripheral region GA.

[0026] The plurality of sensor pixels 812 are each an optical sensor having a photodiode 813 as a sensor element. The photodiodes 813 each output an electrical signal corresponding to the light irradiated thereon.

[0027] The detection control circuit 816 is a circuit that supplies control signals Sa, Sb, and Sc to the gate line drive circuits 814A and 814B and the signal line drive circuit 815A, respectively, to control their operations. The detection control circuit 816 includes a signal processing circuit that performs signal processing on the detection signals Vdet from the plurality of photodiodes 813.

[0028] The detection control circuit 816 performs signal processing on the detection signals Vdet from the plurality of photodiodes 813 and outputs a sensor value So based on the detection signals Vdet to the host IC 75. Thereby, the detection device 100 detects information regarding the detected object 114.

[0029] The light source device 7 includes a light source 71 and a light emitting element control circuit 74.

[0030] As described above, the plurality of light sources 71 are positioned to face the side surface 23 of the light guide plate 2. The plurality of light sources 71 are driven by switching between on (lit state) and off (unlit state) according to a command Sd from the light emitting element control circuit 74.

[0031] The host IC 75, as a control circuit on the optical sensor 81 side, includes a sensor value storage circuit 751, a sensor value calculation circuit 752, a light amount setting circuit 753, a target value storage circuit 759, a storage circuit 757, and a host PC 758. The sensor value storage circuit 751 stores the sensor value So output from the detection control circuit 816 of the optical sensor 81. The sensor value calculation circuit 752 performs predetermined arithmetic processing on the sensor value So of the photodiode 813.

[0032] In the light quantity setting mode, the light quantity setting circuit 753 compares the sensor value So detected by the plurality of photodiodes 813 with the preset target sensor value So-t acquired from the target value storage circuit 759, and sets the light quantity for detecting the plurality of light sources 71. The target value storage circuit 759 stores the preset target sensor value So-t.

[0033] The host IC 75 has a lighting pattern generation circuit 754 and a lighting pattern storage circuit 755 as control circuits on the light source device 7 side. The lighting pattern storage circuit 755 stores information on the light quantity of each of the plurality of light sources 71 in the light quantity setting mode.

[0034] The lighting pattern generation circuit 754 generates various control signals based on the information on the light quantity in the lighting pattern storage circuit 755. The image generation circuit 756 generates an image of the object 114 based on the sensor value So output from the plurality of photodiodes 813 in the detection mode. The host IC 75 further has a storage circuit 757.

[0035] Next, the manufacturing procedures of the white resist 31, the black resist 32, and the microlens 43 will be described. FIG. 6 is a schematic diagram showing the manufacturing process of the detection device according to the first embodiment.

[0036] As shown in step a of FIG. 6, first, a sensor substrate large board 40 provided with a plurality (four in this embodiment) of sensor substrates 4 is prepared. That is, one sensor substrate large board 40 includes four unit sensor substrates 40A. As described above, the sensor substrate 4 includes the stacked first light-transmitting plate 41 and the second light-transmitting plate 42, and the photodiode 813 is formed on the first light-transmitting plate 41.

[0037] Next, as shown in steps b and c, a film-like black resist 32 is applied to the upper surface 42a of the second light-transmitting plate 42, and a plurality of black resists 32 shown in step c are provided by irradiating, for example, laser light 123 to the locations where the black resist 32 is desired to be left as shown in FIG. 12 described later.

[0038] Next, as shown in steps d and e, a film-shaped white resist 31 is applied to the upper surface 42a of the second light-transmitting plate 42, and a plurality of white resists 31 shown in step e are provided by irradiating, for example, laser light 123 on the portions where the white resist 31 is to be left as shown in FIG. 11 described later.

[0039] Next, as shown in steps f and g, a film-shaped lens resin 430 is applied to the upper surface 42a of the second light-transmitting plate 42, and a plurality of microlenses 43 shown in step g are provided by irradiating, for example, light on the portions where the microlenses 43 are to be left.

[0040] After the sensor substrate 4 is created as described above, as shown in FIG. 1, the light guide plate 2 is attached above the sensor substrate 4, and the light source 71 is arranged on the side of the light guide plate 2, whereby the detection device 100 according to the first embodiment is completed. Therefore, the white resist 31 and the black resist 32 are joined to the upper surface 42a of the second light-transmitting plate 42, and the light guide plate 2 is merely in contact with the first surface 21.

