Ultraviolet irradiation device and air conditioner

Abstract

An ultraviolet irradiation device (60) is provided with: an irradiation part (61) disposed on one end side in a first direction of a processing space (R); and a first reflective part (70) disposed on the other end side in the first direction of the processing space (R). The irradiation part (61) has: a surface light source (62) having a light-emitting surface (65); and a lens (67) and a reflector (68) as optical components (OP) for directing ultraviolet light emitted from the surface light source (62) onto the first reflective part (70). The lens (67) and the reflector (68) generate a paraxial image surface (90) of the light-emitting surface (65) on an irradiated surface (71a) irradiated with the ultraviolet light, the irradiated surface (71a) being a part of the first reflective part (70).

Description

Ultraviolet irradiation device and air conditioner

[0001] The present disclosure relates to an ultraviolet irradiation device and an air conditioner.

[0002] Patent Document 1 discloses an ultraviolet irradiation device for use in an air conditioner. This ultraviolet irradiation device is disposed within the housing of the indoor unit and irradiates ultraviolet rays toward the ventilation passage within the housing. The ultraviolet irradiation device includes an ultraviolet light-emitting diode that irradiates ultraviolet rays and a reflecting member that reflects the ultraviolet rays irradiated from the ultraviolet light-emitting diode.

[0003] The ultraviolet light emitting diode and the reflecting member are positioned so that the air flowing through the ventilation duct passes between them. The ultraviolet light emitted from the ultraviolet light emitting diode is converted into parallel light and then irradiated onto the reflecting member. The ultraviolet light reflected by the reflecting member is sent toward the ultraviolet light emitting diode along the optical axis of the parallel light. In this way, the ultraviolet light traveling back and forth between the ultraviolet light emitting diode and the reflecting member is irradiated onto the air flowing through the ventilation duct, thereby inactivating viruses and bacteria in the air.

[0004] Japanese Patent Application Laid-Open No. 2022-126495

[0005] In an ultraviolet irradiation device such as that disclosed in Patent Document 1, a surface light source having a light-emitting surface is used as an ultraviolet light-emitting diode. It is difficult to convert the ultraviolet light emitted from the surface light source into perfectly parallel light, even when a lens or reflector is combined. When the ultraviolet light emitted from the ultraviolet light-emitting diode spreads in the direction of travel, the ultraviolet light spreads further when reflected by the first reflecting portion. As a result, ultraviolet light cannot be efficiently irradiated onto the air flowing through a treatment space such as an air duct.

[0006] An object of the present disclosure is to efficiently irradiate ultraviolet rays onto air flowing through a processing space.

[0007] A first aspect of the present disclosure relates to an ultraviolet irradiation device (60) that irradiates ultraviolet rays into a processing space (R) through which air flows. The ultraviolet irradiation device (60) of the first aspect includes an irradiation unit (61) disposed at one end of the processing space (R) in a first direction and irradiating ultraviolet rays toward the other end in the first direction, and a first reflector (70) disposed at the other end of the processing space (R) in the first direction and reflecting the ultraviolet rays irradiated from the irradiation unit (61) toward the one end in the first direction. The irradiation unit (61) includes a surface light source (62) having a light-emitting surface (65) that emits ultraviolet rays, and an optical component (OP) that collects the ultraviolet rays emitted from the surface light source (62) toward the first reflector (70). The optical component (OP) is configured to generate a paraxial image plane (90) of the light-emitting surface (65) on an irradiated surface (71a) onto which ultraviolet rays from the first reflector (70) are irradiated.

[0008] In this first aspect, the irradiation unit (61) is disposed at one end of the treatment space (R), and the first reflection unit (70) is disposed at the other end of the treatment space (R). The irradiation unit (61) collects ultraviolet light emitted from the surface light source (62) toward the first reflection unit (70) using an optical component (OP). The optical component (OP) generates a paraxial image plane (90) of the light-emitting surface (65) on the irradiation surface (71a) onto which the ultraviolet light of the first reflection unit (70) is irradiated. This prevents the ultraviolet light reflected by the irradiation surface (71a) of the first reflection unit (70) from spreading in the direction of travel. This allows the ultraviolet light to be efficiently irradiated onto the air flowing through the treatment space (R).

[0009] A second aspect of the present disclosure is the ultraviolet irradiation device (60) of the first aspect, wherein the irradiation unit (61) has, as the optical component (OP), a lens that refracts ultraviolet light emitted from the surface light source (62). The ultraviolet light emitted from the surface light source (62) has a wavelength of 200 nm or more and 300 nm or less.

[0010] In this second aspect, the ultraviolet light emitted from the surface light source (62) has a relatively short wavelength of 200 nm or more and 300 nm or less. The shorter the wavelength of the ultraviolet light, the more easily it is refracted by the lens (67). Therefore, by using the lens (67), it is easy to adjust the ultraviolet light emitted from the surface light source (62) so that a paraxial image plane (90) of the light-emitting surface (65) is generated on the irradiated surface (71a) of the first reflecting portion (70). Furthermore, the ultraviolet light with the above-mentioned relatively short wavelength is suitable for inactivating viruses and bacteria in the air.

[0011] A third aspect of the present disclosure is the ultraviolet irradiation device (60) of the first or second aspect, wherein the width of the paraxial image plane (90) in a predetermined direction is 20 mm or more and 70 mm or less.

[0012] In this third aspect, the width of the paraxial image plane (90) in a predetermined direction is 20 nm or more and 70 mm or less. When a paraxial image plane (90) of such dimensions is generated on the irradiated surface (71a), the ultraviolet irradiation device (60) can be configured relatively compactly. This allows the ultraviolet irradiation device (60) to be installed even in a limited space inside an existing device such as an air conditioner (10).

[0013] A fourth aspect of the present disclosure is the ultraviolet irradiation device (60) of the third aspect, wherein the irradiation unit (61) has, as the optical component (OP), a lens (67) that refracts ultraviolet light emitted from the surface light source (62). The lens (67) is disposed on the front side of the light-emitting surface (65). When an irradiation distance, which is the distance between the light-emitting surface (65) of the surface light source (62) and the irradiated surface (71 a) of the first reflecting unit (70) is Li [mm] and a maximum width of the light-emitting surface (65) in a predetermined direction is Wl [mm], a distance La [mm] between a principal point (P1) of the lens (67) and the light-emitting surface (65) satisfies the relationship Li × Wl / (70 + Wl) ≦ La ≦ Li × Wl / (20 + Wl).

[0014] In the fourth aspect, the distance La between the principal point P1 of the lens 67 and the light-emitting surface 65 is equal to or greater than Li×Wl / (70+Wl) and equal to or less than Li×Wl / (20+Wl). This allows a paraxial image plane 90 having a width in a predetermined direction of 20 nm to 70 mm to be generated on the irradiated surface 71 a of the first reflecting portion 70.

[0015] A fifth aspect of the present disclosure is the ultraviolet irradiation device (60) of the third or fourth aspect, wherein the irradiation unit (61) has, as the optical component (OP), a reflector (68) that reflects ultraviolet light emitted from the surface light source (62). The reflector (68) is disposed so as to surround a space in front of the light-emitting surface (65). A reflective surface (68a) of the reflector (68) that reflects ultraviolet light presents a curved surface that approximates a parabolic curved surface. When an irradiation distance, which is the distance between the light-emitting surface (65) of the surface light source (62) and the irradiated surface (71a) of the first reflecting portion (70), is Li [mm] and a maximum width of the light-emitting surface (65) in a predetermined direction is Wl [mm], a distance Lb [mm] between the vertex (P2) of a parabolic curved surface approximating the reflecting surface (68a) and the light-emitting surface (65) satisfies the relationship Li×Wl / (70−Wl)≦Lb≦Li×Wl / (20−Wl).

[0016] In the fifth aspect, the distance Lb between the vertex (P2) of the parabolic surface approximating the reflecting surface (68a) and the light-emitting surface (65) is equal to or greater than Li×Wl / (70−Wl) and equal to or less than Li×Wl / (20−Wl). This allows a paraxial image plane (90) having a width in a predetermined direction of 20 nm to 70 mm to be generated on the illuminated surface (71a) of the first reflecting section (70).

