Light irradiation device

Abstract

To provide a light irradiation device that can suppress increase in current consumption and rise in temperature of an internal element at the time of startup with a simple configuration.SOLUTION: A light irradiation device includes: a light source for emitting light; a fan for delivering air; and a control unit for controlling the light source and the fan to operate and delaying the timing of startup of the fan from the timing of startup of the light source.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a light irradiation device.

Background Art

[0002] There is a light irradiation device including a light source that irradiates light and a fan that sends air. The light irradiation device is used, for example, as an air purifier that sterilizes air while circulating the air in a room or the like. The fan takes in air inside a housing portion that houses the fan and the light source, and discharges the taken-in air to the outside of the housing portion. The light source sterilizes the air by irradiating ultraviolet light onto the air taken into the housing portion. Thereby, the air sterilized by the light irradiated from the light source is discharged to the outside of the housing portion, and the air in a room or the like can be sterilized while circulating the air.

[0003] Further, the light irradiation device may be used, for example, as a lighting device. The light source irradiates light toward a room or the like. The fan cools the light source, internal circuits, and the like by sending air (cooling air) toward the light source, internal circuits, and the like.

[0004] As described above, in a light irradiation device including a light source and a fan, the current consumption may increase or the temperature of internal elements may rise at startup. For this reason, it is necessary to select elements that can withstand the current consumption at startup and take measures such as heat dissipation, and such measures are one of the factors contributing to the increase in the size of the device and the manufacturing cost. Therefore, in a light irradiation device including a light source and a fan, it is desirable to be able to suppress an increase in current consumption and a rise in the temperature of internal elements with a simple configuration at startup.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] Embodiments of the present invention provide a light irradiation device that can suppress an increase in current consumption during startup and a rise in the temperature of internal elements with a simple configuration. [Means for solving the problem]

[0007] According to an embodiment of the present invention, a light source for irradiating light, a fan for blowing air, and a control unit that controls the operation of the light source and the fan, and shifts the timing of the fan's startup from the timing of the light source's startup, A fan power supply that operates the fan by supplying power to the fan, and a switching element provided between the fan and the fan power supply that switches between supplying power to the fan and stopping the power supply, Equipped with, The control unit is connected to the switching element and controls the operation of the switching element to control the switching between supplying power to the fan and stopping the power supply to the fan. When the control unit is not running, the switching element is in a state where the power supply to the fan is stopped. The control unit controls the airflow of the fan by changing the control signal input to the fan, so that the airflow of the fan increases in stages when the fan is started. When the fan is started, after inputting the control signal to the fan, the operation of the switching element is controlled and power is started to be supplied to the fan. A light irradiation device is provided, characterized in that the fan is started while the control signal is input to the fan. [Effects of the Invention]

[0008] According to embodiments of the present invention, a light irradiation device can be provided that can suppress an increase in current consumption during startup and a rise in the temperature of internal elements with a simple configuration. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic block diagram showing a light irradiation device according to the embodiment. [Figure 2] This graph schematically illustrates an example of the operation of the light irradiation device according to the embodiment. [Figure 3] This is a schematic block diagram showing a modified example of the light irradiation device according to the embodiment. [Modes for carrying out the invention]

[0010] Each embodiment will be described below with reference to the drawings. Please note that the drawings are schematic or conceptual, and the relationships between the thickness and width of each part, as well as the ratios of the sizes of the parts, are not necessarily identical to those of reality. Furthermore, even when representing the same part, the dimensions and ratios may differ between drawings. In this specification and in each figure, elements similar to those described above are denoted by the same reference numerals, and detailed explanations are omitted as appropriate.

[0011] Figure 1 is a schematic block diagram showing a light irradiation device according to an embodiment. As shown in Figure 1, the light irradiation device 10 comprises a light source 12 for irradiating light, a fan 14 for circulating air, and a control unit 16 for controlling the operation of the light source 12 and the fan 14. The light irradiation device 10 is, for example, an air purifier that disinfects the air while circulating the air in a room. The following explanation will use the case where the light irradiation device 10 is an air purifier as an example.

