Air purification device

Abstract

To reduce a physical constitution of an air purifying device.SOLUTION: An air purifying device for purifying air flowing in a ventilation flue (120) includes light-emitting sections (300, 311, 321) and filters (24, 25). The light-emitting sections emit light. The filters are arranged on any one of an upstream side and a downstream side in a main direction of an air flow (AF) relative to the light-emitting sections in the ventilation flue, receive light emitted from the light-emitting sections, and allow air to pass. The filters have photocatalysts (26) activated by receiving light emitted from the light-emitting sections and purifying air passing the filters, and base materials (27) arranged with the photocatalysts. The base materials are net-shaped members.SELECTED DRAWING: Figure 20

Description

Technical Field

[0001] The present invention relates to an air purification device.

Background Art

[0002] Conventionally, a device for purifying air passing through a photocatalyst by activating a photocatalyst filter holding the photocatalyst by applying light thereto is known. For example, Patent Document 1 discloses a photocatalyst filter having a honeycomb structure.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, a photocatalyst filter having a honeycomb structure as described in Patent Document 1 tends to have a large dimension in the thickness direction, and as a result, the size of the air purification device becomes large.

[0005] In view of the above points, an object of the present invention is to reduce the size of an air purification device by devising its structure.

Means for Solving the Problems

[0006] The invention according to claim 1 for achieving the above object is In an air purification device that purifies air flowing through a ventilation path (120), A light-emitting unit (300) having a one-sided light-emitting unit (311) and a other-sided light-emitting unit (321) arranged opposite each other such that the main direction of light emitted from one-sided light-emitting unit and the main direction of light emitted from the other-sided light-emitting unit face each other. 、 A first filter (24) is positioned upstream of the main direction of the airflow (AF) that intersects the main direction of the light emitted from the light-emitting part within the ventilation passage, and receives the light emitted from the light-emitting part and allows air to pass through, and the first filter has a first photocatalyst (26) that is activated by receiving the light emitted from the light-emitting part and purifies the air passing through the filter, and a first substrate (27) which is a mesh-shaped member on which the first photocatalyst is arranged, A second filter (25) is positioned in the ventilation passage, facing the first filter on the downstream side of the main direction of the airflow that intersects the main direction of the light emitted from the light-emitting part, and receives the light emitted from the light-emitting part and allows air to pass through, and the second filter has a second photocatalyst (26) that is activated by receiving the light emitted from the light-emitting part and purifies the air passing through the second filter, and a second substrate (27) which is a mesh-shaped member on which the second photocatalyst is arranged, An intermediate filter (50) is positioned in the main direction of light emitted from a light-emitting part, receives light emitted from the light-emitting part, and allows air to pass through, and comprises an intermediate photocatalyst (26) that is activated by receiving light emitted from the light-emitting part and purifies the air passing through the intermediate filter, and an intermediate substrate (27) which is a mesh-shaped member on which the intermediate photocatalyst is arranged. The intermediate filter has one or more sections where the plate surface is positioned diagonally with respect to the main direction of light emitted from the light-emitting section. One-sided light-emitting section The intermediate filter and the intermediate filter are placed at a predetermined distance apart. Other side light-emitting section The intermediate filter is placed at a predetermined distance from the other filter. Between the light-emitting section and the intermediate filter, a first filter and a second filter are positioned on the upstream and downstream sides of the main direction of airflow, respectively.

[0007] In this way, by adopting a mesh-shaped component as the base material of the filter, the thickness dimension of the filter can be reduced, and consequently, the overall size of the air purification device can be reduced.

[0008] The reference numerals in parentheses attached to each component indicate an example of the correspondence between that component and the specific components described in the embodiments described later. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of the blower unit in the first embodiment. [Figure 2] This is an enlarged view of part II in Figure 1. [Figure 3] This is a cross-sectional view taken along line III-III in Figure 2. [Figure 4] This is a partially enlarged view of Figure 3. [Figure 5] This is a magnified view of a portion of the substrate. [Figure 6] This is a cross-sectional view taken from VI-VI in Figure 5. [Figure 7] This is a cross-sectional view taken along line VII-VII in Figure 5. [Figure 8] These are partial cross-sectional views of the upstream filter, downstream filter, and light guide rod. [Figure 9] This figure shows the downstream filter and additional filter in the second embodiment, and is a view taken from arrow IX in Figure 10. [Figure 10] Partial cross-sectional view of the upstream filter, downstream filter, additional filter, and light guide rod. [Figure 11] This is a cross-sectional view similar to Figure 3 in the third embodiment. [Figure 12] This figure shows the downstream filter and additional filter in the fourth embodiment in the same configuration as in Figure 9. [Figure 13] This figure shows the downstream filter and additional filter in the fifth embodiment in the same configuration as in Figure 9. [Figure 14] This figure shows the downstream filter in the sixth embodiment in the same configuration as in Figure 5. [Figure 15] This figure shows the downstream filter in the seventh embodiment in the same configuration as in Figure 5. [Figure 16] This is a cross-sectional view of a blower unit to which the air purification device according to the eighth embodiment is applied. [Figure 17] An enlarged view of part XVII in FIG. 16 [Figure 18] A view of the air purification device as seen in the direction of arrow XVIII in FIG. 17, excluding the upstream filter and the upper frame. [Figure 19] A sectional view taken along line XIX-XIX in FIG. 18. [Figure 20] A sectional view taken along line XX-XX in FIG. 18. [Figure 21] An enlarged view of part XXI in FIG. 20 [Figure 22] A sectional view taken along line XXII-XXII in FIG. 21. [Figure 23] A graph showing the experimental results of the relationship between the distance between the light-emitting part and the central filter and the air purification performance. [Figure 24] A diagram for explaining the mesh of the first filter and the second filter. [Figure 25] A diagram for explaining the mesh of the first filter and the second filter. [Figure 26] An enlarged view of the light-emitting part and the cylindrical lens included in the air purification device in the ninth embodiment, corresponding to the part in FIG. 22. [Figure 27] A view of the air purification device in the tenth embodiment, excluding the upstream filter, the upper frame, and the downstream filter. [Figure 28] A view of the air purification device in the eleventh embodiment, excluding the upstream filter, the upper frame, and the downstream filter. [Figure 29] A view of the air purification device in the twelfth embodiment, excluding the upstream filter, the upper frame, and the downstream filter. [Figure 30] A view of the air purification device in the thirteenth embodiment, excluding the upstream filter, the upper frame, and the downstream filter. [Figure 31] A view of the air purification device in the fourteenth embodiment, excluding the upstream filter, the upper frame, and the downstream filter. [Figure 32] A sectional view taken along line XXXII-XXXII in FIG. 31. [Figure 33] This is a cross-sectional view of the air purification device in the 15th embodiment, corresponding to the location shown in Figure 32. [Figure 34] This figure shows the air purification device according to the 16th embodiment, with the upstream filter, upper frame, and downstream filter removed. [Figure 35] This is a diagram illustrating the mesh of the first filter and the second filter in the air purification device according to the 17th embodiment. [Figure 36] This is a diagram illustrating the mesh of the first filter and the second filter in the air purification device according to the 18th embodiment. [Modes for carrying out the invention]

[0010] (First Embodiment) This embodiment will be described with reference to Figures 1-8. This embodiment is an example of applying the air purification device of this disclosure to a vehicle air conditioning system. The vehicle air conditioning system has an air conditioning unit (not shown) in addition to the blower unit 10. The blower unit 10 blows air to the air conditioning unit. The air conditioning unit adjusts the air blown from the blower unit 10 to a desired temperature and blows it into the vehicle interior. The air purification device of this disclosure is applied to the blower unit 10 of the vehicle air conditioning system. The blower unit 10 will be described below with reference to Figure 1.

[0011] As shown in Figure 1, the ventilation unit 10 has an air-inside-outside switching box 11 which serves as an air-inside-outside switching means for switching between introducing air inside the vehicle (i.e., internal air) and air outside the vehicle (i.e., outside air).

[0012] The internal / external air switching box 11 has an internal / external air casing 12 and an internal / external air door 13. The internal / external air casing 12 and the internal / external air door 13 are resin components made of polypropylene or the like.

[0013] The internal / external air casing 12 has an internal air inlet 121 for introducing internal air and an external air inlet 122 for introducing external air. The internal air inlet 121 and the external air inlet 122 are opened and closed by an internal / external air door 13. The internal / external air door 13 serves as a switching means for switching the air intake mode in the vehicle's air conditioning system. The intake modes that can be set are an internal air mode that introduces only internal air, an external air mode that introduces only external air, and an internal / external air mode that introduces both internal and external air simultaneously.

[0014] A blower 14 is located downstream of the internal / external air switching box 11. The blower 14 is a means of blowing air drawn in through the internal / external air switching box 11 towards the vehicle interior. The blower 14 is an electric blower in which a centrifugal fan 141 is driven by an electric motor 142. The centrifugal fan 141 is housed inside a scroll casing 143. The centrifugal fan 141 and the scroll casing 143 are resin components made of polypropylene or the like.

[0015] Furthermore, the air blowing unit 10 has a filter unit 20 provided between the internal / external air switching box 11 and the blower 14. The filter unit 20 purifies the air introduced from the internal / external air switching box 11. In this embodiment, the filter unit 20 constitutes the air purification device of this disclosure.

[0016] The filter unit 20 is located in the air passage 120 formed inside the inner and outer air casing 12. The filter unit 20 comprises a dust removal filter 21, a deodorizing filter 22, and a photocatalyst module 23. The filter unit 20 is arranged in the order of dust removal filter 21, photocatalyst module 23, and deodorizing filter 22 from upstream to downstream of the airflow AF in the air passage 120. That is, the dust removal filter 21, photocatalyst module 23, and deodorizing filter 22 are arranged in series with respect to the airflow AF in the air passage 120.

[0017] The dust removal filter 21, the deodorizing filter 22, and the photocatalyst module 23 are supported by support ribs 123, 124, and 125 formed on the inside of the internal / external air casing 12. The dust removal filter 21, the deodorizing filter 22, and the photocatalyst module 23 are detachably attached to the internal / external air casing 12 so that they can be cleaned or replaced when performing maintenance.

[0018] The dust removal filter 21 is a pre-filter that captures dust, dirt, pollen, etc., contained in the air. The dust removal filter 21 has a filter material made of a breathable sheet that is folded into a pleated shape, and end plates that reinforce the filter material. The filter material of the dust removal filter 21 is made of, for example, a nonwoven fabric made of resin.

[0019] The deodorizing filter 22 is a filter that deodorizes the air that has passed through the dust removal filter 21 and the photocatalytic module 23. The deodorizing filter 22 has a filter material made of a breathable sheet that is folded into a pleated shape, and end plates that reinforce the filter material. The filter material of the deodorizing filter 22 is made of a resin nonwoven fabric on which an adsorbent that adsorbs odor components is supported. Activated carbon, zeolite, and the like can be used as the adsorbent.

[0020] The photocatalytic module 23 deodorizes and disinfects the air. In the first embodiment, the photocatalytic module 23 has an upstream filter 24, a downstream filter 25, a light source device 30, and a frame 35, as shown in Figures 2 and 3. The thick arrow in Figure 3 indicates the direction in which light travels.

[0021] Frame 35 is a metal component, for example, that constitutes the outer shell of the photocatalytic module 23, and is supported by support ribs 123 and 124, as shown in Figure 2. Frame 35 supports the upstream filter 24, the downstream filter 25, and the light source device 30. More specifically, frame 35 surrounds the upstream filter 24, the downstream filter 25, and the light source device 30 from the outer periphery in a direction that intersects (e.g., orthogonal) the direction of the airflow AF from upstream to downstream. Furthermore, frame 35 covers a portion of the upstream side of the airflow AF with respect to the upstream filter 24, while leaving the other side open to the upstream side. Furthermore, frame 35 covers a portion of the downstream side of the airflow AF with respect to the downstream filter 25, while leaving the other side open to the downstream side.