[0017] A sixth aspect of the present disclosure is the ultraviolet irradiation device (60) of any one of the third to fifth aspects, wherein the irradiation unit (61) has, as the optical component (OP), a lens (67) that refracts ultraviolet light emitted from the surface light source (62) and a reflector (68) that reflects the ultraviolet light emitted from the surface light source (62). The lens (67) is disposed on the front side of the light-emitting surface (65). The reflector (68) is disposed so as to surround the space on the front side of the light-emitting surface (65) and the lens (67). When an irradiation distance, which is the distance between the light-emitting surface (65) of the surface light source (62) and the irradiated surface (71 a) of the first reflecting portion (70), is Li [mm] and a maximum width of the light-emitting surface (65) in a predetermined direction is Wl [mm], an angle θ [°] that is a light distribution boundary between the lens (67) and the reflector (68) at a position on the optical axis (A0) of the lens (67) on the light-emitting surface (65) satisfies the relationship θ≦arctan (35×(70−Wl) / Li×Wl) (where θ≦89).

[0018] In the sixth aspect, assuming that the angle θ, which is the boundary of light distribution between the lens (67) and the reflector (68) at a position on the optical axis (A0) of the lens (67) on the light-emitting surface (65), is 89° or less, the angle θ is equal to or less than arctan (35×(70−Wl) / Li×Wl). This allows the diameter of the lens (67) to be equal to or less than 70 mm, which is the maximum size of the paraxial image plane (90) in a predetermined direction. Therefore, using a lens (67) with a relatively small diameter, a paraxial image plane (90) with a width in a predetermined direction of 20 nm or more and 70 mm or less can be generated on the irradiated surface (71a) of the first reflecting unit (70). This is advantageous for realizing a compact ultraviolet irradiation device (60).

[0019] A seventh aspect of the present disclosure is the ultraviolet irradiation device (60) according to any one of the first to sixth aspects, wherein the irradiated surface (71 a) is configured as a concave surface having a predetermined curvature. When an irradiation distance, which is the distance between the light emitting surface (65) of the surface light source (62) and the irradiated surface (71 a) of the first reflecting section (70), is Li [mm], the radius of curvature R1 of the irradiated surface (71 a) satisfies the relationship 0.5 × Li ≦ R1 ≦ 2 × Li.

[0020] In the seventh aspect, the radius of curvature R1 of the irradiated surface (71a) of the first reflecting portion (70) is greater than 0.5 times the irradiation distance Li and is equal to or less than twice the irradiation distance Li. The irradiated surface (71a) having such a radius of curvature R1 can reflect the ultraviolet light irradiated from the irradiating portion (61) toward the vicinity of the irradiating portion (61). This allows the ultraviolet irradiation device (60) to have a compact configuration and to be used even in a relatively narrow treatment space (R).

[0021] An eighth aspect of the present disclosure is an ultraviolet irradiation device (60) according to any one of the first to seventh aspects, further comprising a second reflecting section (80) that is arranged at one end side in the first direction of the treatment space (R) and reflects ultraviolet light reflected by the first reflecting section (70) toward the other end side in the first direction.

[0022] In the eighth aspect, the second reflecting section is disposed at one end of the treatment space (R) in the first direction, i.e., on the same side as the irradiating section (61). The ultraviolet light reflected by the first reflecting section (70) is reflected again by the second reflecting section (80) toward the other end in the first direction. This allows the ultraviolet light emitted from the irradiating section (61) to be repeatedly reflected between the first reflecting section (70) and the second reflecting section (80) and to remain in the treatment space (R) for a relatively long time. This is advantageous for efficiently irradiating the ultraviolet light to the air flowing through the treatment space (R).

[0023] A ninth aspect of the present disclosure is the ultraviolet irradiation device (60) of any one of the first to eighth aspects, wherein the irradiation unit (61) has, as the optical component (OP), a lens (67) that refracts ultraviolet light emitted from the surface light source (62). The lens (67) is a biconvex lens having a first surface (67a) located on the surface light source (62) side and a second surface (67b) located on the first reflecting unit (70) side, and the first surface (67a) and the second surface (67b) are both convex. The radius of curvature of the first surface (67a) is larger than the radius of curvature of the second surface (67b).

[0024] In this ninth aspect, the radius of curvature of the first surface (67a) of the lens (67) located on the surface light source (62) side is larger than the radius of curvature of the second surface (67b) located on the first reflecting portion (70) side. If the radius of curvature of the first surface (67a) is smaller than the radius of curvature of the second surface (67b), the distance between the principal point (P1) of the lens (67) and the surface light source (62) becomes shorter, and the magnification of the paraxial image plane (90) becomes larger. Therefore, this is not suitable for generating a paraxial image plane (90) of a size that fits within the illuminated surface (71a) of the first reflecting portion (70). In contrast, if the radius of curvature of the first surface (67a) is larger than the radius of curvature of the second surface (67b), the distance between the principal point (P1) of the lens (67) and the surface light source (62) becomes longer, and the magnification of the paraxial image plane (90) becomes smaller. This prevents the ultraviolet light emitted from the irradiating part (61) from leaking from the first reflecting part (70), and allows the ultraviolet light irradiating device (60) to be configured compactly.

[0025] A tenth aspect of the present disclosure is the ultraviolet irradiation device (60) of the ninth aspect, wherein the first surface (67a) and the second surface (67b) are each an even-order aspherical surface.

[0026] In the tenth aspect, the first surface (67a) and the second surface (67b) of the lens (67) are each an even-order aspheric surface. This reduces the aberration contained in the paraxial image plane (90). This is advantageous in preventing the ultraviolet light reflected by the irradiated surface (71a) of the first reflecting portion (70) from spreading in the direction of travel.

[0027] An eleventh aspect of the present disclosure is directed to an air conditioner (10). The air conditioner (10) of the eleventh aspect includes a casing (31) having an inlet (32) for drawing in air, an outlet (33) for blowing out air, and an air flow path (34) extending from the inlet (32) to the outlet (33), and an ultraviolet irradiation device (60) that uses a part of the air flow path (34) as a treatment space (R) and irradiates the treatment space (R) with ultraviolet light. The ultraviolet irradiation device (60) is the ultraviolet irradiation device (60) of any one of the first to tenth aspects.

[0028] In this eleventh aspect, the ultraviolet irradiation device (60) according to any one of the first to tenth aspects is used. The ultraviolet irradiation device (60) can efficiently irradiate the air flowing through the treatment space (R) with ultraviolet rays. Therefore, in the air conditioner (10), it becomes possible to effectively inactivate viruses and bacteria in the air by ultraviolet rays.

[0029] FIG. 1 is a piping diagram of an air conditioner according to an embodiment. FIG. 2 is a front view showing the exterior of an indoor unit. FIG. 3 is a cross-sectional view of the indoor unit taken along line A-A in FIG. 2. FIG. 4 is a view of the indoor heat exchanger as seen from the outlet side. FIG. 5 is a schematic diagram of the irradiation unit. FIG. 6 is a schematic diagram of the surface light source. FIG. 7 is a graph showing changes in refractive index for the same material depending on the wavelength range of light. FIG. 8 is a perspective view illustrating an example of the configuration of an optical system for generating a paraxial image plane of the light-emitting surface of the irradiation unit on the irradiated surface of the first reflecting unit. FIG. 9 is a diagram illustrating the distribution of ultraviolet irradiation intensity at the paraxial image plane generated on the irradiated surface of the first reflecting unit. FIG. 10 is a schematic diagram showing the main components of an ultraviolet irradiation device. FIG. 11 is a diagram corresponding to FIG. 4, in which arrows indicate the direction of travel of ultraviolet light in the ultraviolet irradiation device. FIG. 12 is a diagram corresponding to FIG. 3 of a modified air conditioner.

[0030] Exemplary embodiments will be described in detail below with reference to the drawings. In the following embodiments, an example will be given in which the ultraviolet irradiation device of the present disclosure is applied to an air conditioner. Note that the drawings are intended to conceptually explain the technology of the present disclosure. Therefore, in the drawings, dimensions, ratios, or numbers may be exaggerated or simplified to facilitate understanding of the technology of the present disclosure.

[0031] (1) Overview of the Air Conditioner The ultraviolet irradiation device (60) is applied to an air conditioner (10). The air conditioner (10) conditions the air in an indoor space (SI), which is a target space. The air conditioner (10) adjusts the temperature of the indoor air.