[0041] As described above, the detection device 100 according to the present embodiment includes an optical sensor 81 including a plurality of photodiodes 813 (light detection elements) arranged in a planar shape, a light guide plate 2 arranged to overlap on the Z1 side of the optical sensor 81, a light source 71, and a plurality of light scatterers 30. The light scatterer 30 is an integrally molded product separate from the light guide plate 2 and is provided in a state of being in contact with the light guide plate 2.

[0042] When the light 120 that is incident from the side of the light guide plate 2 and propagates through the light guide plate 2 hits the light scatterer 30, the light 120 is scattered by the light scatterer 30. A part of the scattered light 121 exits through the light guide plate 2 toward the object to be detected 114, and the light from the object to be detected 114 enters the plurality of photodiodes 813 through the light guide plate 2.

[0043] Therefore, when compared with the embodiment of providing a light diffusion structure with a triangular cross-section on the surface of the light guide plate 2 on the photodiode side described in the background art, in this embodiment, the light refracted when hitting the light diffuser 30 is less likely to enter the photodiode 813. Therefore, according to this embodiment, it is possible to provide a detection device 100 capable of obtaining good detection accuracy.

[0044] The number of white resists 31 (light diffusers 30) included in the second region R2 is larger than the number of white resists 31 included in the first region R1.

[0045] The amount of light 120 propagating through the light guide plate 2 decreases as the distance from the light source 71 increases. Also, by increasing the density of the light diffusers 30 as the distance from the light source 71 increases, the amount of light 120 scattered by the light diffusers 30 in the region far from the light source 71 increases. Therefore, when the light guide plate 2 is viewed from the Z direction, the amount of scattered light 120 is more evenly distributed over the entire region of the light guide plate 2.

[0046] The number of black resists 32 (spacers 52) included in the first region R1 is larger than the number of black resists 32 (spacers 52) included in the second region R2.

[0047] By using the white resist 31 as the light diffuser 30 and the black resist 32 as the spacer 52, as shown in FIG. 4A, when the light guide plate 2 is viewed from the Z direction, more white resists 31 can be arranged at the site far from the light source 71.

[0048] A light filter 82 having a light guide path 821 and a light shielding portion 822 is provided between the light guide plate 2 and the optical sensor 81. When viewed from the Z direction, the light guide path 821 overlaps with the photodiode 813.

[0049] Since the light 120 passing through the light guide plate 2 from the object 114 is likely to enter the plurality of photodiodes 813 through the light guide path 821, it is possible to obtain good detection accuracy.

[0050] The microlens 43 is arranged in the X direction with respect to the light diffuser 30.

[0051] In other words, since the microlens 43 and the light diffuser 30 are arranged side by side when viewed from the Z direction, the thickness of the detection device 100 in the Z direction becomes smaller.

[0052] It includes an optical filter 82 that limits the light entry path to the photodiode 813.

[0053] By providing the optical filter 82, the light incident on one photodiode 813 can be limited, so that good detection accuracy can be obtained.

[0054] [Second Embodiment] Next, the second embodiment will be described. FIG. 7 is a schematic diagram showing a detection device according to the second embodiment.

[0055] In the detection device 100 according to the first embodiment described above, the white resist 31 and the black resist 32 are joined to the upper surface 42a of the second light-transmitting plate 42, and are merely in contact with the first surface 21 of the light guide plate 2.

[0056] On the other hand, in the detection device 100A according to the second embodiment, the white resist 31 and the black resist 32 are joined to the first surface 21 of the light guide plate 2, and are merely in contact with the upper surface 42a of the second light-transmitting plate 42.

[0057] That is, according to the procedure shown in FIG. 6 above, after applying the white resist 31 and the black resist 32 to the first surface 21 of the light guide plate 2, as shown in FIG. 7, the light guide plate 2 provided with the white resist 31 and the black resist 32 is attached to the sensor substrate 4.

[0058] As described above, in the detection device 100A according to the present embodiment, similar to the first embodiment, the light scatterer 30 is an integrally molded product separate from the light guide plate 2 and is provided in contact with the light guide plate 2. Therefore, since the light 120 refracted when hitting the light scatterer 30 is less likely to enter the photodiode 813, according to the present embodiment, it is possible to provide a detection device capable of obtaining good detection accuracy.