[0022] As shown in Figure 2, the light source device 30 is positioned between the upstream filter 24 and the downstream filter 25, sandwiched between them. In the first embodiment, as shown in Figure 3, the light source device 30 has a one-sided substrate 31, a other-sided substrate 32, a plurality of one-sided light-emitting units 311, a plurality of other-sided light-emitting units 321, and a plurality of light guide rods 341. The light source device 30 generates light and emits it toward the upstream filter 24 and the downstream filter 25.

[0023] As shown in Figure 3, one side substrate 31 is positioned at one end of the frame 35 in a first direction D1 that intersects (for example, perpendicularly) the airflow AF from upstream to downstream. The other side substrate 32 is positioned at the other end of the frame 35 in the first direction D1. Both the one side substrate 31 and the other side substrate 32 are plate-shaped members and face each other in the first direction D1.

[0024] Each one-sided light-emitting unit 311 is a component that is fixedly attached to the side surface of the other-sided substrate 32 of the one-sided substrate 31, generates light, and emits light towards the other-sided substrate 32. The multiple one-sided light-emitting units 311 are arranged in a line that intersects (for example, perpendicularly) the airflow AF from upstream to downstream and along a second direction D2 that is perpendicular to the first direction D1. Each one-sided light-emitting unit 311 is composed of, for example, a UV-LED that emits light including ultraviolet light.

[0025] Each other-side light-emitting unit 321 is fixedly attached to the side surface of the one-side substrate 31 of the other-side substrate 32, generates light, and emits light towards the one-side substrate 31. The multiple other-side light-emitting units 321 are arranged in a line along the second direction D2. Each other-side light-emitting unit 321 is, for example, a UV-LED that emits light including ultraviolet light.

[0026] Each other-side light-emitting section 321 faces its corresponding one-side light-emitting section 311 in the first direction D1. The light emitted by each one-side light-emitting section 311 and each other-side light-emitting section 321 may or may not be directional.

[0027] Each of the multiple light guide rods 341 is attached to the surface of the downstream filter 25 that faces the upstream filter 24. Each light guide rod 341 is a rod-shaped member made of a light-transmitting material such as acrylic or glass. The light guide rods 341 correspond to the light guides.

[0028] As shown in Figure 3, each light guide rod 341 is positioned to extend in a first direction D1 between a corresponding one-side light-emitting section 311 and a corresponding other-side light-emitting section 321. Therefore, each light guide rod 341 extends from the corresponding one-side light-emitting section 311 to the corresponding other-side light-emitting section 321.

[0029] Multiple light guide rods 341 are arranged in the second direction D2, spaced apart from one another. Therefore, air can flow through the gaps between the multiple light guide rods 341 along the direction of airflow AF.

[0030] Light emitted from one side light-emitting section 311 enters the light guide rod 341 from the end of the light guide rod 341 on the side of the light guide rod 311, passes through the inside of the light guide rod 341, and then exits the light guide rod 341 to reach the upstream filter 24 and the downstream filter 25. Similarly, light emitted from the other side light-emitting section 321 enters the light guide rod 341 from the end of the light guide rod 341 on the side of the light guide rod 321, passes through the inside of the light guide rod 341, and then exits the light guide rod 341 to reach the upstream filter 24 and the downstream filter 25.

[0031] The configuration and operation of the light guide rod 341 will be explained in detail below using Figures 3 and 4. Note that Figure 4 is a partially enlarged view of Figure 3, but the downstream filter 25 is omitted. Also, the thick arrows in Figure 4 indicate the direction in which light travels. The light guide rod 341 is configured to reduce variations in the distribution of light that reaches the upstream filter 24 and the downstream filter 25 from the light incident on the light-emitting rod 341 from the light-emitting section 311 on one side and the light-emitting section 321 on the other side, with respect to the first direction D1.

[0032] As shown in Figures 3 and 4, in the light guide rod 341, a plurality of first prism portions 341d are formed on the first light guide surface 341c facing one side of the second direction D2, at predetermined intervals along the first direction D1. In addition, a plurality of second prism portions 341f are formed on the second light guide surface 341e facing the other side of the second direction D2, at predetermined intervals along the first direction D1. The first prism portions 341d and the second prism portions 341f are formed on the light guide rod 341 so as to be arranged alternately in the longitudinal direction of the light guide rod 341 (i.e., the first direction D1).

[0033] As shown in Figures 3 and 4, the first prism section 341d is formed to reflect light incident along the longitudinal direction of the light guide rod 341 from the one-side light-emitting section 311 and the other-side light-emitting section 321, and emit it in a direction toward the other side of the second direction D2. The second prism section 341f is also formed to reflect light incident along the longitudinal direction of the light guide rod 341 from the one-side light-emitting section 311 and the other-side light-emitting section 321, and emit it in a direction toward one side of the second direction D2.

[0034] Specifically, the first prism section 341d and the second prism section 341f are composed of grooves cut out so as to be recessed (for example, in a V-shape) in the second direction D2. The direction of the light emitted from the light guide rod 341 is determined by the orientation of the surface forming the groove. Therefore, in the cross-section of the first prism section 341d and the second prism section 341f cut by a plane parallel to the first direction D1 and the second direction D2, the first prism section 341d and the second prism section 341f intersect both the first direction D1 and the second direction D2. The first prism section 341d and the second prism section 341f may be composed of a plane or a curved surface. The first light guide surface 341c and the second light guide surface 341e may also be composed of a plane or a curved surface.

[0035] As shown in Figure 4, the light emitted from the one-side light-emitting section 311 enters the light guide rod 341 from the end of the light guide rod 341 on the side of the one-side light-emitting section 311, and then travels through the light guide rod 341 toward the other side in the longitudinal direction of the light guide rod 341 (i.e., the first direction D1). Furthermore, when the light enters the multiple first prism sections 341d from inside the light guide rod 341, it is reflected and travels toward the other side in the second direction D2, and then passes through the second light guide surface 341e to the outside of the light guide rod 341 and travels toward the other side in the second direction D2.

[0036] Furthermore, as shown in Figure 4, the light emitted from the one-side light-emitting section 311 enters the light guide rod 341 from the end of the light guide rod 341 on the side of the one-side light-emitting section 311, and then travels through the light guide rod 341 toward the other side in the longitudinal direction of the light guide rod 341. When the light enters the multiple second prism sections 341f from inside the light guide rod 341, it is reflected and travels toward one side in the second direction D2, and then passes through the first light guide surface 341c to the outside of the light guide rod 341 and travels toward one side in the second direction D2.

[0037] Furthermore, the light emitted from the other side light-emitting section 321 enters the light guide rod 341 from the end of the light guide rod 341 on the other side light-emitting section 321 side, and then travels through the light guide rod 341 toward one side in the longitudinal direction of the light guide rod 341. When the light enters the multiple first prism sections 341d from inside the light guide rod 341, it is reflected and travels toward the other side in the second direction D2, and then passes through the second light guide surface 341e and exits the light guide rod 341, traveling toward the other side in the second direction D2.

[0038] Furthermore, light emitted from the other side light-emitting section 321 enters the light guide rod 341 from the end of the light guide rod 341 on the other side light-emitting section 321 side, and then travels through the light guide rod 341 toward one side in the longitudinal direction of the light guide rod 341. When the light enters the multiple second prism sections 341f from inside the light guide rod 341, it is reflected and travels toward one side in the second direction D2, and then passes through the first light guide surface 341c and exits the light guide rod 341, traveling toward one side in the second direction D2.

[0039] As described above, multiple first prism sections 341d are arranged at intervals in the first direction D1 on the light guide rod 341. Also, multiple second prism sections 341f are arranged at intervals in the first direction D1 on the light guide rod 341. The light path corresponding to the arrow line in Figure 4, as described above, represents the principal direction of the light ray. In this embodiment, the principal direction of the light ray is the direction in which the light intensity is highest (i.e., the optical axis direction). Therefore, light also travels in directions slightly deviated from the direction of light corresponding to the arrow line in Figure 4, although the intensity is slightly lower than in the principal direction. For example, if the principal direction is directed to one side of the second direction D2 from the first light guide surface 341c of the light guide rod 341 as described above, light also travels in directions tilted in the direction of airflow AF and the opposite direction with respect to the direction of one side of the second direction D2. Furthermore, for example, if the main direction is directed from the second light guide surface 341e of the light guide rod 341 to the other side of the second direction D2 as described above, light will also propagate in the direction tilted in the direction of airflow AF and the opposite direction relative to the direction of one side of the second direction D2. As a result, the light emitted from the light guide rod 341 reaches the upstream filter 24 and the downstream filter 25. Note that the fact that the main direction is the direction in which light is emitted from the light source device 30 means that there is a bias in the directionality of the light emitted from the light source device 30.

[0040] Furthermore, as shown in Figure 4, on the side of the light guide rod 341 closer to the one-side light-emitting section 311 than the longitudinal center, the depth of the grooves in the first prism section 341d and the second prism section 341f in the second direction D2 increases as it moves away from the one-side light-emitting section 311. This makes it easier for light from the one-side light-emitting section 311 to reach the first prism section 341d and the second prism section 341f, which are farther away from the one-side light-emitting section 311.

[0041] Furthermore, on the side of the light guide rod 341 closer to the other side light-emitting section 321 than the longitudinal center, the depth of the grooves in the first prism section 341d and the second prism section 341f in the second direction D2 increases as it moves away from the other side light-emitting section 321. This makes it easier for light from the other side light-emitting section 321 to reach the first prism section 341d and the second prism section 341f, which are farther away from the other side light-emitting section 321.

[0042] As shown in Figures 2, 3, and 5, each of the upstream filter 24 and the downstream filter 25 has a photocatalyst 26 and a substrate 27. The photocatalyst 26 is a substance that purifies the surrounding air by being activated when it receives light generated and emitted by the light source device 30. The photocatalyst 26 is a powder of a metal oxide such as titanium dioxide or zinc oxide. The photocatalyst 26 and substrate 27 of the upstream filter 24 are referred to as the first catalyst and the first substrate. The photocatalyst 26 and substrate 27 of the upstream filter 24 correspond to the first catalyst and the first substrate, respectively. The photocatalyst 26 and substrate 27 of the downstream filter 25 correspond to the second catalyst and the second substrate, respectively.

[0043] The base material 27 is a mesh-shaped plate member with a thickness of less than 9 mm (for example, less than 5 mm). The base material 27 may be made of metal (for example, aluminum), resin, or other material.

[0044] For example, the base material 27 is art metal. Art metal is a mesh-like metal sheet made by cutting alternating cuts into a metal sheet using an art metal manufacturing machine, then pressing and expanding it to form rhombuses, hexagons, octagons, special shapes, etc.

[0045] A photocatalyst 26 is supported on the surface of the substrate 27. The photocatalyst 26 may be supported on the entire surface of the substrate 27 as shown in Figure 5, or it may be supported only on parts that are relatively easily exposed to light emitted from the light source device 30 and relatively easily in contact with the airflow AF (i.e., surfaces 271q and 271s, which will be described later).

[0046] The substrate 27 supports the photocatalyst 26 and also allows airflow AF to pass through, while reducing the amount of light emitted from the light source device 30 that leaks outside the photocatalyst module 23.

[0047] As shown in Figures 5, 6, and 7, the base material 27 has a plurality of strands 271 and a plurality of bonds 272. The plurality of strands 271 are members that extend in a strip-like manner. Most of the plurality of strands 271 are connected to one bond 272 at one end and to another bond 272 at the other end. The strands 271 located at the ends of the base material 27 have one end connected to one bond 272 and the other end is open.