[0032] As shown in Fig. 1, the air conditioner (10) is a pair-type air conditioner and includes an outdoor unit (20) and an indoor unit (30). The outdoor unit (20) is installed outdoors. The indoor unit (30) is installed indoors. The outdoor unit (20) and the indoor unit (30) are connected to each other via a first connecting pipe (12) and a second connecting pipe (13).

[0033] The outdoor unit (20), the indoor unit (30), the first connecting pipe (12), and the second connecting pipe (13) constitute a refrigerant circuit (11). The refrigerant circuit (11) is filled with refrigerant. The refrigerant circuit (11) mainly includes a compressor (21), an outdoor heat exchanger (22), an expansion valve (23), a four-way switching valve (24), and an indoor heat exchanger (50). The compressor (21), the outdoor heat exchanger (22), the expansion valve (23), the four-way switching valve (24), and the indoor heat exchanger (50) are connected in series by piping.

[0034] The compressor (21), the outdoor heat exchanger (22), the expansion valve (23), and the four-way selector valve (24) are included in the outdoor unit (20). The outdoor unit (20) further includes an outdoor fan (25).

[0035] The compressor (21) compresses the refrigerant it draws in and discharges the compressed refrigerant. The outdoor fan (25) is rotated by driving a fan motor and transports outdoor air to pass through the outdoor heat exchanger (22). The outdoor heat exchanger (22) exchanges heat between the refrigerant flowing therethrough and the outdoor air transported by the outdoor fan (25). The expansion valve (23) reduces the pressure of the refrigerant.

[0036] The four-way selector valve (24) switches the direction of refrigerant flow between cooling operation and heating operation. In cooling operation, the four-way selector valve (24) is in a first state (the state shown by the dashed lines in FIG. 1 ), and the refrigerant flows in the direction of the dashed arrows. In heating operation, the four-way selector valve (24) is in a second state (the state shown by the solid lines in FIG. 1 ), and the refrigerant flows in the direction of the solid arrows.

[0037] The indoor heat exchanger (50) is included in the indoor unit (30). That is, the indoor unit (30) includes the indoor heat exchanger (50). The indoor unit (30) further includes an indoor fan (42).

[0038] The indoor fan (42) is rotated by driving a fan motor, and transports indoor air through the indoor heat exchanger (50). The indoor heat exchanger (50) exchanges heat between the refrigerant flowing therethrough and the indoor air transported by the indoor fan (42). The air that has passed through the indoor heat exchanger (50) is sent to the indoor space (SI).

[0039] (2) Configuration of the Indoor Unit The configuration of the indoor unit (30) will be described with reference to Figures 2 to 4. In the following description, terms such as "front," "rear," "right," "left," "upper," and "lower" refer to the directions indicated by the arrows in Figures 2 and 3.

[0040] The indoor unit (30) of this embodiment is a wall-mounted indoor air conditioner that is attached to the wall of the indoor space (SI). The indoor unit (30) includes a casing (31), an air filter (41), an indoor heat exchanger (50), an indoor fan (42), a drain pan (43), and a flap (44). The air filter (41), the indoor heat exchanger (50), the indoor fan (42), the drain pan (43), and the flap (44) are housed in the casing (31).

[0041] (2-1) Casing The casing (31) constitutes a flow path forming member that forms the air flow path (34). The casing (31) is formed in the shape of a hollow box that is elongated in the left-right direction. The longitudinal direction of the casing (31) corresponds to the left-right direction.

[0042] The casing (31) is formed with an inlet (32) and an outlet (33). The inlet (32) is an opening for drawing air from the indoor space (SI) into the casing (31). The outlet (33) is an opening for blowing air from the interior of the casing (31) into the indoor space (SI). An air flow path (34) is formed inside the casing (31) from the inlet (32) to the outlet (33).

[0043] (2-2) Air Filter The air filter (41) is disposed in the air flow path (34) upstream of the indoor heat exchanger (50). The air filter (41) is disposed along the air inlet (32) at the rear side of the air inlet (32). The air filter (41) is attached to the casing (31) so that substantially all of the air supplied to the indoor heat exchanger (50) passes through the air filter (41). The air filter (41) is a mesh-like member. The air filter (41) captures dust in the air sucked through the air inlet (32).

[0044] (2-3) Indoor Heat Exchanger The indoor heat exchanger (50) is disposed upstream of the indoor fan (42) in the air flow path (34). As shown in Fig. 3, the indoor heat exchanger (50) is disposed in the casing (31) so as to cover the front to the upper side of the indoor fan (42) and to cover the upper rear side of the indoor fan (42). The indoor heat exchanger (50) in this example is a fin-and-tube heat exchanger.

[0045] The indoor heat exchanger (50) has a plurality of fins (51) and heat transfer tubes (52). The plurality of fins (51) are arranged parallel to one another in a first direction. In this example, the first direction corresponds to the left-right direction. The fins (51) are made of substantially rectangular plates extending in a direction perpendicular to the first direction. An air passage through which air can pass is formed between adjacent fins (51). The fins (51) are made of, for example, aluminum.

[0046] The heat transfer tube (52) has a straight portion (52a) and a U-shaped portion (52b). The straight portion (52a) penetrates the plurality of fins (51) in the plate thickness direction. The extending direction of the straight portion (52a) corresponds to the first direction. The U-shaped portion (52b) has a U-shaped bent shape and integrally connects the ends of the straight portion (52a). The U-shaped portion (52b) is located on the side of the heat exchanger. A refrigerant flows inside the heat transfer tube (52).

[0047] (2-4) Indoor Fan, Drain Pan, and Flap The indoor fan (42) is an example of a fan. The indoor fan (42) is a cross-flow fan. The indoor fan (42) is disposed in approximately the center of the air flow path (34). The indoor fan (42) is rotated by being driven by a fan motor. The direction of the rotation axis of the indoor fan (42) corresponds to the first direction. In other words, the indoor fan (42) has an outer shape whose longitudinal direction is the first direction.

[0048] The drain pan (43) is disposed below the indoor heat exchanger (50). The drain pan (43) is a tray that receives water generated in the casing (31). The drain pan (43) receives condensation water generated on the surface of the indoor heat exchanger (50). A drain pump (not shown) is provided inside the drain pan (43). The drain pump sucks up water accumulated in the drain pan (43) and discharges it to the outside of the room via a drain hose.

[0049] The flap (44) constitutes an airflow direction adjustment unit that adjusts the direction of air blown out from the air outlet (33). The flap (44) is formed in the shape of a long plate extending along the longitudinal direction of the air outlet (33). The flap (44) is disposed at the air outlet (33). The flap (44) rotates when driven by a motor, and adjusts the direction of airflow from the air outlet (33) in the vertical direction. The indoor unit (30) may include, as the airflow direction adjustment unit, a louver that adjusts the direction of airflow from the air outlet (33) in the horizontal direction.

[0050] (3) Ultraviolet Irradiation Device (3-1) Overall Configuration As shown in FIGS. 3 and 4, the air conditioner (10) includes an ultraviolet irradiation device (60).

[0051] The ultraviolet irradiation device (60) is disposed in the air flow path (34) of the indoor unit (30). In this embodiment, the ultraviolet irradiation device (60) is located downstream of the indoor heat exchanger (50). The ultraviolet irradiation device (60) forms a treatment space (R) along a downstream surface (outlet surface) (O1) of the indoor heat exchanger (50) in the air flow direction. The longitudinal direction of the fins (51) corresponding to the surface of the indoor heat exchanger (50) along which the treatment space (R) is formed corresponds to the second direction. The ultraviolet irradiation device (60) defines a part of the air flow path (34) as the treatment space (R) and irradiates the treatment space (R) with ultraviolet light to inactivate viruses and bacteria in the air flowing through the treatment space (R).

[0052] As shown in FIG. 4 , the ultraviolet irradiation device (60) includes an irradiation section (61), a first reflecting section (70), and a second reflecting section (80). The irradiation section (61) and the second reflecting section (80) are disposed at one end of the treatment space (R) in the first direction. The first reflecting section (70) is disposed at the other end of the treatment space (R) in the first direction. The irradiation section (61) irradiates ultraviolet light. The first reflecting section (70) reflects the ultraviolet light irradiated by the irradiation section (61). The second reflecting section (80) reflects the ultraviolet light reflected by the first reflecting section (70).