[0059] [First Modification Example] Next, the first modification example will be described. FIG. 8 is a schematic diagram showing a detection device according to the first modification example. FIG. 9 is a schematic diagram showing a first light scatterer having the shape of a first taper. FIG. 10 is a schematic diagram showing a second light scatterer having the shape of a second taper. FIG. 11 is a schematic diagram showing a manufacturing process of a light scatterer using a white resist. FIG. 12 is a schematic diagram showing a manufacturing process of a light scatterer using a black resist. FIG. 13 is a plan view of the detection device according to the first modification example. FIG. 14 is a cross-sectional view taken along line XIV-XIV of FIG. 13.

[0060] In the first modification example, the light scatterer 30 includes a first light scatterer 33 and a second light scatterer 34. The first light scatterer 33 and the second light scatterer 34 are white resist 31. As shown in FIG. 9, the first light scatterer 33 is columnar extending in the Z direction and has the shape of a first taper 33A whose diameter increases as it approaches the light guide plate 2 (as it goes toward the Z1 side). The first light scatterer 33 has, for example, the shape of a frustum of a cone. The first light scatterer 33 has an upper surface 33a and a lower surface 33b. The upper surface 33a is in contact with the first surface 21 of the light guide plate 2. The lower surface 33b is in contact with the upper surface 42a of the second light-transmitting plate 42. As shown in FIG. 8, the first light scatterer 33 is formed on the upper surface 42a of the second light-transmitting plate 42. As shown in FIG. 11, after applying a white resist material 310 to the upper surface 42a of the second light-transmitting plate 42 and irradiating it with a laser beam 123, the irradiated portion reacts and the first light scatterer 33 is formed on the upper surface 42a by development.

[0061] Note that, as shown in FIG. 12, after applying a black resist material 320 to the upper surface 42a of the second light-transmitting plate 42, by irradiating laser light 123, the irradiated portion undergoes a reaction and the black resist 32 is formed on the upper surface 42a by development. The black resist 32 is, for example, columnar.

[0062] Also, as shown in FIG. 10, the second light-scattering body 34 is columnar extending in the Z direction and has a shape of a second taper 34A whose diameter decreases as it approaches the light guide plate 2 (as it goes toward the Z1 side). The second light-scattering body 34 has, for example, a frustum of a cone shape. The second light-scattering body 34 has an upper surface 34a and a lower surface 34b. The upper surface 34a is in contact with the first surface 21 of the light guide plate 2. The lower surface 34b is in contact with the upper surface 42a of the second light-transmitting plate 42. As shown in FIG. 8, the second light-scattering body 34 is formed on the first surface 21 of the light guide plate 2. The second light-scattering body 34 is formed by applying a white resist material 310 to the first surface 21 of the light guide plate 2 and then irradiating laser light 123.

[0063] As shown in FIGS. 13 and 14, when viewed from the Z direction, the light guide plate 2 has a first region R1 and a second region R2 of the same area that are separated from the light source 71 toward the X2 side (one side in the second direction). The second region R2 is located on the X2 side of the first region R1, and the number of the first light-scattering bodies 33 included in the second region R2 is larger than the number of the first light-scattering bodies 33 included in the first region R1. In other words, the density of the first light-scattering bodies 33 increases from the X1 side toward the X2 side.

[0064] As described above, in the detection device 100B according to the first modification, the light-scattering body 30 is columnar extending in the Z direction and includes a plurality of first light-scattering bodies 33 whose diameters increase as they approach the light guide plate 2.

[0065] For example, when compared with a columnar light-scattering body extending in the Z direction or a light-scattering body whose diameter decreases as it approaches the light guide plate 2, the area of the upper surface of the first light-scattering body 33 in contact with the light guide plate 2 is larger. Therefore, according to the present embodiment, the amount of light scattered on the upper surface of the first light-scattering body 33 is larger.

[0066] Further, the light diffuser 30 includes a first light diffuser 33 and a plurality of second light diffusers 34 that are columnar and extend in the Z direction and whose diameter decreases as they approach the light guide plate 2. The density of the first light diffuser 33 increases as it moves away from the light source 71, and the density of the second light diffuser 34 increases as it approaches the light source 71.