[0048] Bond 272 is a component that acts as a node where multiple strands 271 are connected. Most of the multiple bonds 272 have four strands 271 connected to them. Bond 272 located at the end of the base material 27 have two strands 271 connected to them.

[0049] A gap enclosed by the smallest loop, which consists of two or more strands 271 and two or more bonds 272, corresponds to one mesh. The base material 27 has multiple such meshes (e.g., 50 or more). In Figure 5, four linear strands 271 and four bonds 272 form one rhombic mesh. In this way, the mesh shape of the base material 27 is formed by the connection structure of multiple strands 271 and multiple bonds 272.

[0050] Furthermore, on the surface of the base material 27, the ratio of the area occupied by the mesh gaps within the outer shape of the base material 27 to the total area within the outer shape of the base material 27 on the surface of the base material 27 is 50% or more. Therefore, compared to the case where this ratio is less than 50%, the pressure loss due to the airflow resistance of the air passing through the base material 27 is reduced. Note that the surface of the base material 27 refers to the surface (i.e., a virtual plane) that faces the thickness direction of the base material when the base material 27 is assumed to be a plate material with extremely small mesh.

[0051] The longitudinal direction L1 of this mesh is parallel to the first direction D1. Furthermore, the longitudinal direction L1 of this mesh intersects at a 90° angle with respect to the direction DL obtained by projecting the principal direction of light emitted from each light guide rod 341 onto the plate surface of the substrate 27. Of the multiple meshes that the substrate 27 has, the longitudinal direction L1 of all meshes may be parallel to the first direction D1, or only a portion (for example, 80% or more, 50% or more, 10% or more, etc.) may have the longitudinal direction L1 parallel to the first direction D1.

[0052] As shown in Figures 5, 6, and 7, each strand 271 has four sides 271a, 271b, 271c, and 271d extending in the longitudinal direction of the strand 271, and four faces 271p, 271q, 271r, and 271s extending in the longitudinal direction of the strand 271. The sides 271a, 271b, 271c, and 271d may be straight lines extending linearly in the longitudinal direction, or they may be curves that gently curve along the longitudinal direction.

[0053] Surface 271p is the surface connecting sides 271a and 271b, surface 271q is the surface connecting sides 271b and 271c, surface 271r is the surface connecting sides 271c and 271d, and surface 271s is the surface connecting sides 271d and 271a. Surfaces 271p, 271q, 271r, and 271s may be flat or gently curved surfaces. However, in a cross section perpendicular to the longitudinal direction of each strand 271, the radius of curvature of surfaces 271p, 271q, 271r, and 271s is greater than the radius of a circle having the same area as the strand 271 in that cross section.

[0054] Therefore, the cross-section of each strand 271 perpendicular to its longitudinal direction is a roughly quadrilateral, with sides 271a, 271b, 271c, and 271d each forming a corner. The radius of curvature of each corner in that cross-section is sufficiently smaller than the radius of curvature of any of the faces 271p, 271q, 271r, and 271s in that cross-section. For example, the radius of curvature of each corner is 1 / 10 or less of the smallest radius of curvature of the faces 271p, 271q, 271r, and 271s in that cross-section.

[0055] Most of each surface 271p and each surface 271r are surfaces formed by cuts in the metal sheet that makes up the base material 27, which is the art metal. The surface that was facing one side at the cut in the metal sheet that makes up the base material 27 becomes surface 271r after the base material 27 is formed. Also, the surface that was facing the other side at the cut in the metal sheet that makes up the base material 27 becomes surface 271p after the base material 27 is formed.

[0056] However, the surface 271r of the strand 271 at one end of the base material 27 in the second direction D2 corresponds to one side surface of the original metal plate from which the base material 27 is derived. Also, the surface 271p of the strand 271 at the other end of the base material 27 in the second direction D2 corresponds to the other side surface of the original metal plate from which the base material 27 is derived.

[0057] Furthermore, one side of the metal plate that forms the base material 27 is located at one end in the second direction D2 after the base material 27 is formed, and the other side of the metal plate is located at the other end in the second direction D2 after the base material 27 is formed.

[0058] Furthermore, each surface 271q corresponds to one side of the metal plate that forms the base material 27 (for example, the front side), and each surface 271s corresponds to the other side of the metal plate that forms the base material 27 (for example, the back side).

[0059] The operation of the vehicle air conditioning system configured as described above will be explained below. When the centrifugal fan 141 is rotated by the electric motor 142, air is introduced into the interior of the interior / exterior air casing 12 through at least one of the interior air inlet 121 and the exterior air inlet 122.

[0060] As shown in Figure 1, the airflow AF introduced into the inside of the internal / external air casing 12 flows into the filter unit 20 and is purified. Specifically, as the air flows into the dust removal filter 21, foreign matter such as dust, dirt, and pollen is removed.

[0061] The air from which foreign matter has been removed by the dust removal filter 21 passes through the photocatalyst module 23. Specifically, as shown by the arrows in Figure 8, the air passes through the mesh of the upstream filter 24, then through the gaps between the multiple light guide rods 341, and then through the mesh of the downstream filter 25. Figure 8 is a cross-sectional view of the upstream filter 24, the downstream filter 25, and a portion of the light guide rods 341, taken in a cross-section perpendicular to the first direction D1.

[0062] At this time, the light generated by the multiple one-sided light-emitting units 311 and the multiple other-sided light-emitting units 321 and emitted through the multiple light guide rods 341 irradiates the upstream filter 24 and the downstream filter 25, as shown by the arrows in Figure 8. This activates the photocatalyst 26 supported on the substrate 27 of the upstream filter 24 and the downstream filter 25. As a result, organic matter and bacteria that cause unpleasant odors in the air passing through the upstream filter 24 and the downstream filter 25 are oxidized and decomposed by the photocatalyst 26. Consequently, the air that passes through the upstream filter 24 and the downstream filter 25 is deodorized and sterilized. In other words, the air that passes through the upstream filter 24 and the downstream filter 25 is purified.

[0063] The air, which has been deodorized and sterilized by the upstream filter 24 and the downstream filter 25, passes through the deodorizing filter 22. In the deodorizing filter 22, odors that were not oxidatively decomposed by the upstream filter 24 and the downstream filter 25, as well as intermediate products generated by the photocatalyst 26, are adsorbed onto the adsorbent.

[0064] The air that flows into the filter unit 20 and is purified is then drawn into the centrifugal fan 141 and introduced into the air conditioning unit. The air introduced into the air conditioning unit is then adjusted to the desired temperature inside the unit and then blown into the vehicle interior. In this way, the air purified by the filter unit 20 is supplied to the vehicle interior as air conditioning air.

[0065] As described above, in the air purification device, the base material 27 constituting the upstream filter 24 is a mesh-shaped member. This makes it possible to reduce the dimensions of the upstream filter 24 in the thickness direction (i.e., the direction perpendicular to the plate surface direction), and consequently, to reduce the overall size of the air purification device.

[0066] (1) Furthermore, in the upstream filter 24 and the downstream filter 25, as shown in Figure 8, the surface 271q of each strand 271 is oriented toward the portion of the light-emitting light guide rod 341 located on one side of the strand 271 in the second direction D2. Therefore, in each strand 271, a portion of the light emitted from the light guide rod 341 located on one side of the strand 271 in the second direction D2 is irradiated onto the surface 271q of the strand 271 at an incident angle of less than 90°. This incident angle may be less than 45°. In that case, of the surfaces 271p, 271q, 271r, and 271s of the strand 271, the incident angle of the light incident from the light guide rod 341 onto surface 271q is the smallest.

[0067] Similarly, in the upstream filter 24 and the downstream filter 25, as shown in Figure 8, the surface 271s of each strand 271 is oriented toward the light guide rod 341 located on the other side of the second direction D2 from the strand 271. Therefore, in each strand 271, a portion of the light emitted from the light guide rod 341 located on the other side of the second direction D2 from the strand 271 is irradiated onto the surface 271s of the strand 271 at an incident angle of less than 90°. This incident angle may be less than 45°. In that case, of the surfaces 271p, 271q, 271r, and 271s of the strand 271, the incident angle of the light incident on surface 271s from the light guide rod 341 is the smallest.

[0068] As described above, each of the surfaces 271q and 271s of the strand 271 is oriented toward one of the multiple light guide rods 341. Therefore, compared to, for example, the case where the cross-section perpendicular to the longitudinal direction of the strand 271 is circular, the surface area upon which light is incident at a similar angle of incidence is wider. Consequently, the activation of the photocatalyst 26 supported on these surfaces 271q and 271s allows for stable air purification over a wider area. Furthermore, since light is incident on both the surfaces 271q and 271s of the strand 271 from one of the light guide rods 341 at an angle of incidence of less than 45°, the illuminance on the surfaces 271q and 271s of the strand 271 is relatively high.

[0069] (2) Furthermore, as shown in Figure 7, surface 271q is positioned at an angle to receive air flowing toward the upstream filter 24 and the downstream filter 25. An angle to receive air flowing toward the downstream filter 25 means that the angle between the normal direction of surface 271q and the direction downstream of the filter in the airflow AF is greater than 90° and less than 180°. In other words, a relatively wide surface 271q is oriented toward the direction of the airflow AF. Therefore, air that hits surface 271q flows along surface 271q. Consequently, for example, compared to the case where the cross section perpendicular to the longitudinal direction of the strand 271 is circular, the range over which delamination does not occur after air hits is wider. As a result, the air purification efficiency per unit area is increased on surfaces 271q and 271s of the substrate 27. The effect is even greater when the angle between the normal direction of surface 271q and the direction of the airflow AF is greater than 135°.

[0070] (3) Furthermore, in the upstream filter 24 and the downstream filter 25, the longitudinal direction L1 of some or all of the mesh of the substrate 27 intersects the direction DL, which is the direction of the main direction of light emitted from each light guide rod 341 projected onto the surface of the substrate 27. Therefore, compared to the case where the longitudinal direction L1 is parallel to the direction DL, the angle of incidence of light on the surfaces 271q and 271s of the strand 271 becomes relatively smaller, as shown in Figure 5. As a result, the illuminance on the strand 271 becomes relatively high. Consequently, the air purification efficiency per unit area of ​​the substrate 27 is increased.

[0071] (4) Furthermore, the light source device 30 is configured such that the main directions of the light emitted from the multiple light guide rods 341 intersect direction DL. That is, the light emitted from the light source device 30 has a bias in directionality, which increases the amount of light incident on the substrate 27 compared to when there is no bias in directionality. In this way, the air purification efficiency per unit area of ​​the substrate 27 is increased.

[0072] (5) In addition, in each light guide rod 341, a plurality of first prism sections 341d are arranged in a line with spacing in the first direction D1 on the light guide rod 341. Also, a plurality of second prism sections 341f are arranged in a line with spacing in the first direction D1 on the light guide rod 341. As a result, the light guide rod 341 guides the light generated by the one-side light-emitting section 311 and the other-side light-emitting section 321, thereby suppressing variations in the illuminance distribution in the first direction D1 on the substrate 27 generated by the one-side light-emitting section 311 and the other-side light-emitting section 321. If there were no light guide rod 341, the illuminance distribution on the substrate 27 would be high near the one-side light-emitting section 311 and the other-side light-emitting section 321 in the first direction D1, and low at positions equidistant from the one-side light-emitting section 311 and the other-side light-emitting section 321. Therefore, the light guide rod 341 can suppress variations in the air purification efficiency on the substrate 27.

[0073] (6) Furthermore, the base material 27 that constitutes the downstream filter 25 is also a mesh-shaped member. This makes it possible to reduce the dimensions of the downstream filter 25 in the thickness direction (i.e., the direction perpendicular to the plate surface direction), and consequently, to further reduce the size of the air purification device.