[0053] (3-2) Irradiation Unit The irradiation unit (61) is supported by a first side plate (31a), which is one of the side plates in the left-right direction of the casing (31). Strictly speaking, the irradiation unit (61) of this embodiment is indirectly supported by a first inner surface (35) of the first side plate (31a) via a first reflecting portion (70). The first inner surface (35) is a surface of the first side plate (31a) that is formed on the air flow path (34) side. The irradiation unit (61) may be directly supported by the first inner surface (35) of the first side plate (31a). The irradiation unit (61) may also be indirectly supported by the first side plate (31a) via another component part in the casing (31).

[0054] The irradiation section (61) is disposed on the first inner surface (35) near the V-shaped portion facing forward of the indoor heat exchanger (50). As shown in FIG. 5 , the irradiation section (61) includes a surface light source (62) and an optical component (OP). The optical component (OP) is an optical element that collects ultraviolet light emitted from the surface light source (62) onto the first reflecting section (70). The irradiation section (61) of this embodiment includes a lens (67) and a reflector (68) as the optical component (OP).

[0055] The surface light source (62) is a light-emitting device having a light-emitting surface (65) that emits ultraviolet light. The surface light source (62) is mounted on a circuit board (66). The circuit board (66) is provided with a heat dissipation member (not shown) for dissipating heat generated by the surface light source (62). As shown in FIG. 6 , the surface light source (62) includes a package substrate (63) and a semiconductor chip (64). The package substrate (63) is provided with wiring and electrodes. The semiconductor chip (64) is mounted on the package substrate (63). The semiconductor chip (64) includes an ultraviolet LED (Light Emitting Diode).

[0056] The light-emitting surface (65) is a portion of the surface of the semiconductor chip (64) that emits light using the ultraviolet LED. The light-emitting surface (65) may be configured by collecting the light-emitting portions of multiple ultraviolet LEDs. In this embodiment, the light-emitting surface (65) is formed in a rectangular shape. The light-emitting surface (65) has a pair of first sides (65a) and a pair of second sides (65b). The pair of first sides (65a) and the pair of second sides (65b) are opposite sides. The first sides (65a) and the second sides (65b) extend in directions perpendicular to each other.

[0057] In this example, the light-emitting surface (65) is formed in a square shape with a first side (65a) and a second side (65b) having the same length. Each of the first side (65a) and the second side (65b) is, for example, approximately 1 mm. The surface light source (62) is provided such that the first side (65a) of the light-emitting surface (65) extends in the second direction and the second side (65b) extends in a third direction perpendicular to the first and second directions.

[0058] The ultraviolet rays emitted from the surface light source (62) have a wavelength of 200 nm or more and 300 nm or less. As shown in Figure 7, the shorter the wavelength of ultraviolet rays, the more easily they are refracted by a lens. Furthermore, ultraviolet rays with a relatively short wavelength of 200 nm or more and 300 nm or less are deep ultraviolet rays (UV-C) or ultraviolet rays with wavelengths close to deep ultraviolet rays (UV-C), and act to inactivate viruses and bacteria in the air.

[0059] For example, the ultraviolet light emitted by the surface light source (62) is deep ultraviolet light (UV-C), and its peak wavelength is 280 nm or less. This can improve the sterilizing effect of the air. From the viewpoint of improving the sterilizing effect of the air, the peak wavelength of the ultraviolet light emitted by the surface light source (62) is preferably 255 nm or more and 275 nm or less. The peak wavelength of the ultraviolet light emitted by the surface light source (62) may be 230 nm or less. This can improve the safety of human exposure in the event that the ultraviolet light leaks outside the casing (31).

[0060] The lens (67) is disposed in front of the light-emitting surface (65) of the surface light source (62). The lens (67) is oriented such that its optical axis (A0) is aligned with the direction of ultraviolet light emitted by the surface light source (62). The lens (67) is a transparent body that refracts ultraviolet light emitted from the surface light source (62) and focuses the refracted ultraviolet light toward the first reflecting portion (70). The lens (67) of this embodiment is a biconvex lens. The lens (67) has a first surface (67a) and a second surface (67b). The first surface (67a) and the second surface (67b) are surfaces facing away from each other in the thickness direction of the lens (67) and are each convex.

[0061] The first surface (67a) is located on the surface light source (62) side. The second surface (67b) is located on the first reflecting portion (70) side. The first surface (67a) and the second surface (67b) are each an even-order aspherical surface. Applying an even-order aspherical surface to the lens (67) in this manner can correct spherical aberration. The radius of curvature of the first surface (67a) is larger than the radius of curvature of the second surface (67b). If the radius of curvature of the first surface (67a) is smaller than the radius of curvature of the second surface (67b), the distance between the principal point (P1) of the lens (67) and the surface light source (62) becomes shorter, and the magnification of the paraxial image surface (90) becomes larger. Therefore, this would not be suitable for generating a paraxial image surface (90) (described below) that fits within the range of the first reflecting surface (71) provided in the limited space inside the indoor unit (30).

[0062] The reflector (68) is disposed so as to surround the space in front of the surface light source (62) (light-emitting surface (65)). The reflector (68) is a reflective member that reflects ultraviolet light emitted from the surface light source (62) and concentrates the reflected ultraviolet light toward the first reflecting portion (70). The reflector (68) has a reflective surface (68a) that reflects ultraviolet light. The reflective surface (68a) has a curved surface that corresponds to or approximates a paraboloid of revolution. In Figure 5 and other figures, the entire reflector (68) is shown in the shape of a radiating surface of revolution. However, the reflector (68) can have any shape necessary to avoid interference when combined with the surface light source (62) and the lens (67), as long as the reflective surface (68a) has a shape that corresponds to a portion of a paraboloid of revolution.

[0063] As shown in Fig. 8, the lens (67) and the reflector (68) cause the irradiation unit (61) to irradiate ultraviolet light toward the other end of the treatment space (R) in the first direction. In Fig. 8, the general direction of travel of the ultraviolet light is indicated by a dashed arrow. This also applies to Figs. 5 and 11.

[0064] The lens (67) and reflector (68) are configured to generate a paraxial image plane (90) of the light-emitting surface (65) of the surface light source (62) on the irradiated surface (71a) that is irradiated with ultraviolet light from the first reflecting section (70). The lens (67) and reflector (68) form an image of the light-emitting surface (65) on or near the irradiated surface (71a) of the first reflecting section (70). The edges of the image plane formed on the irradiated surface (71a) are somewhat blurred due to aberration. The paraxial image plane (90) is an image plane that includes such blurring (aberration).

[0065] The paraxial image surface (90) of this embodiment has a rectangular shape similar to the shape of the light-emitting surface (65) of the surface light source (62). The paraxial image surface (90) has a pair of third sides (90a) and a pair of fourth sides (90b). The pair of third sides (90a) and the pair of fourth sides (90b) are opposite sides. The third sides (90a) and the fourth sides (90b) extend in directions perpendicular to each other. The third side (90a) is a side extending in the second direction. The fourth side (90b) is a side extending in the third direction. The paraxial image surface (90) of this example is formed in a square shape in which the length of the third side (90a) and the length of the fourth side (90b) are equal.

[0066] As shown in FIG. 9 , the paraxial image plane (90) includes a first image plane area (91) generated by light collection by the lens (67) and the reflector (68) and a second image plane area (92) generated by light collection by the lens (67). The first image plane area (91) forms the central portion of the paraxial image plane (90). The second image plane area (92) forms the portion of the paraxial image plane (90) other than the first image plane area (91). The illuminance distribution of ultraviolet light in the paraxial image plane (90) is relatively high in the first image plane area (91) and relatively low in the second image plane area (92). The illuminance distribution of ultraviolet light is also relatively low at the edge portions of the first image plane area (91) compared to other portions.