[0067] The area of the upper surface of the first light diffuser 33 in contact with the light guide plate 2 is larger than the area of the upper surface of the second light diffuser 34 in contact with the light guide plate 2. The amount of light scattered by the first light diffuser 33 is greater than the amount of light scattered by the second light diffuser 34. Here, the amount of light 120 propagating through the light guide plate 2 decreases as it moves away from the light source 71. Therefore, when the light guide plate 2 is viewed from the Z direction, the amount of scattered light 120 is more evenly distributed over the entire area of the light guide plate 2.

[0068] [Second Modification Example] Next, the second modification example will be described. FIG. 15 is a schematic diagram showing a detection device according to the second modification example.

[0069] The second modification example is different from the first embodiment in that a reflective film 45 is provided on the upper surface of the black resist 32. This will be briefly described below. As shown in the upper part of FIG. 15, the white resist 31 and the black resist 32 are joined to the upper surface 42a of the second light-transmitting plate 42, and a reflective film 45 is formed on the upper surface of the black resist 32 by coating. Then, the light guide plate 2 is attached from above the sensor substrate 4. Therefore, the white resist 31 and the reflective film 45 merely abut against the first surface 21 of the light guide plate 2.

[0070] As described above, in the detection device 100B according to the second modification example, the reflective film 45 is provided on the upper surface of the black resist 32. The black resist 32 absorbs the light 120, but by providing the reflective film 45 on the black resist 32, the location where the black resist 32 is disposed also reflects (scatters) the light 120.

[0071] [Third Modification Example] Next, the third modification example will be described. FIG. 16 is a schematic diagram showing a detection device according to the third modification example.

[0072] The third modification is different from the second embodiment in that a reflective film 45 is provided on the upper surface of the black resist 32. This will be briefly described below. As shown in the upper part of FIG. 16, the white resist 31 is joined to the first surface 21 of the light guide plate 2. A reflective film 45 is formed on the first surface 21 of the light guide plate 2, and a black resist 32 is formed on the Z2 side of the reflective film 45. Then, the light guide plate 2 is attached onto the sensor substrate 4. Therefore, the white resist 31 and the black resist 32 merely abut against the upper surface 42a of the second translucent plate 42.

[0073] As described above, also in the detection device 100C according to the third modification, the reflective film 45 is provided on the upper surface of the black resist 32. Since the black resist 32 absorbs the light 120, by providing the reflective film 45, the portion where the black resist 32 is disposed also reflects (scatters) the light 120.

[0074] [Third Embodiment] Next, the third embodiment will be described. FIG. 17 is a schematic diagram showing a detection device according to the third embodiment.

[0075] The detection device 100D according to the third embodiment includes a light-shielding layer 46 having an opening 48. This will be specifically described below.

[0076] The light-shielding layer 46 is provided between the photodiode 813 and the third translucent plate 47. The third translucent plate 47 is laminated below the first translucent plate 41. The photodiode 813 is laminated on the upper side of the light-shielding layer 46. The light-shielding layer 46 is provided with an opening 48. A light scatterer 30 that overlaps the opening 48 is provided when viewed in the Z direction. The light scatterer 30 is provided on the upper surface 42a of the second translucent plate 42. The light scatterer 30 does not overlap the photodiode 813 when viewed in the Z direction. The microlens 43 overlaps the photodiode 813 when viewed in the Z direction.

[0077] As described above, in the detection device 100D according to the third embodiment, the detection device 100D includes an optical sensor 81 including a plurality of photodiodes 813 (light detection elements) arranged in a planar shape, a light guide plate 2 arranged to overlap on the Z2 side of the optical sensor 81, a light source 71, and a light shielding layer 46 provided between the photodiode 813 and the light guide plate 2. The light shielding layer 46 has an opening 48.

[0078] By providing the opening 48 in the light shielding layer 46, the light traveling from the light guide plate 2 toward the object 114 to be detected can be limited to the light passing through the opening 48.

[0079] It includes a light scattering body 30 that overlaps with the opening 48 when viewed from the Z direction. According to this, the light traveling from the light guide plate 2 toward the object 114 to be detected can be passed through the opening 48 and scattered by the light scattering body 30.

[0080] The light scattering body 30 does not overlap with the photodiode 813 when viewed from the Z direction.

[0081] If the light scattering body 30 overlaps with the photodiode 813 when viewed from the Z direction, the light traveling from the object 114 to the photodiode 813 will be scattered by the light scattering body 30. Therefore, by making the light scattering body 30 non - overlapping with the photodiode 813 when viewed from the Z direction, the diffusion of the light traveling from the object 114 to the photodiode 813 by the light scattering body 30 is suppressed.