[0074] In this embodiment, the upstream filter 24 and the downstream filter 25 may correspond to the first filter and the second filter, respectively.

[0075] Furthermore, in this embodiment, the photocatalyst 26 and substrate 27 of the upstream filter 24 may correspond to the first photocatalyst and the first substrate, respectively, and the photocatalyst 26 and substrate 27 of the downstream filter 25 may correspond to the second photocatalyst and the second substrate, respectively. Alternatively, the photocatalyst 26 and substrate 27 of the upstream filter 24 may correspond to the second photocatalyst and the second substrate, respectively, and the photocatalyst 26 and substrate 27 of the downstream filter 25 may correspond to the first photocatalyst and the first substrate, respectively.

[0076] (Second Embodiment) Next, the second embodiment will be described using Figures 9 and 10. The photocatalytic module 23 in the air purification device of this embodiment has an additional filter 28 compared to the air purification device of the first embodiment. The other configurations are the same as in the first embodiment. Figure 9 is a view of the downstream filter 25 and the additional filter 28 of the photocatalytic module 23 as seen from the upstream side of the airflow AF, as shown by arrow IX in Figure 10. Figure 10 is a cross-sectional view of the photocatalytic module 23 of this embodiment, shown in the same form as in Figure 8. That is, Figure 10 is a cross-sectional view of the upstream filter 24, the downstream filter 25, the additional filter 28, and a part of the light guide rod 341 cut in a cross section perpendicular to the first direction D1. Note that in Figure 9, the photocatalyst 26 of the downstream filter 25 is omitted from the description.

[0077] As shown in Figures 9 and 10, in this embodiment, the additional filter 28 is positioned downstream of the downstream filter 25 in the direction of the airflow AF, and upstream of the deodorizing filter 22, facing the downstream filter 25.

[0078] The additional filter 28 has a photocatalyst 26 and a substrate 27 with the same configuration as in the first embodiment. However, as shown in Figure 9, the longitudinal direction L2 of each mesh in the substrate 27 of the additional filter 28 is shifted by 90° with respect to the longitudinal direction L1 of the substrate 27 of the downstream filter 25. In other words, the mesh of the substrate 27 constituting the additional filter 28 is different from the mesh of the substrate 27 constituting the upstream filter 24 and the downstream filter 25. More specifically, the orientation of the mesh of the substrate 27 constituting the additional filter 28 is different from the orientation of the mesh of the substrate 27 constituting the upstream filter 24 and the downstream filter 25. Note that the shape of the mesh of the substrate 27 constituting the additional filter 28 is the same as the shape of the mesh of the substrate 27 constituting the upstream filter 24 and the downstream filter 25.

[0079] (1) As described above, the additional filter 28 is positioned opposite the downstream filter 25, which prevents light emitted from the light source device 30 from leaking out of the photocatalyst module 23, resulting in high irradiation efficiency. This is because, as shown by the arrows in Figure 10 indicating the light emitted from the light guide rod 341, a portion of the light that has passed through the downstream filter 25 is irradiated onto the additional filter 28. Irradiation efficiency refers to the proportion of light emitted from the light source device 30 that plays a role in activating the photocatalyst 26.

[0080] (2) Furthermore, the mesh of the substrate 27 constituting the additional filter 28 is different from the mesh of the substrate 27 constituting the downstream filter 25, which is located on the same side as the light source device 30. Therefore, light emitted from the light source device 30 is less likely to leak out of the photocatalytic module 23.

[0081] In this embodiment, the upstream filter 24 corresponds to the second filter, the downstream filter 25 corresponds to the first filter, and the additional filter 28 corresponds to the third filter. Furthermore, the photocatalyst 26 and substrate 27 of the upstream filter 24 correspond to the second photocatalyst and the second substrate, respectively, while the photocatalyst 26 and substrate 27 of the downstream filter 25 correspond to the first photocatalyst and the first substrate, respectively.

[0082] (Third embodiment) Next, the third embodiment will be described using Figure 11. In this embodiment, the air purification device eliminates the multiple light guide rods 341 compared to the air purification devices of the first and second embodiments. Also, the multiple one-sided light-emitting units 311 and the multiple other-sided light-emitting units 321 have a narrower light distribution compared to the first and second embodiments. That is, the directional bias is greater. More specifically, each one-sided light-emitting unit 311 and each other-sided light-emitting unit 321 in this embodiment emits light with maximum intensity in a direction parallel to the plane formed by the first direction D1 and the second direction D2. The intensity of that light decreases as the angle with respect to the plane formed by the first direction D1 and the second direction D2 increases. As a result, the light irradiation intensity to the upstream filter 24, the downstream filter 25, and any additional filters 28 is improved compared to when there is no directional bias in each one-sided light-emitting unit 311 and each other-sided light-emitting unit 321. Consequently, the air purification efficiency per unit area in the upstream filter 24, the downstream filter 25, and any additional filter 28 is increased.

[0083] Alternatively, the light source device 30 may have multiple lenses. In this case, each of these lenses corresponds to one different light-emitting unit from the one-side light-emitting unit 311 and the other-side light-emitting unit 321. Each lens is then attached to the corresponding light-emitting unit, and the combination of lenses and light-emitting units makes it possible to achieve the narrow light distribution described above for the first and second embodiments.

[0084] (Fourth Embodiment) Next, a fourth embodiment will be described using Figure 12. Figure 12 is a view of the downstream filter 25 and additional filter 28 of the photocatalyst module 23 from the upstream side of the airflow AF. In Figure 12, the photocatalyst 26 of the downstream filter 25 is omitted from the description.

[0085] As shown in Figure 12, the air purification device of this embodiment is modified from the air purification device of the second embodiment by replacing the substance supported on the substrate 27 of the additional filter 28 from the photocatalyst 26 to substance 26a. Substance 26a is either zeolite or manganese. That is, substance 26a may contain only zeolite, only manganese, or both of the two.

[0086] (1) As described above, with substance 26a supported on the additional filter 28, intermediate products (e.g., aldehydes) from the oxidation reaction generated by the photocatalyst 26 in the upstream filter 24 and downstream filter 25 are adsorbed onto substance 26a in the additional filter 28. Therefore, the odor removal effect by intermediate products is improved.

[0087] In this embodiment, the upstream filter 24 corresponds to the first filter, and the additional filter 28 corresponds to the second filter. Alternatively, the upstream filter 24 corresponds to the first filter, the downstream filter 25 corresponds to the second filter, and the additional filter 28 corresponds to the third filter. In this embodiment, the substance 26a may contain a photocatalyst. In this embodiment, the deodorizing filter 22 may or may not be omitted.

[0088] (Fifth embodiment) Next, a fifth embodiment will be described using Figure 13. Figure 13 shows the downstream filter 25 and additional filter 28 of the photocatalytic module 23 as viewed from the upstream side of the airflow AF. In Figure 13, the photocatalyst 26 of the downstream filter 25 is omitted from the description.

[0089] As shown in Figure 13, in the air purification device of this embodiment, the substance supported on the base material 27 of the additional filter 28 is replaced from the photocatalyst 26 to vitamin 26b (for example, vitamin C) compared to the air purification device of the second embodiment.

[0090] (1) As described above, the additional filter 28 carries vitamin 26b, so when the air that has passed through the upstream filter 24 and the downstream filter 25 passes through the additional filter 28, it takes in vitamin 26b. Then, air containing vitamin 26b is blown into the vehicle interior, and an effect corresponding to the vitamin occurs in the vehicle interior. For example, if vitamin 26b is vitamin C, the moisture content of the occupants' skin increases. In other words, the occupants' skin is moisturized.

[0091] In this embodiment, the upstream filter 24 corresponds to the first filter, and the additional filter 28 corresponds to the second filter. Alternatively, the upstream filter 24 corresponds to the first filter, the downstream filter 25 corresponds to the second filter, and the additional filter 28 corresponds to the third filter. Furthermore, in this embodiment, the substrate 27 of the additional filter 28 may support a photocatalyst 26 in addition to vitamin 26b.

[0092] (Sixth Embodiment) Next, the sixth embodiment will be described with reference to Figure 14. In the air purification device of this embodiment, the substance supported on the substrate 27 of the downstream filter 25 is replaced from the photocatalyst 26 to substance 26a compared to the air purification device of the first embodiment. Substance 26a is either zeolite or manganese. That is, substance 26a may contain only zeolite, only manganese, or both of the two.

[0093] (1) As described above, with substance 26a supported on the downstream filter 25, intermediate products (e.g., aldehydes) from the oxidation reaction generated by the photocatalyst 26 in the upstream filter 24 are adsorbed onto substance 26a in the downstream filter 25. Therefore, the odor removal effect by intermediate products is improved.

[0094] In this embodiment, the upstream filter 24 corresponds to the first filter, and the downstream filter 25 corresponds to the second filter. In this embodiment, the substance 26a may contain a photocatalyst. In this embodiment, the deodorizing filter 22 may or may not be omitted.

[0095] (Seventh Embodiment) Next, the seventh embodiment will be described with reference to Figure 15. In the air purification device of this embodiment, the substance supported on the substrate 27 of the downstream filter 25 is replaced from the photocatalyst 26 to vitamin 26b (for example, vitamin C) compared to the air purification device of the second embodiment.

[0096] (1) As described above, vitamin 26b is supported on the downstream filter 25, so that when the air that has passed through the upstream filter 24 passes through the downstream filter 25, it takes in vitamin 26b. Then, air containing vitamin 26b is blown into the vehicle interior, and an effect corresponding to the vitamin occurs in the vehicle interior. For example, if vitamin 26b is vitamin C, the moisture content of the occupants' skin increases. In other words, the occupants' skin is moisturized.

[0097] In this embodiment, the upstream filter 24 corresponds to the first filter, and the downstream filter 25 corresponds to the second filter. In this embodiment, the substrate 27 of the downstream filter 25 may have a photocatalyst 26 supported on it in addition to vitamin 26b.

[0098] (Eighth embodiment) Next, the eighth embodiment will be described using Figures 16-25. The air purification device of the eighth embodiment is also an example of application to a vehicle air conditioning system. As shown in Figure 16, the vehicle air conditioning system has a blower unit 10. The configuration of the blower unit 10 is the same as that described in the first embodiment with reference to Figure 1.

[0099] An air passage 120 is formed inside the blower unit 10 through which air flows. In Figure 16, the main direction of the airflow AF in the air passage 120 is indicated by a dashed arrow. A filter unit 20 is positioned in the middle of the air passage 120. The filter unit 20 is equipped with a dust removal filter 21, a photocatalyst module 23, and a deodorizing filter 22 in this order, from upstream to downstream in the main direction of the airflow AF. In the eighth embodiment, the photocatalyst module 23 constitutes the air purification device of this disclosure.

[0100] In the description of the eighth embodiment and subsequent embodiments, the main direction of the airflow AF in the ventilation passage 120 may be referred to as the "vertical direction." Also, the first direction D1 used in the first to seventh embodiments is referred to as the "front-to-back direction." Also, the second direction D2 used in the first to seventh embodiments is referred to as the "lateral direction." The vertical direction is the direction in which the upstream filter 24 and the downstream filter 25 face each other. The front-to-back direction is the direction in which the multiple one-sided light-emitting units 311 and the multiple other-sided light-emitting units 321 face each other, or the main direction of the light emitted from each light-emitting unit 300. The lateral direction is the direction perpendicular to both the vertical direction and the front-to-back direction. In this specification, the terms vertical, lateral, front, back, up, and down are used for convenience of explanation and do not limit the state in which the air purification device and the vehicle air conditioning device are mounted on a vehicle.