[0067] As shown in Fig. 10, the distance from the light-emitting surface (65) of the surface light source (62) to the principal point (P1) of the lens (67) is denoted by La [mm], and the distance from the principal point (P1) of the lens (67) to the illuminated surface (71a) of the first reflecting portion (70) is denoted by Lb [mm]. Strictly speaking, the latter distance Lb is the distance from the principal point (P1) of the lens (67) to a position on the optical axis (A0) of the lens (67) on the first reflecting surface (71). In this case, the magnification β of the paraxial image plane (90) is expressed by the following equation 1: β = Lb / La (Equation 1)

[0068] The irradiation distance of ultraviolet light from the irradiation unit (61) to the first reflecting unit (70) is denoted by Li [mm]. The irradiation distance Li is the distance between the light-emitting surface (65) of the surface light source (62) and the irradiated surface (71a) of the first reflecting unit (70), or more precisely, the distance from the light-emitting surface (65) to a position on the irradiated surface (71a) on the optical axis (A0) of the lens (67). In this case, Lb = Li - La holds. Therefore, the distance La from the light-emitting surface (65) to the principal point (P1) of the lens (67) is expressed by the following equation 2: La = Li / (β + 1) (Equation 2)

[0069] The length of the second side (65b) of the light-emitting surface (65) is defined as Wl [mm]. The length of the second side (65b) corresponds to the maximum width of the light-emitting surface (65) in a predetermined direction. The predetermined direction here may be understood as the direction perpendicular to the first direction in which the width is narrowest in design terms in forming the processing space (R) in the air flow path (34). Furthermore, the length of the fourth side (90b) of the paraxial image plane (90) is defined as Wi. In this case, the magnification β of the paraxial image plane (90) can also be expressed by the following equation 3. By combining this equation 3 with the above equation 2, the distance La from the light-emitting surface (65) to the principal point (P1) of the lens (67) can be expressed by the following equation 4: β = Wi / Wl (Equation 3) La = Li × Wl / (Wi + Wl) (Equation 4)

[0070] In this embodiment, the lengths of the third side (90a) and the fourth side (90b) of the paraxial image surface (90) are each 20 mm or more and 70 mm or less. The length of the fourth side (90b) of the paraxial image surface (90) corresponds to the width of the paraxial image surface (90) in a predetermined direction. Therefore, the distance La between the principal point (P1) of the lens (67) and the light-emitting surface (65) satisfies the relationship expressed by the following formula 5 based on the length of the fourth side (90b) of the paraxial image surface (90). The positional relationship between the surface light source (62) and the lens (67) is designed to satisfy the relationship expressed by formula 5. Li×Wl / (70+Wl)≦La≦Li×Wl / (20+Wl) (Formula 5)

[0071] Furthermore, the distance from the vertex (P2) of the reflecting surface (68a) of the reflector (68) to the light-emitting surface (65) of the surface light source (62) is defined as Lc [mm], and the distance from the vertex (P2) of the reflecting surface (68a) to the illuminated surface (71a) of the first reflecting portion (70) is defined as Ld [mm]. Strictly speaking, the latter distance Ld is the distance from the vertex (P2) of the reflector (68) to a position on the optical axis (A0) of the lens (67) of the first reflecting surface (71). In this case, the distance Lc from the vertex (P2) of the reflector (68) to the light-emitting surface (65) of the surface light source (62) is expressed by the following equation 6 in relation to the magnification β of the paraxial image plane (90). This equation 6 is obtained by assuming that light emitted by the surface light source (62) is emitted from the light-emitting surface (65) in a 360° range. Lc = Ld / β (Equation 6)

[0072] Furthermore, the relationship Ld = Lc + Li holds between the two distances Lc, Ld and the illumination distance Li. Therefore, the distance Lc from the vertex (P2) of the reflecting surface (68a) to the light-emitting surface (65) of the surface light source (62) can also be expressed by the following formula 7. By combining formula 7 with formula 3, the distance Lc from the vertex (P2) of the reflecting surface (68a) to the light-emitting surface (65) of the surface light source (62) can be expressed by the following formula 8. Lc = Li / (β - 1) (formula 7) Lc = Li × Wl / (Wi - Wl) (formula 8)

[0073] As described above, the lengths of the third side (90a) and the fourth side (90b) of the paraxial image plane (90) are each 20 mm or more and 70 mm or less. Therefore, the distance Lc between the vertex (P2) of the reflecting surface (68a) and the light-emitting surface (65) satisfies the relationship expressed by the following formula 9 based on the length of the fourth side (90b) of the paraxial image plane (90). The positional relationship between the surface light source (62) and the reflector (68) is designed to satisfy the relationship expressed by formula 9. Li×Wl / (70−Wl)≦Lc≦Li×Wl / (20−Wl) (Formula 9)

[0074] The surface light source (62) has a predetermined light distribution angle. The light distribution angle is the spread angle of light (ultraviolet rays) emitted from the surface light source (62). Specifically, the light distribution angle is the angle formed by the traveling direction of the ultraviolet rays emitted from the surface light source (62) with respect to a first optical axis (A1), which is an optical axis perpendicular to the light-emitting surface (65) of the surface light source (62), when the first optical axis (A1) is set at 0°. Narrow-angle ultraviolet rays emitted from the surface light source (62) traveling at an angle close to the first optical axis (A1) are distributed to the lens (67). Wide-angle ultraviolet rays emitted from the surface light source (62) traveling at an angle far from the first optical axis (A1) are distributed to the reflecting surface (68a) of the reflector (68).

[0075] The boundary between the angle at which ultraviolet light from the surface light source (62) is distributed to the lens (67) and the angle at which it is distributed to the reflector (68) is referred to as the distribution boundary (BL). The distribution boundary (BL) is a boundary relating to the light distribution between the lens (67) and the reflector (68) at a position on the optical axis (A0) of the lens (67) on the light-emitting surface (65) of the surface light source (62). As shown in FIG. 10 , the distribution boundary (BL) is represented by an imaginary line connecting a position on the optical axis (A0) of the lens (67) on the light-emitting surface (65) of the surface light source (62) to the peripheral edge of the lens (67). The angle of the distribution boundary (BL) is the angle between the distribution boundary (BL) and the optical axis (A0) of the surface light source (62). Note that the first optical axis (A1) of the surface light source (62) and the optical axis (A0) of the lens (67) coincide with each other.

[0076] The angle of the distribution boundary (BL) is θ [°], and the diameter of the lens (67) is Dl [mm]. In this case, the following formula 10 holds. By combining formula 10 with formula 4 above, the angle θ of the distribution boundary (BL) is expressed by formula 11 below. In this embodiment, the diameter of the lens (67) is designed to fit within the maximum size of the paraxial image plane (90) (length of one side is 70 mm). Therefore, the angle θ of the distribution boundary (BL) satisfies the relationship expressed by formula 12 below (where θ≦89): tan(θ)=(Dl / 2) / La (formula 10) θ=arctan{(Dl / 2) / (Li×Wl / (Wi+Wl))} (formula 11) θ≦arctan(35×(70−Wl) / Li×Wl) (formula 12)

[0077] (3-3) First Reflecting Portion The first reflecting portion (70) is supported by the second side plate (31b), which is the other side plate in the left-right direction of the casing (31). The first reflecting portion (70) may be directly supported by the second inner surface (36) of the second side plate (31b) or indirectly supported by the second inner surface (36) of the second side plate (31b) via another member (adhesive tape or a fastener). The second inner surface (36) is a surface of the second side plate (31b) that is formed on the air flow path (34) side. The first reflecting portion (70) is formed in the shape of a rectangular plate extending along the second direction. In this embodiment, the first reflecting portion (70) is located above the front side of the indoor fan (42) and downstream of a portion that is inclined so that the upper end of the indoor heat exchanger (50) is located rearward of the lower end.

[0078] The first reflecting portion (70) reflects the ultraviolet light emitted from the irradiating portion (61) toward one end in the first direction. The first reflecting portion (70) has a first reflecting surface (71). When viewed in a cross section in the third direction, the first reflecting surface (71) has a curved shape that is recessed toward the other end in the first direction. This makes it possible to prevent the ultraviolet light reflected by the first reflecting surface (71) from being significantly inclined outward in the second direction.

[0079] When viewed in cross section in the second direction, the first reflecting surface (71) preferably has a curved shape that is concave toward the other end in the first direction. In other words, the first reflecting surface (71) preferably has a spherical or parabolic shape. A first reflecting surface (71) having such a shape can prevent the reflected ultraviolet rays from significantly tilting outward in the third direction, i.e., from spreading in the traveling direction.