[0082] [Fourth Embodiment and Fourth Modification Example] Next, the fourth embodiment will be described. FIG. 18 is a schematic diagram showing a detection device according to the fourth embodiment. FIG. 19 is a schematic diagram showing a light guide plate according to the fourth modification example.

[0083] The detection device 100E according to the fourth embodiment has a light-transmitting plate 47A laminated on the lower side of the first light-transmitting plate 41, and a first diffusion portion 35 is provided on the lower surface of the light-transmitting plate 47A. The first diffusion portion 35 is a triangular notch recessed on the Z1 side (upper side) and viewed from the Y direction. That is, the first diffusion portion 35 has the shape of a prism. The first diffusion portion 35 faces an inclined surface 35a and a vertical surface 35b. The vertical surface 35b extends in the Z direction. The inclined surface 35a extends toward the middle between the Z1 side and the X2 side. The first diffusion portion 35 diffuses the light 120 propagating in the light guide plate 2 toward the Z1 side.

[0084] Also, a second diffusion portion 36 and a microlens 43 are provided on the upper surface 42a of the second light-transmitting plate 42. The second diffusion portion 36 overlaps with the opening 48 of the light-shielding layer 46 when viewed from the Z direction. The microlens 43 is arranged side by side with the second diffusion portion 36 in the X direction.

[0085] Then, a reflector 50 is arranged on the lower side of the light-transmitting plate 47A. The light 120 from the light source 71 passes through the light guide plate 2, hits the reflector 50 and is reflected, and then enters the light guide plate 2 again.

[0086] Also, in the fourth embodiment, the first diffusion portion 35 is directly formed on the lower surface of the light-transmitting plate 47A. However, as shown in FIG. 19 according to the fourth modification, the first diffusion portion 35 is formed on the lower surface of the light-transmitting plate 47C, and the light-transmitting plate 47C may be joined to the lower surface of the light-transmitting plate 47B via an adhesive layer 51.

[0087] As described above, in the fourth embodiment and the fourth modification, the detection device 100E includes an optical sensor 81 including a plurality of photodiodes 813 (light detection elements) arranged in a planar shape, a light guide plate 2 arranged to overlap on the Z2 side of the optical sensor 81, a light source 71, and a light-shielding layer 46 provided between the photodiodes 813 and the light guide plate 2. The light-shielding layer 46 has an opening 48. A first diffusion portion 35 for diffusing the light propagating in the light guide plate 2 toward the Z1 side is provided on the surface of the light guide plate 2 on the Z2 side.

[0088] Thus, since the first diffusing portion 35 is provided on the surface of the light guide plate 2 on the Z2 side, the light propagating in the light guide plate 2 can be diffused toward the Z1 side.

[0089] The detection device 100E includes a second diffusing portion 36 and a microlens 43. The microlens 43 is arranged in the X direction with respect to the second diffusing portion 36.

[0090] Since the second diffusing portion 36 is provided on the surface of the light guide plate 2 on the Z1 side, the light traveling toward the Z1 side through the light guide plate 2 can be diffused by the second diffusing portion 36.

[0091] The first diffusing portion 35 has the shape of a prism.

[0092] Thereby, the traveling direction of the light propagating through the light guide plate 2 can be changed by the first diffusing portion 35 to a direction toward the Z1 side.

[0093] The second diffusing portion 36 overlaps with the opening 48 when viewed from the Z direction.

[0094] Thereby, the light traveling from the light guide plate 2 toward the object to be detected 114 can pass through the opening 48 and be scattered by the second diffusing portion 36.

[0095] [Fifth Embodiment] Next, the fifth embodiment will be described. FIG. 20 is a schematic diagram showing a detection device according to the fifth embodiment. FIG. 21 is a schematic diagram showing the spreading state of diffracted light.

[0096] As shown in FIG. 20, in the detection device 100F according to the fifth embodiment, the light emitted from the upper surface 42a of the second light-transmitting plate 42 becomes diffracted light 120B. Hereinafter, the conditions for the diffracted light 120B will be described with reference to FIG. 21 and Table 1.

[0097] When the opening 48 shown in FIG. 21 is a circular opening 48 in plan view, the divergence angle θ 1 of the diffracted light 120A from the opening is represented by the following formula 1 that represents the size of the airy disk. Note that θ 1Here, θ is the divergence angle of the diffracted light 120A from the opening 48, λ is the wavelength of the incident light, and d is the diameter of the opening 48.