[0101] The photocatalytic module 23 purifies the air flowing through the ventilation passage 120, specifically by deodorizing and sterilizing the air. The photocatalytic module 23 of the eighth embodiment includes a light-emitting unit 300, a cylindrical lens 40, an upstream filter 24, a downstream filter 25, an intermediate filter 50, etc., as shown in Figures 17 to 20. The arrows in Figures 18 to 22 indicate the direction in which light emitted from each light-emitting unit 300 is emitted through the cylindrical lens 40.

[0102] The upstream filter 24, the downstream filter 25, and the intermediate filter 50 receive the light emitted from the light-emitting unit 300 and allow air to pass through. The upstream filter 24 is positioned within the air passage 120 on the upstream side (i.e., one side in the vertical direction) of the main direction of airflow AF relative to the light-emitting unit 300. The upstream filter 24 is fixed to the upper frame 351.

[0103] On the other hand, the downstream filter 25 is positioned in the air passage 120, downstream of the main direction of airflow AF relative to the light-emitting section 300 (i.e., on the other side in the vertical direction), facing the upstream filter 24. The downstream filter 25 is fixed to the lower frame 352. The upstream filter 24 and the downstream filter 25 are positioned facing each other.

[0104] In the eighth embodiment, the upstream filter 24 corresponds to the first filter of this disclosure, and the downstream filter 25 corresponds to the second filter of this disclosure. However, the invention is not limited to this, and in this disclosure, the upstream filter 24 may correspond to the second filter of this disclosure, and the downstream filter 25 may correspond to the first filter of this disclosure.

[0105] As shown in the enlarged view of Figure 25, the upstream filter 24, the downstream filter 25, and the intermediate filter 50 all have a photocatalyst 26 and a substrate 27, similar to those described in the first embodiment. The photocatalyst 26 is a substance that is activated by receiving light emitted from the light-emitting unit 300 and purifies the air passing through the filter. The photocatalyst 26 is a powder of a metal oxide such as titanium dioxide or zinc oxide. The photocatalyst 26 in the upstream filter 24 is sometimes called the first photocatalyst, and the substrate 27 is sometimes called the first substrate. The photocatalyst 26 in the downstream filter 25 is sometimes called the second photocatalyst, and the substrate 27 is sometimes called the second substrate. In addition, the photocatalyst 26 in the intermediate filter 50 is sometimes called the intermediate photocatalyst, and the substrate 27 is sometimes called the intermediate substrate.

[0106] The base material 27 is in the shape of a mesh. For example, the base material 27 is art metal. Art metal is a mesh-shaped metal sheet made by cutting alternating cuts into a metal sheet using an art metal manufacturing machine and then spreading it out, forming the cuts into rhombuses, hexagons, octagons, special shapes, etc. The base material 27 has multiple strands 271 extending in a striated manner and multiple bonds 272 to which three or more strands are connected. The base material 27 supports the photocatalyst 26 and also allows airflow AF to pass through and reduces the amount of light emitted from the light-emitting part 300 that leaks out of the photocatalyst module 23.

[0107] The photocatalyst 26 is supported on the surface of the substrate 27. The photocatalyst 26 may be supported on the entire surface of the substrate 27, or it may be supported only on parts that are relatively easily exposed to light emitted from the light-emitting part 300 and are relatively easily exposed to the airflow AF (i.e., surfaces 271q and 271s described later).

[0108] The configurations of the upstream filter 24 and the downstream filter 25 are substantially the same as those described in the first embodiment, except for the orientation of the longitudinal direction L1 of the mesh shown in Figure 25. In the eighth embodiment, the upstream filter 24, the downstream filter 25, and the intermediate filter 50 are arranged such that the longitudinal direction L1 of the mesh is parallel to the transverse direction. However, the mesh of the upstream filter 24, the downstream filter 25, and the intermediate filter 50 is not limited to this and can be arranged arbitrarily.

[0109] Next, as shown in Figures 18 to 20, the light-emitting unit 300 is positioned between the upstream filter 24 and the downstream filter 25. The light-emitting unit 300 is a component that generates and emits light. The light-emitting unit 300 is composed of, for example, a UV-LED that emits light including ultraviolet light. However, the light-emitting unit 300 is not limited to this, and a visible light LED may also be used.

[0110] The light-emitting unit 300 has a plurality of one-sided light-emitting units 311 and a plurality of other-sided light-emitting units 321. The plurality of one-sided light-emitting units 311 and the plurality of other-sided light-emitting units 321 are arranged facing each other in the front-rear direction.

[0111] Multiple one-sided light-emitting units 311 are fixed to the one-sided substrate 31 and arranged side by side in the lateral direction. Therefore, the multiple one-sided light-emitting units 311 emit light radially to the area opposite to the one-sided substrate 31 (i.e., the other-sided substrate 32 side).

[0112] Multiple other-side light-emitting units 321 are fixed to the other-side substrate 32 and arranged side by side in the lateral direction. The multiple other-side light-emitting units 321 emit light radially in the area opposite to the other-side substrate 32 (i.e., towards the one-side substrate 31).

[0113] One side substrate 31 is fixed to one side of the lower frame 352 in the front-rear direction. The other side substrate 32 is fixed to the other side of the lower frame 352 in the front-rear direction. Both the one side substrate 31 and the other side substrate 32 are plate-shaped members and are arranged facing each other in the front-rear direction.

[0114] Multiple cylindrical lenses 40 are provided at positions corresponding to multiple light-emitting units 300. Each of the multiple cylindrical lenses 40 has multiple one-side cylindrical lenses 41 and multiple other-side cylindrical lenses 42. Multiple one-side cylindrical lenses 41 are provided at positions corresponding to multiple one-side light-emitting units 311. Multiple other-side cylindrical lenses 42 are provided at positions corresponding to multiple other-side light-emitting units 321.

[0115] When UV-LEDs are used in the light-emitting section 300, it is preferable to select silicone rubber, which is resistant to light degradation, as the material for the multiple cylindrical lenses 40. Alternatively, when visible light LEDs are used in the light-emitting section 300, acrylic or polycarbonate resins may be selected as the material for the multiple cylindrical lenses 40.

[0116] As shown in Figures 21 and 22, the cylindrical lens 40 has an inner surface 401 formed on the side facing the light-emitting part 300 and an outer surface 402 provided on the side opposite to the light-emitting part 300, both of which are part of a cylindrical shape. That is, as shown in Figure 21, the inner surface 401 and outer surface 402 of the cylindrical lens 40 are formed in an arc shape with a predetermined imaginary line parallel to the horizontal direction as the axis in a cross-sectional view perpendicular to the horizontal direction. The curvature of the inner surface 401 and outer surface 402 is set so that the light emitted from the light-emitting part 300 is refracted and the light is emitted from the outer surface 402 along the front-to-back direction. The cylindrical lens 40 also has protrusions 403 on one side and the other side in the vertical direction that project from the inner surface 401 toward the substrate side. The inclination angle of the surface of the protrusions 403 is set so that the light emitted from the light-emitting part 300 is refracted and totally reflected and the light is emitted from the outer surface 402 along the front-to-back direction. Furthermore, "light is emitted along the front-to-back direction" includes not only light being emitted parallel to the front-to-back direction, but also light being emitted at a steep, acute angle with respect to the front-to-back direction. Therefore, as shown by the solid arrows in Figure 21, the light emitted radially from the light-emitting unit 300 is emitted in a narrow range in the vertical direction via the cylindrical lens 40. As a result, as shown by the dashed arrows in Figure 21, light leakage from the upstream filter 24 and the downstream filter 25 can be reduced.

[0117] Furthermore, as shown in Figure 22, the inner surface 401 and outer surface 402 of the cylindrical lens 40 are planar in a cross-sectional view perpendicular to the vertical direction. Therefore, the light emitted radially from the light-emitting unit 300 is emitted so as to spread laterally through the cylindrical lens 40. Accordingly, as indicated by the arrows in Figures 21 and 22, in the eighth embodiment, the light emitted from the light-emitting unit 300 is configured to be oriented more widely in the later direction than in the vertical direction.

[0118] Next, as shown in Figures 18 and 20, the intermediate filter 50 is positioned between the upstream filter 24 and the downstream filter 25, in the principal direction of the light emitted from the light-emitting unit 300 through the cylindrical lens 40. The principal direction of light refers to the direction of the center of the light, the direction of the highest light intensity, or the direction of the optical axis. The intermediate filter 50, like the upstream filter 24 and the downstream filter 25, also has a photocatalyst 26 and a substrate 27. The substrate 27 of the intermediate filter 50 is also mesh-shaped. The substrate 27 is, for example, art metal. By positioning the intermediate filter 50 between the upstream filter 24 and the downstream filter 25, the light emitted from the light-emitting unit 300 between the upstream filter 24 and the downstream filter 25 can be effectively utilized by the photocatalyst 26 of the intermediate filter 50.

[0119] In the eighth embodiment, the intermediate filter 50 and the downstream filter 25 are formed integrally. Specifically, the intermediate filter 50 is formed by folding a portion of the downstream filter 25 multiple times in an M-shape (or, in other words, a mountain shape) toward the first filter. This does not increase the number of parts or assembly steps, thus reducing manufacturing costs. In Figure 18, the intermediate filter 50 and the downstream filter 25 are viewed from the upstream side in the main direction of the airflow AF, with valley folds indicated by dashed lines and mountain folds indicated by dashed lines. The number of mountains is determined according to the aperture ratio of the mesh shape of the intermediate filter 50, allowing light to be fully utilized in the central region in the front-to-back direction of the photocatalytic module 23. Furthermore, setting the intermediate filter 50 to an appropriate number of mountains increases the ventilation area and reduces ventilation resistance.

[0120] The intermediate filter 50 has a shape in which a part of the downstream filter 25 is folded multiple times in an M shape, and has multiple parts where the plate surface is positioned diagonally with respect to the main direction of light emitted from the light-emitting part 300. By positioning the plate surface of the intermediate filter 50 diagonally with respect to the main direction of light emitted from the light-emitting part 300, it is easier for the light emitted from the light-emitting part 300 to hit it, and also easier for the wind flowing from the upstream side to the downstream side through the air passage 120 to hit it. Therefore, since the wind hits the parts of the intermediate filter 50 where the photocatalytic reaction is occurring, the air purification effect can be enhanced. Note that the plate surface of the intermediate filter 50 refers to the surface (i.e., a virtual plane) that faces the thickness direction of the plate material when the intermediate filter 50 is assumed to be a plate material with extremely small mesh.

[0121] Furthermore, the cylindrical lens 40 and the intermediate filter 50 are arranged at a predetermined distance apart. That is, the light-emitting unit 300 and the intermediate filter 50 are arranged at a predetermined distance apart. If the light-emitting unit 300 and the intermediate filter 50 were arranged adjacent to each other, light would be strongly irradiated onto the inclined surface of the intermediate filter 50 adjacent to the light-emitting unit 300, preventing light from reaching the central region of the photocatalytic module 23 in the front-to-back direction. In contrast, by arranging the light-emitting unit 300 and the intermediate filter 50 at a predetermined distance apart, light reaches the central region of the photocatalytic module 23 in the front-to-back direction, and light is also irradiated onto the upstream filter 24 and the downstream filter 25, thereby enhancing the air purification effect. Note that even if the light-emitting unit 300 and the intermediate filter 50 are separated by a predetermined distance (for example, about 5 mm), light will still be irradiated onto the upstream filter 24 and the downstream filter 25, thus enhancing the air purification effect.

[0122] In Figure 20, the distance L between one cylindrical lens 41 and the intermediate filter 50, and the total distance LOA between one cylindrical lens 41 and the other cylindrical lens 42 are indicated by double arrows.

[0123] Here, we will explain the results of an experiment conducted on the relationship between the distance L between the light-emitting unit 300 and the intermediate filter 50 and the air purification performance of the photocatalytic module 23, referring to the graph in Figure 23.