[0080] The first reflecting surface (71) is configured as a concave surface having the curved shape. The first reflecting surface (71) includes an irradiated surface (71a) that is irradiated with ultraviolet light from the surface light source (62). The irradiated surface (71a) is a part of the first reflecting surface (71), and is therefore configured as a concave surface. The radius of curvature R1 of the first reflecting surface (71) including the irradiated surface (71a) satisfies the relationship expressed by the following formula 13: 0.5×Li≦R1≦2×Li (Formula 13)

[0081] The radius of curvature R1 of the first reflecting surface (71) is preferably larger than Li. If the radius of curvature R1 of the first reflecting surface (71) is smaller than Li, the focal point of the first reflecting surface (71) will be too close to the first reflecting section (70), and the ultraviolet rays reflected by the first reflecting surface (71) will be significantly tilted outward in the second direction. The radius of curvature R1 of the first reflecting surface (71) is preferably equal to or smaller than 2×Li. If the radius of curvature R1 of the first reflecting surface (71) is larger than 2×Li, the ultraviolet rays reflected by the first reflecting surface (71) will be too close to the irradiation section (61), which may accelerate deterioration of the irradiation section (61) due to the ultraviolet rays.

[0082] The specular reflectance r1 of the first reflecting surface (71) is preferably 50% or more. The specular reflectance r1 [%] is expressed by the following formula 14: r1=(Ea2 / Ea1)×100 ... (Formula 14) Here, Ea1 is the amount of ultraviolet light [mW] entering the first reflecting section (70). Ea2 is the amount of ultraviolet light [mW] reflected by the first reflecting section (70).

[0083] (3-4) Second Reflecting Section The second reflecting section (80) is supported by one of the side plates of the casing (31) in the left-right direction. The second reflecting section (80) may be directly supported by the side plate of the casing (31) or may be indirectly supported by the side plate via another member (such as an adhesive tape or a fixing device). The second reflecting section (80) is formed in the shape of a rectangular plate extending along the second direction.

[0084] The second reflecting portion (80) of this embodiment is located above and in front of the indoor fan (42), downstream of a portion that is inclined so that the upper end of the indoor heat exchanger (50) is located rearward of the lower end. The second reflecting portion (80) faces the first reflecting portion (70) across the treatment space (R). When viewed in the first direction, at least a portion of the first reflecting portion (70) overlaps with the second reflecting portion (80). In this case, it is preferable that the first reflecting portion (70) entirely overlaps with the second reflecting portion (80).

[0085] The second reflecting portion (80) reflects the ultraviolet light reflected by the first reflecting portion (70) toward the other end in the first direction. The second reflecting portion (80) has a second reflecting surface (81). When viewed in a cross section in the third direction, the second reflecting surface (81) has a curved shape that is recessed toward one end in the first direction. This makes it possible to prevent the ultraviolet light reflected by the second reflecting surface (81) from being significantly tilted outward in the second direction.

[0086] When viewed in cross section in the second direction, the second reflecting surface (81) preferably has a curved shape that is concave toward the other end in the first direction. In other words, the second reflecting surface (81) preferably has a spherical or parabolic shape. A second reflecting surface (81) having such a shape can prevent the reflected ultraviolet rays from significantly tilting outward in the third direction, i.e., from spreading in the traveling direction.

[0087] The second reflecting surface (81) is formed by a concave surface having the above-mentioned curved shape. The radius of curvature R2 of the second reflecting surface (81) satisfies the relationship expressed by the following formula 15. The radius of curvature R2 of the second reflecting surface (81) is preferably larger than Li. This is because if the radius of curvature R2 of the second reflecting surface (81) is smaller than Li, the focal point of the second reflecting surface (81) will be too close to the second reflecting portion (80), and the ultraviolet light reflected by the second reflecting surface (81) will be significantly tilted outward in the second direction. 0.5 × Li ≦ R2 ≦ 2 × Li (Formula 15)

[0088] The regular reflectance r2 of the second reflecting surface (81) is preferably 50% or more. The regular reflectance r2 [%] is expressed by the following formula 16: r2=(Eb2 / Eb1)×100 (Formula 16) where Eb1 is the amount of ultraviolet light [mW] entering the second reflecting portion (80). Eb2 is the amount of ultraviolet light [mW] reflected by the second reflecting portion (80).

[0089] (6) Operation of Ultraviolet Irradiation Device In the air conditioner (10), the ultraviolet irradiation device (60) operates in cooling operation or heating operation. The ultraviolet irradiation device (60) irradiates ultraviolet rays from the irradiation section (61) toward the treatment space (R) while the indoor fan (42) is operating.

[0090] As shown in Fig. 11 , the irradiation section (61) irradiates the treatment space (R) with ultraviolet light from one end (the first inner surface (35) side) to the other end (the second inner surface (36) side) in the first direction. For example, a first optical axis (A1) of the ultraviolet light from the irradiation section (61) coincides with the first direction. The irradiation section (61) irradiates the treatment space (R) with ultraviolet light across the space between both side plates of the casing (31) in the left-right direction, thereby forming the treatment space (R) across the entirety of the indoor heat exchanger (50) in the first direction.

[0091] The ultraviolet light emitted from the irradiation section (61) is reflected by the first reflection section (70). The first reflection section (70) reflects the ultraviolet light from the other end side (the second inner surface (36) side) of the treatment space (R) in the first direction toward one end side (the first inner surface (35) side).

[0092] The second optical axis (A2), which is the optical axis of the ultraviolet light reflected by the first reflecting portion (70), is offset by a predetermined first angle θ1 in the second direction from the first optical axis (A1) of the irradiating portion (61). Specifically, the second optical axis (A2) is offset by the first angle θ1 toward the other end in the second direction from the first optical axis (A1). The first angle θ1 is a predetermined angle greater than 0°. This allows the treatment space (R) of the ultraviolet irradiating device (60) to expand in the second direction, i.e., in the longitudinal direction of the fin (51). The ultraviolet light reflected by the first reflecting portion (70) reaches from the first reflecting surface (71) to the second reflecting surface (81), thereby forming the treatment space (R) expanded in the second direction over the entire first direction of the indoor heat exchanger (50). The first angle θ1 is preferably 1° or greater.

[0093] The ultraviolet light reflected by the first reflecting portion (70) is reflected by the second reflecting portion (80). The second reflecting portion (80) reflects the ultraviolet light from one end side (the first inner surface (35) side) of the treatment space (R) in the first direction toward the other end side (the second inner surface (36) side).

[0094] The third optical axis (A3), which is the optical axis of the ultraviolet light reflected by the second reflecting portion (80), is offset by a predetermined second angle θ2 in the second direction from the second optical axis (A2) of the first reflecting portion (70). Specifically, the third optical axis (A3) is offset by the second angle θ2 toward the other end in the second direction from the second optical axis (A2). The second angle θ2 is a predetermined angle greater than 0°. This allows the treatment space (R) of the ultraviolet irradiation device (60) to expand in the second direction, i.e., in the longitudinal direction of the fin (51). The ultraviolet light reflected by the second reflecting portion (80) reaches from the second reflecting surface (81) to the first reflecting surface (71), thereby forming the treatment space (R) expanded in the second direction over the entire first direction of the indoor heat exchanger (50). The second angle θ2 is preferably 1° or greater.

[0095] The first angle θ1 and the second angle θ2 are shifted to the same side (the other end side) in the second direction. Therefore, the first reflecting portion (70) and the second reflecting portion (80) can expand the treatment space (R) toward the other end side in the second direction. Note that the angles θ1 and θ2 are exaggerated in FIG. 11 .

[0096] The ultraviolet light reflected by the second reflecting portion (80) reaches the first reflecting portion (70) again. The first reflecting portion (70) reflects the ultraviolet light so as to be shifted by a predetermined angle toward the other end in the second direction. The ultraviolet light reflected by the first reflecting portion (70) reaches the second reflecting portion (80) again. The second reflecting portion (80) reflects the ultraviolet light so as to be shifted by a predetermined angle toward one end in the second direction. The ultraviolet light reflected by the second reflecting portion (80) reaches the first reflecting portion (70) again. The first reflecting portion (70) reflects the ultraviolet light so as to be shifted by a predetermined angle toward one end in the second direction.

[0097] As described above, in the ultraviolet irradiation device (60), ultraviolet rays are reflected alternately between the first reflecting section (70) and the second reflecting section (80).