Number

[0098] Here, the opening 48 is present in a medium such as resin, and it is assumed that the diffracted light 120B exits from the medium into the air. The divergence angle of the diffracted light 120B in the air is represented by the following mathematical formula 2 according to Snell's law. Note that θ 0 is the divergence angle of the diffracted light 120B in the air, n 0 is the refractive index of air, and n 1 is the refractive index of the medium having the collimator.

Number

[0099] Therefore, the following mathematical formula 3 is derived.

Number

[0100] n 0 = 1.0, and assuming n 1 = 1.5, the divergence angle of the diffracted light 120B in the air is as shown in Table 1 below.

Table 1

[0101] Referring to Table 1, if the divergence angle of the light is too large, light loss due to reflection at the medium interface occurs. Conversely, if the divergence angle of the light is too small, the irradiation uniformity deteriorates. Therefore, the divergence angle of the diffracted light 120B is preferably 15 degrees or more and 65 degrees or less. From Table 1, the value of λ / d for which the divergence angle of the emitted light is 15 degrees or more and 65 degrees or less is 2.0 or more and 7.0 or less. Therefore, it can be seen that a value of λ / d of 2.0 or more and 7.0 or less is desirable.

[0102] As described above, in the fifth embodiment, the opening 48 is circular when viewed from the Z direction. The ratio of the wavelength λ of light to the diameter d of the opening 48 is 2.0 or more and 7.0 or less.

[0103] By setting the relationship between the diameter d of the opening 48 and the wavelength λ of light within this numerical range, the light emitted from the upper surface 42a of the second light-transmitting plate 42 into the air diffracts appropriately with a larger divergence angle.

[0104] [Sixth Embodiment] Next, the sixth embodiment will be described. FIG. 22 is a schematic diagram showing a detection device according to the sixth embodiment.

[0105] The detection device 100G according to the sixth embodiment is shown in FIG. 18 as a configuration obtained by removing the second diffusion part 36 from the detection device 100E according to the fourth embodiment. Therefore, the light 120 propagating in the light guide plate 2 diffuses toward the Z1 side at the first diffusion part 35 and passes through the opening 48. Here, since the diameter of the opening 48 satisfies the conditions described in the fifth embodiment, the light emitted from the upper surface 42a of the second light-transmitting plate 42 becomes diffracted light 120E.

[0106] As described above, in the sixth embodiment, since the diameter d of the opening 48 satisfies the conditions described in the fifth embodiment, the ratio of the wavelength λ of light to the diameter d of the opening 48 is 2.0 or more and 7.0 or less.

[0107] By setting the relationship between the diameter d of the opening 48 and the wavelength λ of light within this numerical range, the light emitted from the upper surface 42a of the second light-transmitting plate 42 into the air diffracts appropriately with a larger divergence angle.

[0108] [Fifth Modification Example] Next, the fifth modification example will be described. FIG. 23 is a schematic diagram showing a detection device according to the fifth modification example.

[0109] In the detection device 100H according to the fifth modification example, a mode is shown in which the microorganism 116 contained in the container 110 is applied as the object to be detected. The container 110 includes a mounting substrate 111 and a cover member 112. The container 110 is, for example, a petri dish. The container 110 has translucency. Note that the container 110 is arranged upside down with respect to a normal container. That is, in the container 110, the mounting substrate 111 is disposed on the upper side and the cover member 112 is disposed on the lower side. A culture medium 113 is provided on the lower side of the mounting substrate 111, and microorganisms 116 such as bacteria and cells are applied on the culture medium 115 (the lower surface of the culture medium 115).

[0110] As described above, according to the fifth modification example, the object to be detected 114 on which the microorganism 116 is applied on the culture medium 115 can be applied.