[0124] The graph in Figure 23 shows the air purification performance of the photocatalytic module 23 described in the eighth embodiment above, with varying distances L between the light-emitting unit 300 and the intermediate filter 50, by flowing air containing a predetermined odor component from the upstream to the downstream side. Specifically, the air purification performance in this experiment is the deodorizing performance of the photocatalytic module 23. The horizontal axis of the graph in Figure 23 represents the distance L between the cylindrical lens 41 and the intermediate filter 50 as a percentage of the total length LOA between the cylindrical lens 41 and the cylindrical lens 42 on one side.

[0125] In this experiment, the number of peaks in the intermediate filter 50 of each prepared photocatalytic module 23 was kept the same. Therefore, for the photocatalytic modules 23 where the distance between the light-emitting section 300 and the intermediate filter 50 was 17% and 23%, the spacing between the multiple peak shapes on one side of the intermediate filter 50 (on the light-emitting section 311 side) and the multiple peak shapes on the other side (on the light-emitting section 321 side) was increased. Also, for the photocatalytic module 23 where the distance between the light-emitting section 300 and the intermediate filter 50 was 37%, the pitch of the multiple peak shapes in the intermediate filter 50 was made closer together compared to the one where the distance was 30%.

[0126] As shown in the graph in Figure 23, the best air purification performance is achieved when the distance between the light-emitting unit 300 and the intermediate filter 50 is 30% of the total distance. Next, the air purification performance is good when the distance between the light-emitting unit 300 and the intermediate filter 50 is 37%. Subsequently, the air purification performance is good when the distance between the light-emitting unit 300 and the intermediate filter 50 is 23% and 17%, respectively. Thus, the air purification performance is good for distances between 17% and 37% of the distance between the light-emitting unit 300 and the intermediate filter 50, and it improves further when the distance is between 23% and 37%, and further improves when it is between 30% and 37%.

[0127] However, in the photocatalytic module 23, the distance between the light-emitting unit 300 and the intermediate filter 50 is not limited to the above values. As described above, even if the light-emitting unit 300 and the intermediate filter 50 are separated by a predetermined distance (for example, about 5 mm), light is irradiated onto the upstream filter 24, the downstream filter 25, and the intermediate filter 50, thereby enhancing the air purification effect.

[0128] Next, as shown in Figure 24, in the upstream filter 24 and the downstream filter 25, the surface 271q of each strand 271 is oriented toward the one-side light-emitting unit 311 and the one-side cylindrical lens 41, which are located on one side in the front-rear direction relative to the strand 271. Therefore, a portion of the light emitted from the one-side light-emitting unit 311 is irradiated onto the surface 271q of the strand 271 at an incident angle of less than 90°. This incident angle may be less than 45°. In that case, of the surfaces 271p, 271q, 271r, and 271s of the strand 271, the incident angle of the light incident on surface 271q from the one-side light-emitting unit 311 is the smallest.

[0129] Similarly, in the upstream filter 24 and the downstream filter 25, the surface 271s of each strand 271 is oriented toward the other side light-emitting unit 321 and the other side cylindrical lens 42. Therefore, a portion of the light emitted from the other side light-emitting unit 321 is irradiated onto the surface 271s of the strand 271 at an incident angle of less than 90°. This incident angle may be less than 45°. In that case, of the surfaces 271p, 271q, 271r, and 271s of the strand 271, the incident angle of the light incident on surface 271s from the other side light-emitting unit 321 is the smallest.

[0130] As described above, each of the surfaces 271q and 271s of the strand 271 faces either the one-side light-emitting section 311 or the other-side light-emitting section 321. Therefore, compared to, for example, the case where the cross-section perpendicular to the longitudinal direction of the strand 271 is circular, the surface area on which light is incident at a similar angle of incidence is wider. Consequently, by activating the photocatalyst 26 supported on these surfaces 271q and 271s, the air can be stably purified over a wider area. In addition, since light is incident on both the surfaces 271q and 271s of the strand 271 from either the one-side light-emitting section 311 or the other-side light-emitting section 321 at an angle of incidence of less than 45°, the illuminance on the surfaces 271q and 271s of the strand 271 is relatively high.

[0131] Furthermore, surface 271q is positioned at an angle to receive air in the main direction of the airflow AF of the ventilation passage 120. This angle means that the angle between the normal direction of surface 271q and the direction downstream of the filter in the main direction of the airflow AF is greater than 90° and less than 180°. In other words, a relatively wide surface 271q is oriented with respect to the main direction of the airflow AF. Therefore, air that hits surface 271q flows along surface 271q. Consequently, compared to, for example, the case where the cross section perpendicular to the longitudinal direction of the strand 271 is circular, the area over which delamination does not occur after air hits is wider. As a result, the air purification efficiency per unit area is increased on surfaces 271q and 271s of the substrate 27. Moreover, the effect is even greater if the angle between the normal direction of surface 271q and the direction downstream of the filter in the main direction of the airflow AF is greater than 135°.

[0132] Furthermore, as shown in Figure 25, in the upstream filter 24 and the downstream filter 25, the longitudinal direction L1 of some or all of the mesh of the substrate 27 is arranged to be parallel to the transverse direction. Therefore, compared to the case where the longitudinal direction L1 is parallel to the front-to-back direction, the angle of incidence of light on the surfaces 271q and 271s of the strand 271 becomes relatively small. As a result, the illuminance on the strand 271 becomes relatively high. Consequently, the air purification efficiency per unit area of ​​the substrate 27 is increased.

[0133] The air purification device of the eighth embodiment described above also provides the same effects as the first embodiment. In addition, the air purification device of the eighth embodiment can also provide the following effects.

[0134] (1) In the eighth embodiment, the air purification device includes an intermediate filter 50 positioned in the main direction of the light emitted from the light-emitting unit 300, which receives the light emitted from the light-emitting unit 300 and allows air to pass through. The intermediate filter 50 has a photocatalyst 26 (i.e., an intermediate photocatalyst) that is activated by receiving the light emitted from the light-emitting unit 300 and purifies the air passing through the intermediate filter 50, and a substrate 27 (i.e., an intermediate substrate) on which the photocatalyst 26 is arranged. The substrate 27 is a mesh-shaped member. According to this, the light emitted from the light-emitting unit 300 between the upstream filter 24 and the downstream filter 25 can be effectively utilized by the photocatalyst 26 of the intermediate filter 50. Furthermore, by determining the number of peaks according to the aperture ratio of the mesh shape of the intermediate filter 50, the light can be fully utilized in the central region in the front-to-back direction of the photocatalyst module 23. In addition, by setting the intermediate filter 50 to an appropriate number of peaks, the ventilation area is increased and the ventilation resistance is reduced, resulting in these effects.

[0135] (2) In the eighth embodiment, the intermediate filter 50 has one or more portions in which the plate surface is positioned diagonally with respect to the principal direction of light emitted from the light-emitting portion 300. The plate surface of the intermediate filter 50 refers to the surface that faces the thickness direction of the plate material when the intermediate filter 50 is assumed to be a plate material with extremely small mesh (i.e., a virtual plane). According to this, the portion of the intermediate filter 50 where the plate surface is positioned at an angle is more easily illuminated by light emitted from the light-emitting section 300, and also more easily illuminated by the airflow from the upstream to the downstream side through the air passage 120. Therefore, since the airflow hits the portion of the intermediate filter 50 where the photocatalytic reaction is occurring, the air purification effect can be enhanced. Furthermore, by appropriately setting the number of sections where the plate surface of the intermediate filter 50 is arranged diagonally, that is, the number of peaks in the intermediate filter 50, the ventilation area is increased, resulting in the effect of reducing ventilation resistance.

[0136] (3) In the eighth embodiment, the light-emitting unit 300 and the intermediate filter 50 are arranged at a predetermined distance apart, with the upstream filter 24 positioned upstream of the main direction of the airflow AF between the light-emitting unit 300 and the intermediate filter 50, and the downstream filter 25 positioned downstream. According to this, if the intermediate filter 50 is placed adjacent to the light-emitting unit 300, light will be strongly irradiated onto the intermediate filter 50 near the light-emitting unit 300, preventing light from reaching the central region in the front-to-back direction of the photocatalytic module 23. In contrast, by arranging the light-emitting unit 300 and the intermediate filter 50 at a predetermined distance apart, light will reach the central region in the front-to-back direction of the photocatalytic module 23 where the intermediate filter 50 is located, and furthermore, light will be irradiated onto the upstream filter 24 and the downstream filter 25. Therefore, the air purification effect can be enhanced. Even if the light-emitting unit 300 and the intermediate filter 50 are separated by a predetermined distance (for example, about 5 mm), light will still be irradiated onto the upstream filter 24 and the downstream filter 25, thereby enhancing the air purification effect.

[0137] (4) In the eighth embodiment, the filter and the intermediate filter 50 are formed integrally. According to this, the number of parts and assembly steps for the photocatalytic module 23 will not increase, and manufacturing costs can be reduced.

[0138] (5) In the eighth embodiment, the light emitted from the light-emitting unit 300 is configured to be oriented more broadly in the horizontal direction than in the vertical direction. According to this, the light emitted from the light-emitting unit 300 is widely oriented in the lateral direction, allowing light to be broadly and uniformly irradiated onto the upstream filter 24, the downstream filter 25, and the intermediate filter 50. Therefore, the air purification efficiency can be improved. Furthermore, because the light emitted from the light-emitting section 300 is narrowly oriented in the vertical direction, light leakage from the upstream filter 24 and the downstream filter 25 can be reduced. Therefore, the loss of light energy can be minimized.

[0139] (6) In the eighth embodiment, the air purification device includes a cylindrical lens 40 positioned opposite the light-emitting unit 300. The cylindrical lens 40 has an arc-shaped surface with a predetermined imaginary line parallel to the lateral direction as its axis in a cross-sectional view perpendicular to the lateral direction. According to this, by passing the light emitted from the light-emitting unit 300 through the cylindrical lens 40, it becomes possible to orient the light more broadly in the horizontal direction than in the vertical direction. Therefore, it is possible to reduce light leakage from the upstream filter 24 and the downstream filter 25, and to broadly and uniformly irradiate the upstream filter 24, the downstream filter 25, and the intermediate filter 50 with light.

[0140] (Ninth Embodiment) Next, the ninth embodiment will be described using Figure 26. Figure 26 is an enlarged view of the one-side substrate 31, light-emitting section 300, and cylindrical lens 40 of the air purification device in the ninth embodiment. In the ninth embodiment as well, the multiple cylindrical lenses 40 are arranged in a horizontal line at positions corresponding to the multiple light-emitting sections 300. The multiple cylindrical lenses 40 are connected horizontally and formed as a single unit. The part that connects adjacent cylindrical lenses 40 will be called the connecting section 43. The connecting section 43 is also made of a light-transmitting material, just like the cylindrical lenses 40. The connecting section 43 and the cylindrical lenses 40 are continuously and integrally formed from the same material. A positioning projection 44 is provided on the surface of the connecting section 43 that faces the one-side substrate 31. On the other hand, a positioning hole 33 is provided on the one-side substrate 31. By fitting the positioning projection 44 of the connecting portion 43 into the positioning hole 33 of the one-side substrate 31, the positions of the multiple cylindrical lenses 40 relative to the one-side substrate 31 can be easily and reliably determined.

[0141] In the ninth embodiment described above, by connecting multiple cylindrical lenses 40 with connecting parts 43 to form a single unit, the number of parts in the air purification device can be reduced, and consequently, the assembly time can also be reduced.