[0098] Features of First Embodiment In the ultraviolet irradiation device (60) of this embodiment, the irradiation unit (61) is disposed at one end of the treatment space (R), and the first reflecting unit (70) is disposed at the other end of the treatment space (R). The irradiation unit (61) collects ultraviolet light emitted from the surface light source (62) toward the first reflecting unit (70) using an optical component (OP). The optical component (OP) generates a paraxial image plane (90) of the light-emitting surface (65) on the irradiated surface (71a) onto which the ultraviolet light from the first reflecting unit (70) is irradiated. This prevents the ultraviolet light reflected by the irradiated surface (71a) of the first reflecting unit (70) from spreading in the direction of travel. This allows ultraviolet light to be efficiently irradiated onto the air flowing through the treatment space (R).

[0099] In the ultraviolet irradiation device (60) of this embodiment, the ultraviolet light emitted from the surface light source (62) has a relatively short wavelength of 200 nm or more and 300 nm or less. The shorter the wavelength of the ultraviolet light, the more easily it is refracted by the lens (67). Therefore, by using the lens (67), it is easy to adjust the ultraviolet light emitted from the surface light source (62) so that a paraxial image plane (90) of the light-emitting surface (65) is generated on the irradiated surface (71a) of the first reflecting portion (70). Furthermore, the ultraviolet light with the relatively short wavelength is suitable for inactivating viruses and bacteria in the air.

[0100] In the ultraviolet irradiation device (60) of this embodiment, the length of the fourth side (90d) (corresponding to the width in a predetermined direction) of the paraxial image surface (90) is 20 nm or more and 70 mm or less. When a paraxial image surface (90) of such dimensions is generated on the irradiation surface (71a), the ultraviolet irradiation device (60) can be configured relatively compactly. This allows the ultraviolet irradiation device (60) to be installed even in the limited space inside existing equipment such as an air conditioner (10).

[0101] In the ultraviolet irradiation device (60) of this embodiment, when an irradiation distance, which is the distance between the light-emitting surface (65) of the surface light source (62) and the irradiated surface (71 a) of the first reflecting section (70), is Li [mm] and a length of the second side (65 b) of the light-emitting surface (65) (corresponding to the maximum width in a predetermined direction) is Wl [mm], a distance La [mm] between the principal point (P1) of the lens (67) and the light-emitting surface (65) satisfies the relationship Li × Wl / (70 + Wl) ≦ La ≦ Li × Wl / (20 + Wl). This allows a paraxial image plane (90) in which the length of the fourth side (90 b) is 20 nm or more and 70 mm or less to be generated on the irradiated surface (71 a) of the first reflecting section (70).

[0102] In the ultraviolet irradiation device (60) of this embodiment, when an irradiation distance, which is the distance between the light-emitting surface (65) of the surface light source (62) and the irradiated surface (71 a) of the first reflecting section (70), is Li [mm] and a length of a second side (65 b) of the light-emitting surface (65) (corresponding to the maximum width in a predetermined direction) is Wl [mm], a distance Lb [mm] between the vertex (P2) of a paraboloid of revolution that corresponds to or approximates the reflecting surface (68 a) and the light-emitting surface (65) satisfies the relationship Li×Wl / (70−Wl)≦Lb≦Li×Wl / (20−Wl). This allows a paraxial image plane (90) in which the length of a fourth side (90 b) is 20 nm or more and 70 mm or less to be generated on the irradiated surface (71 a) of the first reflecting section (70).

[0103] In the ultraviolet irradiation device (60) of this embodiment, when an irradiation distance, which is the distance between the light-emitting surface (65) of the surface light source (62) and the irradiated surface (71 a) of the first reflecting portion (70), is Li [mm] and the length of the second side (65 b) of the light-emitting surface (65) (corresponding to the maximum width in a predetermined direction) is Wl [mm], an angle θ [°] that forms a light distribution boundary between the lens (67) and the reflector (68) at a position on the optical axis (A0) of the lens (67) on the light-emitting surface (65) satisfies the relationship θ≦arctan (35×(70−Wl) / Li×Wl) (where θ≦89). According to this, the diameter of the lens (67) is equal to or smaller than 70 mm, which is the maximum size of the paraxial image plane (90) in the third direction. This allows a paraxial image plane 90 having a width in a predetermined direction of 20 nm or more and 70 mm or less to be generated on the irradiated surface 71 a of the first reflecting section 70 using a lens 67 having a relatively small diameter, which is advantageous for realizing a compact ultraviolet irradiation device 60.

[0104] In the ultraviolet irradiation device (60) of this embodiment, the radius of curvature R1 of the irradiated surface (71a) of the first reflecting portion (70) is greater than 0.5 times the irradiation distance Li and is equal to or less than twice the irradiation distance Li. The irradiated surface (71a) having such a radius of curvature R1 can reflect ultraviolet light irradiated from the irradiating portion (61) toward the vicinity of the irradiating portion (61). This allows the ultraviolet irradiation device (60) to have a compact configuration and to be used even in a relatively narrow treatment space (R).

[0105] In the ultraviolet irradiation device (60) of this embodiment, the second reflecting section (80) is disposed at one end of the treatment space (R) in the first direction, i.e., on the same side as the irradiation section (61). The ultraviolet rays reflected by the first reflecting section (70) are reflected again by the second reflecting section (80) toward the other end in the first direction. This allows the ultraviolet rays emitted from the irradiation section (61) to be repeatedly reflected between the first reflecting section (70) and the second reflecting section (80) and to remain in the treatment space for a relatively long time. This is advantageous for efficiently irradiating the air flowing through the treatment space (R) with ultraviolet rays.

[0106] In the ultraviolet irradiation device (60) of this embodiment, the radius of curvature of the first surface (67a) of the lens (67) facing the surface light source (62) is larger than the radius of curvature of the second surface (67b) facing the first reflecting section (70). When the radius of curvature of the first surface (67a) is larger than the radius of curvature of the second surface (67b), the distance between the principal point (P1) of the lens (67) and the surface light source (62) increases, and the magnification of the paraxial image plane (90) decreases. Therefore, the ultraviolet irradiation device (60) can be configured compactly while preventing ultraviolet light emitted from the irradiation section (61) from leaking from the first reflecting section (70).

[0107] In the ultraviolet irradiation device (60) of this embodiment, the first surface (67a) and the second surface (67b) of the lens (67) are each an even-order aspheric surface. This reduces the aberration contained in the paraxial image plane (90). This is advantageous in preventing the ultraviolet light reflected by the irradiated surface (71a) of the first reflecting part (70) from spreading in the direction of travel.

[0108] The air conditioner (10) of this embodiment uses an ultraviolet ray irradiation device (60). The ultraviolet ray irradiation device (60) can efficiently irradiate ultraviolet rays to the air flowing through the treatment space (R). Therefore, the air conditioner (10) can effectively inactivate viruses and bacteria in the air by ultraviolet rays.

[0109] 12 , the ultraviolet irradiation device (60) may be disposed in front of the indoor fan (42) and upstream of a portion of the indoor heat exchanger (50) that is inclined such that the upper end of the indoor heat exchanger (50) is located forward of the lower end, and a treatment space (R) may be formed along the upstream surface (inlet surface) (I2) of the portion in the air flow direction. The irradiation section (61) may be disposed, for example, near the front lower end of the indoor heat exchanger (50). The irradiation section (61) may be disposed near a V-shaped portion that faces forward of the indoor heat exchanger (50).

[0110] In this configuration, a treatment space (R) is formed above the drain pan (43), which can suppress the growth of bacteria in the drain pan (43).In addition, ultraviolet light is less likely to leak to the outside of the casing (31) through the inlet (32).

[0111] Other Embodiments A separate flow path forming member for partitioning the air flow path (34) may be provided inside the casing (31). In this case, the flow path forming member inside the casing (31) may be formed with a first inner surface (35) that supports the irradiation section (61) and the second reflecting section (80) and a second inner surface (36) that supports the first reflecting section (70). The flow path forming member may be any member that forms a surface that defines the air flow path (34). The flow path forming member may be, for example, a partition plate that separates the air flow path (34) from an electrical component room, a support plate for the indoor heat exchanger (50), or a frame for a drain pan.

[0112] The heat transfer tube (52) does not have to be a circular tube, but may be a flat multi-hole tube.

[0113] The ultraviolet light emitted from the surface light source (62) may have a wavelength of less than 200 nm or greater than 300 nm, as long as it is expected to have the effect of inactivating viruses and bacteria in the air.

[0114] The paraxial image plane (90) generated on the irradiated surface (71 a) of the first reflecting portion (70) is not limited to a square shape, and may be rectangular, circular, elliptical, or any other shape depending on the shape of the light-emitting surface (65) of the surface light source (62). In addition, when incorporating the paraxial image plane (90) into an existing device such as an air conditioner (10), the size of the paraxial image plane (90) is adjusted depending on the space available as the processing space (R).