Description of Signs

[0111] 2 Light guide plate 4 Sensor substrate 21 First surface 22 Second surface 30 Light scatterer 31 White resist 32 Black resist (spacer) 33 First light scatterer 34 Second light scatterer 35 First diffusion part 36 Second diffusion part 43 Microlens 46 Light shielding layer 48 Opening 52 Spacer 71 Light source 81 Optical sensor 82 Optical filter 100, 100A, 100B, 100C, 100D, 100E, 100F, 100G Detection device 813 Photodiode (light detection element) 821 Light path

Claims

1. An optical sensor including a plurality of light detection elements arranged in a planar shape, a light guide plate that is arranged to overlap one side in a first direction with respect to the optical sensor and has translucency, a light source that is arranged adjacent to the light guide plate in a second direction intersecting the first direction and irradiates light onto a side surface of the light guide plate, and a plurality of light diffusers that are arranged between the optical sensor and the light guide plate so as not to overlap with the light detection elements when viewed from the first direction and scatter the light propagating in the light guide plate. A detection device.

2. When viewed from the first direction, the light guide plate has a first region and a second region of the same area that are separated from the light source toward one side in the second direction, the second region is located on one side in the second direction with respect to the first region, and the number of the light diffusers included in the second region is larger than the number of the light diffusers included in the first region. The detection device according to Claim 1.

3. The light diffuser is a first light diffuser that is columnar and extends in the first direction, and the diameter thereof increases as it approaches the light guide plate. The detection device according to Claim 2.

4. including a plurality of spacers arranged between the light guide plate and the optical sensor, when viewed from the first direction, the light guide plate has a first region and a second region of the same area that are separated from the light source toward one side in the second direction, the second region is located on one side in the second direction with respect to the first region, and the number of the spacers included in the first region is larger than the number of the spacers included in the second region. The detection device according to Claim 1.

5. The light diffuser includes a plurality of the first light diffusers, and a plurality of second light diffusers that are columnar and extend in the first direction, and the diameter thereof decreases as it approaches the light guide plate, when viewed from the first direction, the light guide plate has a first region and a second region of the same area that are separated from the light source toward one side in the second direction, the second region is located on one side in the second direction with respect to the first region, the number of the first light diffusers included in the first region is smaller than the number of the first light diffusers included in the second region, and the number of the second light diffusers included in the first region is larger than the number of the second light diffusers included in the second region. The detection device according to Claim 3.

6. A light filter having a light path and a light shielding portion is provided between the light guide plate and the optical sensor, and when viewed from the first direction, the light path overlaps with the light detection element. The detection device according to any one of claims 1 to 5.

7. Comprising a microlens that overlaps the light detection element when viewed from the first direction and focuses light traveling from the other side to the one side in the first direction toward the light detection element. The microlens is arranged in a second direction intersecting the first direction with respect to the light scatterer. The detection device according to claim 6.

8. An optical sensor including a plurality of light detection elements arranged in a planar shape, A light guide plate that is arranged to overlap the other side in the first direction with respect to the optical sensor and has light transmissivity, A light source that is arranged adjacent to the light guide plate in a second direction intersecting the first direction and irradiates light on a side surface of the light guide plate, And a light shielding layer provided between the light detection element and the light guide plate. The light shielding layer has an opening. Detection device.

9. The opening is circular when viewed from the first direction, The ratio of the wavelength λ of the light to the diameter d of the opening is 2.0 or more and 7.0 or less. The detection device according to claim 8.

10. Comprising a light diffuser that overlaps the opening when viewed from the first direction. The detection device according to claim 8.

11. Comprising an optical filter that limits the light entry path to the light detection element. The detection device according to any one of claims 8 to 10.

12. The light diffuser does not overlap the light detection element when viewed from the first direction. The detection device according to claim 10.

13. An optical sensor including a plurality of light detection elements arranged in a planar shape, A light guide plate that is arranged to overlap the other side in the first direction with respect to the optical sensor and has light transmissivity, A light source that is arranged adjacent to the light guide plate in a second direction intersecting the first direction and irradiates light on a side surface of the light guide plate, And a light shielding layer provided between the light detection element and the light guide plate. The light shielding layer has an opening. On the surface of the light guide plate on the other side in the first direction, a first diffusion portion is provided that diffuses the light propagating in the light guide plate toward the one side in the first direction. Detection device.

14. A second diffusion portion that is arranged on the one side in the first direction with respect to the optical sensor and diffuses the light toward the one side in the first direction, And a microlens that overlaps the light detection element when viewed from the first direction. The microlens is arranged in a second direction intersecting the first direction with respect to the second diffusion portion. The detection device according to claim 13.

15. The first diffusion part has a prism shape. The detection device according to claim 13 or 14. **Claim 16** The second diffusion part overlaps with the opening as viewed from the first direction. The detection device according to claim 14.

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