[0142] (Tenth embodiment) Next, the tenth embodiment will be described using Figure 27. As shown in Figure 27, the tenth embodiment is a configuration in which the intermediate filter 50 is eliminated compared to the eighth embodiment. Note that the upstream filter 24 and the downstream filter 25 are not shown in Figure 27. This is also the case in Figures 28 to 31 and 34, which will be referenced in the eleventh to sixteenth embodiments described later. Also, in Figures 27 to 31, the direction in which light emitted from the light-emitting unit 300 via the cylindrical lens 40 or the light guide rod 341 travels is indicated by arrows.

[0143] As shown in Figure 27, in the tenth embodiment, the photocatalytic module 23 as an air purification device includes a light-emitting unit 300, a cylindrical lens 40, an upstream filter 24, a downstream filter 25, and the like. The light emitted from the light-emitting unit 300 is radiated via the cylindrical lens 40. Therefore, in the tenth embodiment as well, the light emitted from the light-emitting unit 300 via the cylindrical lens 40 is emitted in a narrow range in the vertical direction and spreads out in the horizontal direction. Consequently, in the tenth embodiment as well, the light emitted from the light-emitting unit 300 is oriented more broadly in the horizontal direction than in the vertical direction. As a result, the air purification device of the tenth embodiment can also improve the air purification efficiency by broadly and uniformly irradiating the upstream filter 24 and the downstream filter 25 with light. Furthermore, by reducing the leakage of light from the upstream filter 24 and the downstream filter 25, the loss of light energy can be reduced.

[0144] (Embodiments 11-13) The 11th to 13th embodiments are configurations in which the shape of the intermediate filter 50 is changed compared to the configuration of the 8th embodiment.

[0145] (11th embodiment) The 11th embodiment will be described with reference to Figure 28. As shown in Figure 28, the intermediate filter 50 of the air purification device of the 11th embodiment is arranged in two rows extending horizontally between the upstream filter 24 and the downstream filter 25. Although not shown in the figure, the intermediate filter 50 is arranged parallel to the vertical direction. Note that the number of rows of the intermediate filter 50 is not limited to that shown and can be set arbitrarily.

[0146] In the configuration of the 11th embodiment, the light emitted from the light-emitting unit 300 through the cylindrical lens 40 between the upstream filter 24 and the downstream filter 25 can be effectively utilized by the upstream filter 24, the downstream filter 25, and the intermediate filter 50.

[0147] (12th embodiment) Next, the twelfth embodiment will be described using Figure 29. As shown in Figure 29, the intermediate filter 50 of the air purification device of the twelfth embodiment has an M-shape (in other words, a mountain shape) with mountain folds and valley folds in the front-to-back direction. The intermediate filter 50 is also arranged in two rows between the upstream filter 24 and the downstream filter 25. Although not shown in the figure, the intermediate filter 50 is arranged parallel to the vertical direction. Note that the number of folds and the number of rows of the intermediate filter 50 are not limited to those shown and can be set arbitrarily.

[0148] In the configuration of the 12th embodiment, the light emitted from the light-emitting unit 300 through the cylindrical lens 40 between the upstream filter 24 and the downstream filter 25 can be effectively utilized by the upstream filter 24, the downstream filter 25, and the intermediate filter 50.

[0149] (13th Embodiment) Next, the 13th embodiment will be described using Figure 30. As shown in Figure 30, the intermediate filter 50 of the air purification device of the 13th embodiment is arranged in two rows between the upstream filter 24 and the downstream filter 25 and has a curved shape in the front-to-back direction. Specifically, the intermediate filter 50 arranged on the one-side substrate 31 has both ends in the lateral direction close to the one-side substrate 31 and is curved so that the central part is convex toward the center of the photocatalyst module 23. Similarly, the intermediate filter 50 arranged on the other-side substrate 32 has both ends in the lateral direction close to the other-side substrate 32 and is curved so that the central part is convex toward the center of the photocatalyst module 23. Although not shown in the figure, the intermediate filters 50 are arranged parallel to the vertical direction. Note that the curvature and number of rows of the intermediate filters 50 are not limited to those shown and can be set arbitrarily.

[0150] In the configuration of the 13th embodiment, the light emitted from the light-emitting unit 300 through the cylindrical lens 40 between the upstream filter 24 and the downstream filter 25 can be effectively utilized by the upstream filter 24, the downstream filter 25, and the intermediate filter 50.

[0151] (Embodiments 14-16) Embodiments 14 to 16 are configurations in which an intermediate filter 50 is added to the configuration of the first embodiment (i.e., the air purification device is equipped with a light guide rod 341).

[0152] (14th Embodiment) Next, the 14th embodiment will be described with reference to Figures 31 and 32. As shown in Figures 31 and 32, the air purification device of the 14th embodiment includes a plurality of light guide rods 341 as described in the first embodiment. The plurality of light guide rods 341 are arranged to extend in the front-rear direction between a corresponding one-side light-emitting unit 311 and a corresponding other-side light-emitting unit 321.

[0153] Light emitted from one side light-emitting section 311 enters the light guide rod 341 from the end of the light guide rod 341 on the side of the light guide rod 311, passes through the light guide rod 341, and is emitted laterally from the first prism section 341d and the second prism section 341f of the light guide rod 341. Light emitted from the other side light-emitting section 321 enters the light guide rod 341 from the end of the light guide rod 341 on the side of the light guide rod 321, passes through the light guide rod 341, and is emitted laterally from the first prism section 341d and the second prism section 341f of the light guide rod 341.

[0154] As shown in Figure 31, the multiple intermediate filters 50 are arranged parallel to the multiple light guide rods 341. Furthermore, some of the multiple intermediate filters 50 are positioned between the multiple light guide rods 341. The multiple intermediate filters 50 are arranged to extend in the front-to-back direction. As shown in Figure 32, the intermediate filters 50 are arranged parallel to the vertical direction. Note that the shape and number of rows of the intermediate filters 50 are not limited to those shown and can be arbitrarily set.

[0155] In the configuration of the 14th embodiment, the light emitted from the light-emitting unit 300 via the light guide rod 341 between the upstream filter 24 and the downstream filter 25 can be effectively utilized by the upstream filter 24, the downstream filter 25, and the intermediate filter 50.

[0156] (15th Embodiment) Next, the 15th embodiment will be described using Figure 33. Figure 33 is a cross-sectional view of the area corresponding to Figure 32 used in the description of the 14th embodiment. As shown in Figure 33, the multiple intermediate filters 50 provided in the air purification device of the 15th embodiment are formed in a V-shape (in other words, a mountain shape) in a cross-sectional view perpendicular to the front-to-back direction. Although not shown in the illustration, the multiple intermediate filters 50 of the 15th embodiment are also arranged to extend in the front-to-back direction parallel to the multiple light guide rods 341. Note that the shape and number of rows of the intermediate filters 50 are not limited to those shown and can be set arbitrarily.

[0157] In the configuration of the 15th embodiment, the light emitted from the light-emitting unit 300 via the light guide rod 341 between the upstream filter 24 and the downstream filter 25 can be effectively utilized by the upstream filter 24, the downstream filter 25, and the intermediate filter 50.

[0158] (16th Embodiment) Next, the 16th embodiment will be described using Figure 34. As shown in Figure 34, the intermediate filter 50 of the air purification device of the 16th embodiment is arranged alongside a plurality of light guide rods 341. In addition, a part of the intermediate filter 50 is arranged between the plurality of light guide rods 341. Furthermore, this intermediate filter 50 has an M-shape (in other words, a mountain shape) with mountain folds and valley folds in the horizontal direction. Although not shown in the figure, the intermediate filter 50 is arranged parallel to the vertical direction. Note that the number of folds and the number of rows of the intermediate filter 50 are not limited to those shown in the figure and can be set arbitrarily.

[0159] In the configuration of the 16th embodiment, the light emitted from the light-emitting unit 300 via the light guide rod 341 between the upstream filter 24 and the downstream filter 25 can be effectively utilized by the upstream filter 24, the downstream filter 25, and the intermediate filter 50.

[0160] (17th Embodiment) Next, the 17th embodiment will be described using Figure 35. Figure 35 is a diagram of the area corresponding to Figure 24 used in the description of the 8th embodiment. In the 17th embodiment, the method of arranging the mesh of the art metal with respect to the light-emitting section 300 will be described. In Figure 35, a virtual plane VS1 equidistant from the upstream filter 24 and the downstream filter 25 is shown by a dashed line. The main direction of the light emitted from one side light-emitting section 311 via the cylindrical lens 40 is along the virtual plane VS1. However, some of the light emitted from the light-emitting section 300 is emitted at a steep, acute angle with respect to the virtual plane VS1.

[0161] In the upstream filter 24 and the downstream filter 25, the arrangement of the mesh of the art metal allows light emitted from the light-emitting section 300 to leak out of the photocatalytic module 23 more easily (hereinafter referred to as the reverse side) and less easily (hereinafter referred to as the forward side).

[0162] In the 17th embodiment, both the upstream filter 24 and the downstream filter 25 are positioned so that the mesh of the art metal faces the one-side light-emitting section 311. More specifically, facing the one-side light-emitting section 311 means that the surfaces of the art metal strands 271 and bonds 272 that face the one-side light-emitting section 311 are inclined toward the virtual plane VS1 with respect to the vertical direction. As a result, the angle between the light rays emitted from the light-emitting section 300 via the cylindrical lens 40 and the normals of the surfaces of the strands 271 and bonds 272 of the upstream filter 24 and the downstream filter 25 that face the one-side light-emitting section 311 becomes smaller. Also, when viewing the upstream filter 24 and the downstream filter 25 from the one-side light-emitting section 311, the mesh space appears smaller. Therefore, light is less likely to leak out of the upstream filter 24 and the downstream filter 25.

[0163] In Figure 35, two arrows indicate a portion of the light rays emitted from the one-side light-emitting unit 311 via the cylindrical lens 40, specifically a portion of the rays emitted towards the upstream filter 24 and a portion of the rays emitted towards the downstream filter 25. The angles θ1 and θ2 between the rays indicated by these two arrows and the virtual plane are assumed to be the same. Both the upstream filter 24 and the downstream filter 25 are positioned so that the mesh of the art metal faces forward relative to the one-side light-emitting unit 311, thus preventing light from leaking out of the photocatalytic module 23. Therefore, the air purification device of the 17th embodiment can reduce the energy loss of light emitted from the one-side light-emitting unit 311 and further improve the air purification efficiency of each filter.

[0164] (18th embodiment) Next, the 18th embodiment will be described using Figure 36. Figure 36 is a diagram showing a wide range of the air purification device, including the parts corresponding to Figure 35 used in the description of the 17th embodiment. In Figure 36, the first virtual plane VS1, which is equidistant from the upstream filter 24 and the downstream filter 25, is shown by a dashed line, and the second virtual plane VS2, which is equidistant from the one-side light-emitting unit 311 and the other-side light-emitting unit 321, is shown by a double-dashed line.

[0165] As shown in Figure 36, in the eighth embodiment, the upstream filter 24 and downstream filter 25, which are located in the region on the side of the one-side light-emitting section 311 relative to the second virtual plane VS2, are positioned so that the mesh of the art metal faces the one-side light-emitting section 311. The "forward direction" relative to the one-side light-emitting section 311 means that the faces of the strands 271 and bonds 272 of the art metal that face the one-side light-emitting section 311 are tilted toward the first virtual plane VS1 with respect to the vertical direction. As a result, light emitted from the one-side light-emitting section 311 is less likely to leak out of the upstream filter 24 and downstream filter 25.

[0166] Furthermore, in the 18th embodiment, the upstream filter 24 and downstream filter 25, which are located in the region on the other side of the light-emitting section 321 relative to the second virtual surface VS2, are also positioned so that the mesh of the art metal faces the other side of the light-emitting section 321. "Facing the other side of the light-emitting section 321" means that the faces of the art metal strands 271 and bonds 272 that face the other side of the light-emitting section 321 are tilted toward the first virtual surface VS1 with respect to the vertical direction. This makes it difficult for light emitted from the other side of the light-emitting section 321 to leak out of the upstream filter 24 and downstream filter 25. Therefore, the air purification device of the 18th embodiment can reduce the energy loss of light emitted from the one-side light-emitting section 311 and the other-side light-emitting section 321, and further improve the air purification efficiency of each filter.