[0115] The optical component (OP) may be only a reflector (68), only a lens (67), or any other elemental component as long as it can collect ultraviolet rays emitted from the surface light source (62) toward the first reflecting portion (70) and generate a paraxial image plane of the light emitting surface (65) of the surface light source (62) on the irradiated surface (71 a) of the first reflecting portion (70).

[0116] The control unit (C) may cause the ultraviolet irradiation device (60) to irradiate ultraviolet rays while the indoor fan (42) is stopped, which can suppress the proliferation of bacteria while the air conditioner (10) is stopped.

[0117] The first reflecting surface (71) of the first reflecting portion (70) may be a planar surface inclined with respect to the second direction. The second reflecting surface (81) of the second reflecting portion (80) may be a planar surface inclined with respect to the second direction.

[0118] The ultraviolet irradiation device (60) is not limited to being provided at the above-described position in the casing (31), and may be provided at another position in the casing (31). The ultraviolet irradiation device (60) may form an ultraviolet treatment space (R) along the outlet surface or the inlet surface of the outdoor heat exchanger (22) of the outdoor unit (20).

[0119] The air conditioner (10) may be an indoor multi-type having two or more indoor units (30) or an outdoor multi-type having two or more outdoor units (20). The air conditioner (10) does not have to be a separate type, but may be an integrated type in which a user-side heat exchanger and a heat-source-side heat exchanger are housed in a single casing. The air conditioner (10) does not have to be a stationary type. Specifically, the air conditioner (10) may be a container refrigeration system that cools the interior space of a transport container, or may be an air conditioner for a vehicle.

[0120] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and details are possible without departing from the spirit and scope of the claims. Furthermore, the above embodiments and modifications may be combined or substituted as appropriate as long as the functionality of the subject matter of the present disclosure is not impaired.

[0121] The above-mentioned descriptions such as "first," "second," "third," etc. are used to distinguish the words to which these descriptions are attached, and do not limit the number or order of the words.

[0122] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for ultraviolet irradiation devices and air conditioners.

[0123] R Processing space OP Optical component P1 Principal point of lens P2 Vertex of reflecting surface 31 Casing 32 Intake port 33 Outlet 34 Air flow path 60 Ultraviolet irradiation device 61 Irradiation section 62 Surface light source 65 Light emitting surface 67 Lens 67a First surface 67b Second surface 68 Reflector 68a Reflecting surface 70 First reflecting section 71a Irradiated surface 80 Second reflecting section 90 Paraxial image plane

Claims

1. An ultraviolet irradiation device that irradiates ultraviolet rays into a processing space (R) through which air flows, comprising: an irradiation section (61) that is arranged at one end of the processing space (R) in a first direction and irradiates ultraviolet rays toward the other end in the first direction; and a first reflection section (70) that is arranged at the other end of the processing space (R) in the first direction and reflects the ultraviolet rays irradiated from the irradiation section (61) toward the one end in the first direction, wherein the irradiation section (61) has a surface light source (62) having a light-emitting surface (65) that emits ultraviolet rays, and an optical component (OP) that collects the ultraviolet rays emitted from the surface light source (62) toward the first reflection section (70), and the optical component (OP) is configured to generate a paraxial image plane (90) of the light-emitting surface (65) on an irradiated surface (71a) that is irradiated with ultraviolet rays from the first reflection section (70).

2. An ultraviolet irradiation device according to claim 1, wherein the irradiation section (61) has, as the optical component (OP), a lens (67) that refracts the ultraviolet light emitted from the surface light source (62), and the ultraviolet light emitted from the surface light source (62) has a wavelength of 200 nm or more and 300 nm or less.

3. An ultraviolet irradiation device according to claim 1 or 2, wherein the width of the paraxial image plane (90) in a predetermined direction is 20 mm or more and 70 mm or less.

4. An ultraviolet irradiation device according to claim 3, wherein the irradiation section (61) has, as the optical component (OP), a lens (67) that refracts ultraviolet light emitted from the surface light source (62), and the lens (67) is arranged on the front side of the light-emitting surface (65), and when an irradiation distance that is the distance between the light-emitting surface (65) of the surface light source (62) and the irradiated surface (71a) of the first reflecting section (70) is Li [mm] and a maximum width of the light-emitting surface (65) in a predetermined direction is Wl [mm], a distance La [mm] between a principal point (P1) of the lens (67) and the light-emitting surface (65) satisfies the relationship Li × Wl / (70 + Wl) ≦ La ≦ Li × Wl / (20 + Wl).

5. In the ultraviolet irradiation device according to claim 3 or 4, the irradiation section (61) has a reflector (68) as the optical component (OP) that reflects ultraviolet light emitted from the surface light source (62), the reflector (68) is arranged so as to surround the space in front of the light-emitting surface (65), the reflecting surface (68a) of the reflector (68) that reflects ultraviolet light presents a curved surface that corresponds to or approximates a paraboloid of revolution, and when an irradiation distance that is the distance between the light-emitting surface (65) of the surface light source (62) and the irradiated surface (71a) of the first reflecting section (70) is Li [mm] and the maximum width of the light-emitting surface (65) in a predetermined direction is Wl [mm], the distance Lb [mm] between the vertex (P2) of the paraboloid of revolution that corresponds to or approximates the reflecting surface (68a) and the light-emitting surface (65) is An ultraviolet irradiation device that satisfies the relationship Li×Wl / (70−Wl)≦Lb≦Li×Wl / (20−Wl).

6. In the ultraviolet irradiation device according to any one of claims 3 to 5, the irradiation section (61) has, as the optical component (OP), a lens (67) that refracts the ultraviolet light emitted from the surface light source (62) and a reflector (68) that reflects the ultraviolet light emitted from the surface light source (62), the lens (67) is arranged on the front side of the light-emitting surface (65), and the reflector (68) is arranged so as to surround the space on the front side of the light-emitting surface (65) and the lens (67), an irradiation distance, which is the distance between the light-emitting surface (65) of the surface light source (62) and the irradiated surface (71 a) of the first reflecting portion (70), is Li [mm], and a maximum width of the light-emitting surface (65) in a predetermined direction is Wl [mm], an angle θ [°] that is a light distribution boundary between the lens (67) and the reflector (68) at a position on the optical axis of the lens (67) on the light-emitting surface (65) satisfies the relationship θ≦arctan(35×(70−Wl) / Li×Wl) (where θ≦89).

7. An ultraviolet irradiation device according to any one of claims 1 to 6, wherein the irradiated surface (71a) is configured as a concave surface having a predetermined curvature, and when an irradiation distance, which is the distance between the light emitting surface (65) of the surface light source (62) and the irradiated surface (71a) of the first reflecting section (70), is Li [mm], the radius of curvature R1 of the irradiated surface (71a) satisfies the relationship 0.5 × Li ≦ R1 ≦ 2 × Li.

8. An ultraviolet irradiation device according to any one of claims 1 to 7, comprising a second reflecting section (80) disposed at one end of the processing space (R) in the first direction, and reflecting ultraviolet light reflected by the first reflecting section (70) towards the other end in the first direction.

9. An ultraviolet irradiation device according to any one of claims 1 to 8, wherein the irradiation section (61) has, as the optical component (OP), a lens (67) that refracts ultraviolet light emitted from the surface light source (62), the lens (67) has a first surface (67a) facing the surface light source (62) and a second surface (67b) facing the first reflecting section (70), the lens (67) being a biconvex lens in which the first surface (67a) and the second surface (67b) are both convex, and the radius of curvature of the first surface (67a) is greater than the radius of curvature of the second surface (67b).

10. An ultraviolet irradiation device according to claim 9, wherein the first surface (67a) and the second surface (67b) are each an even-order aspherical surface.

11. An air conditioner comprising: a casing (31) having an inlet (32) for drawing in air, an outlet (33) for blowing out air, and an air flow path (34) extending from the inlet (32) to the outlet (33); and an ultraviolet irradiation device (60) for irradiating ultraviolet rays into a treatment space (R) in part of the air flow path (34), wherein the ultraviolet irradiation device (60) is an ultraviolet irradiation device (60) as defined in any one of claims 1 to 10.

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