[0167] (Other embodiments) Furthermore, the present invention is not limited to the embodiments described above and can be modified as appropriate. Also, the embodiments described above are not unrelated to each other and can be combined as appropriate, except in cases where combination is clearly impossible. In addition, the elements constituting the embodiments in the embodiments are not necessarily essential, except in cases where they are explicitly stated to be particularly essential or where they are clearly considered essential in principle. Furthermore, in the embodiments described above, when numerical values ​​such as the number, values, quantities, or ranges of the constituent elements of the embodiments are mentioned, the embodiments are not limited to those specific numbers, except in cases where they are explicitly stated to be particularly essential or where they are clearly limited to a specific number in principle. In particular, when multiple values ​​are given as examples for a certain quantity, it is possible to adopt a value between those multiple values, except in cases where they are specifically noted separately or where they are clearly impossible in principle. Furthermore, when the shapes, positional relationships, etc., of constituent elements, etc., are mentioned in the embodiments described above, the embodiments are not limited to those shapes, positional relationships, etc., except in cases where they are explicitly stated or where they are clearly limited to a specific shape, positional relationship, etc., in principle. The present invention also permits the following modifications of the embodiments and modifications of the equivalent range. Note that the following modifications can be independently applied to or not applied to the embodiments described above. In other words, any combination of the following modified examples can be applied to the above embodiment.

[0168] (Variation 1) In each of the above embodiments, the light emitted from the light-emitting unit 300 is light containing ultraviolet light, but the light emitted from the light source device 30 may be light that does not contain ultraviolet light. For example, the light emitted from the light-emitting unit 300 may be visible light. In that case, a visible light-responsive photocatalyst 26 is used.

[0169] (Modification 2) In each of the above embodiments, a light guide rod 341 is exemplified as a light guide that biases the directionality of the light emitted from the light-emitting unit 300. However, the light guide is not limited to a rod shape. For example, a lens that is not rod-shaped may be used as the light guide.

[0170] (Variation 3) In each of the above embodiments, an example is shown in which a base material 27 having a square mesh is formed by connecting four strands 271 to one bond 272. However, a base material 27 having a hexagonal mesh may be formed by connecting three strands 271 to one bond 272. Alternatively, a base material 27 having various meshes such as triangles may be formed by connecting five or more strands 271 to one bond 272.

[0171] (Modification 4) In each of the above embodiments, the longitudinal direction of the mesh of the substrate 27 intersects at 90° with the direction in which the principal direction of light emitted from the light guide rod 341 is projected onto the surface of the substrate 27 in the upstream filter 24, the downstream filter 25, and the intermediate filter 50. However, the angle of intersection is not limited to 90°; if the mesh intersects rather than is parallel, the air purification efficiency per unit area of ​​the substrate 27 will be higher compared to the case where the mesh is parallel.

[0172] (Variation 5) In each of the above embodiments, the base material 27 of the upstream filter 24, downstream filter 25, additional filter 28, and intermediate filter 50 is art metal, but the base material 27 is not limited to art metal. The base material 27 may be expanded metal. Alternatively, the base material 27 may be a wire mesh in which multiple wires are woven together vertically and horizontally. Furthermore, the base material 27 may or may not be made of metal. For example, the base material 27 may be made of resin. Also, on the surface of the base material 27, the ratio of the area occupied by the mesh, which is the gap, within the outer shape of the base material 27 to the total area on the surface of the base material 27 within the outer shape of the base material 27 may be less than 50%. For example, the base material 27 may be a mesh-shaped nonwoven fabric.

[0173] (Experimental variation 6) In each of the above embodiments, the strand 271 of the base material 27 is a member with a rectangular cross-section having four sides and four faces. However, the strand 271 may also be a member with a triangular cross-section having three sides and three faces, or a member with five or more sides and five or more faces. Furthermore, the base material 27 may also be a member with a semicircular cross-section having two sides, one plane, and one cylindrical curved surface.

[0174] (Example 7) In the above embodiment, the mesh of the base material 27 constituting the additional filter 28 and the mesh of the base material 27 constituting the upstream filter 24 and the downstream filter 25 have different orientations. However, the differences between the mesh of the base material 27 constituting the additional filter 28 and the mesh of the base material 27 constituting the upstream filter 24 and the downstream filter 25 are not limited to orientation. For example, they may be different in size or shape.

[0175] (Variation 8) In each of the above embodiments, the mesh of the base material 27 constituting the upstream filter 24 and the mesh of the base material 27 constituting the downstream filter 25 may be the same or different.

[0176] (Extreme variation 9) In each of the embodiments described above, the additional filter 28 is located on the downstream side of the light source device 30, on the side of the filter 25. However, the additional filter 28 may also be located on the upstream side of the light source device 30, on the side of the filter 24. In this case, the downstream filter 25 corresponds to the first filter, and the additional filter 28 corresponds to the second filter.

[0177] (Variation 10) In each of the embodiments described above, an example is shown in which the photocatalyst 26 is supported on the substrate 27. However, the form in which the photocatalyst 26 is supported on the substrate 27 is not limited to this.

[0178] (Variation 11) In each of the embodiments described above, the photocatalytic module 23 is shown to include an upstream filter 24 and a downstream filter 25, etc. However, the photocatalytic module 23 may include only the upstream filter 24, or only the downstream filter 25.

[0179] (Example 12) In each of the above embodiments, an example is shown in which the light-emitting unit 300 has one side light-emitting unit 311 and the other side light-emitting unit 321. However, the light-emitting unit may consist of only the one side light-emitting unit 311, or only the other side light-emitting unit 321.

[0180] (Example 13) In each of the above embodiments, an example is shown in which the cylindrical lens 40 has one cylindrical lens 41 and the other cylindrical lens 42. However, the light-emitting part may consist only of the one cylindrical lens 41, or only of the other cylindrical lens 42.

[0181] The air purification devices of each embodiment described above are intended for use in vehicles. However, air purification devices can also be used in homes and for stationary commercial use. [Explanation of symbols]

[0182] 24 Upstream filter 25 Downstream filter 26 Photocatalyst 27 Base material 120 Ventilation duct 300 Light-emitting part 311 One-sided light-emitting section 321 Other side light-emitting section

Claims

1. In an air purification device that purifies the air flowing through a ventilation passage (120), A light-emitting unit (300) having a one-side light-emitting unit (311) and a other-side light-emitting unit (321) arranged opposite each other such that the main direction of light emitted from one-side light-emitting unit and the main direction of light emitted from the other-side light-emitting unit face each other, A first filter (24) is positioned upstream of the main direction of the airflow (AF) that intersects the main direction of the light emitted from the light-emitting part within the ventilation passage, and receives the light emitted from the light-emitting part and allows air to pass through, the first filter having a first photocatalyst (26) that is activated by receiving the light emitted from the light-emitting part and purifies the air passing through the filter, and a first substrate (27) which is a mesh-shaped member on which the first photocatalyst is arranged, A second filter (25) is positioned in the ventilation passage opposite the first filter on the downstream side of the main direction of the airflow that intersects the main direction of the light emitted from the light-emitting part, and receives the light emitted from the light-emitting part and allows air to pass through, the second filter having a second photocatalyst (26) that is activated by receiving the light emitted from the light-emitting part and purifies the air passing through the second filter, and a second substrate (27) which is a mesh-shaped member on which the second photocatalyst is arranged, The intermediate filter (50) is positioned in the main direction of the light emitted from the light-emitting part and receives the light emitted from the light-emitting part while allowing air to pass through, and comprises an intermediate photocatalyst (26) that is activated by receiving the light emitted from the light-emitting part and purifies the air passing through the intermediate filter, and an intermediate substrate (27) which is a mesh-shaped member on which the intermediate photocatalyst is arranged. The aforementioned intermediate filter has one or more locations where the plate surface is positioned diagonally with respect to the principal direction of light emitted from the light-emitting section. The aforementioned one-side light-emitting section and the intermediate filter are arranged at a predetermined distance apart. The other side light-emitting unit and the intermediate filter are arranged at a predetermined distance apart. An air purification device in which the first filter and the second filter are arranged between the light-emitting unit and the intermediate filter, respectively, on the upstream and downstream sides of the main direction of airflow.

2. The air purification device according to claim 1, wherein a part of the first filter is bent toward the second filter so that the first filter and the intermediate filter are integrally formed, or a part of the second filter is bent toward the first filter so that the second filter and the intermediate filter are integrally formed.

3. The first substrate has a plurality of strands (271) extending in a striated manner, and a plurality of bonds (272) to which three or more of the plurality of strands are connected, and a mesh shape is formed by the plurality of strands and the plurality of bonds. At least some of the strands have at least two sides (271a, 271b, 271c, 271d) and faces (271q, 271s) connecting the two sides. The air purification device according to claim 1 or 2, wherein at least a portion of the aforementioned surface is arranged on the photocatalyst and is oriented toward the light emitted from the light-emitting part.

4. The main direction of airflow in the aforementioned ventilation passage is called the longitudinal direction. When the direction perpendicular to the vertical direction and perpendicular to the main direction of light emitted from the light-emitting part is called the horizontal direction, The air purification device according to any one of claims 1 to 3, wherein the light emitted from the light-emitting part is configured to be oriented more broadly in the horizontal direction than in the vertical direction.

5. The light-emitting portion is equipped with cylindrical lenses (40, 41, 42) positioned opposite to it, The air purification device according to claim 4, wherein the cylindrical lens has arc-shaped surfaces (401, 402) with a predetermined imaginary line parallel to the lateral direction as its axis in a cross-sectional view perpendicular to the lateral direction.

6. The light-emitting units are arranged in a row in the horizontal direction. The air purification device according to claim 5, wherein the plurality of cylindrical lenses, which are arranged opposite to the plurality of light-emitting portions, are connected in the lateral direction and formed integrally.

7. The air purification device according to claim 3, wherein at least a portion of the aforementioned surface is oriented toward the light emitted from the light-emitting part on which the photocatalyst is arranged, and is arranged at an inclination to receive air in the main direction of the airflow of the ventilation passage.

8. The air purification device according to any one of claims 1 to 7, wherein the first substrate is arranged such that the longitudinal direction (L1) of the plurality of meshes intersects with the direction (DL) obtained by projecting the principal direction of light emitted from the light-emitting part to the first filter onto the plate surface of the first substrate.

9. The air purification device according to any one of claims 1 to 8, further comprising a light guide rod (341) that guides the light emitted by the light-emitting part to suppress variations in the illuminance distribution on the first substrate.

10. The air purification device according to any one of claims 1 to 9, further comprising a third filter (28) which is a mesh-shaped member arranged in overlap with the first filter or the second filter.

11. The air purification device according to claim 10, wherein the mesh of the first substrate or the second substrate of the first filter or the second filter is located at a position where it is separated from the mesh of the third filter.

12. The distance (L) between the portion of the intermediate filter whose plate surface is positioned diagonally with respect to the principal direction of light emitted from the one-side light-emitting portion and the one-side light-emitting portion is between 23% and 37% of the distance (LOA) between the one-side light-emitting portion and the other-side light-emitting portion. The air purification device according to any one of claims 1 to 11, wherein the distance (L) between the portion of the intermediate filter whose plate surface is positioned diagonally with respect to the main direction of light emitted from the other side light-emitting portion and the other side light-emitting portion is between 23% and 37% of the distance (LOA) between the one side light-emitting portion and the other side light-emitting portion.

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