[0012] The light irradiation device 10 further comprises a housing 18 that houses the light source 12 and the fan 14. The housing 18 houses, for example, the light source 12 and the fan 14, as well as other parts of the light irradiation device 10, such as a control unit 16. However, the control unit 16 may be provided separately from the housing 18 that houses the light source 12 and the fan 14, and may be configured to control the operation of the light source 12 and the fan 14 by communicating with the equipment inside the housing 18 via wired communication or wireless communication. The configuration of the housing 18 may be any configuration that houses at least the light source 12 and the fan 14. The configuration of the control unit 16 may be any configuration that can control the operation of the light source 12 and the fan 14.

[0013] The fan 14 draws air into the housing 18 and discharges the air drawn into the housing 18 to the outside. The light source 12 irradiates the air drawn into the housing 18 with ultraviolet light to sterilize the air, thereby sterilizing the air while circulating it. As a result, the light irradiation device 10 can sterilize the air while circulating the air in a room or other environment.

[0014] The light source 12 is, for example, a light-emitting diode (LED) capable of emitting ultraviolet light. The light source 12 may also be other light-emitting elements capable of emitting ultraviolet light, or a lamp capable of emitting ultraviolet light, such as a germicidal lamp. The light emitted by the light source 12 may further contain components other than ultraviolet light, such as blue light. The light source 12 may be any light source capable of emitting light that includes at least ultraviolet light. Ultraviolet light is, for example, light with a wavelength of 10 nm to 400 nm.

[0015] Fan 14 operates on a DC power supply, for example. Fan 14 is a DC fan whose airflow can be adjusted by the duty cycle of a PWM signal. However, fan 14 may also be an AC fan that operates on an AC power supply, for example. The configuration of fan 14 can be any configuration that can secure the airflow necessary to properly circulate the air in a room or the like.

[0016] The light irradiation device 10 further includes, for example, a power supply 20 for the light source, a power supply 22 for the fan, and a switching element 24.

[0017] The power supply 20 for the light source is connected to, for example, an AC power supply 2 and receives AC power from the AC power supply 2. The AC power supply 2 is, for example, a commercial power supply. The power supply 20 for the light source converts the AC power supplied from the AC power supply 2 into power corresponding to the light source 12, and lights up the light source 12 by supplying the converted power to the light source 12. For example, if the light source 12 is an LED capable of emitting ultraviolet light, the power supply 20 for the light source converts the AC power supplied from the AC power supply 2 into DC power, and lights up the light source 12 by supplying the DC power to the light source 12. Note that the power supplied to the power supply 20 for the light source is not limited to AC power, but may also be DC power, etc.

[0018] The control unit 16 is connected to the light source power supply 20. The control unit 16 controls the operation of the light source 12 by controlling the operation of the light source power supply 20. In other words, the control unit 16 controls the switching between lighting and extinguishing of the light source 12 by controlling the supply of power from the light source power supply 20 to the light source 12. Further, the control unit 16 controls the intensity (brightness) of the light emitted from the light source 12 by controlling the magnitude of the power supplied from the light source power supply 20 to the light source 12. The light source power supply 20 supplies, for example, PWM-controlled DC power to the light source 12. The control unit 16 controls the intensity of the light emitted from the light source 12 by controlling the duty ratio of the DC power supplied from the light source power supply 20 to the light source 12.

[0019] However, the configuration for controlling the operation of the light source 12 by the control unit 16 is not limited to the above. For example, a switching element may be provided between the light source power supply 20 and the light source 12 or between the light source power supply 20 and the AC power supply 2, and the supply and stop of power from the light source power supply 20 to the light source 12 may be switched by the switching element to control the operation (switching between lighting and extinguishing) of the light source 12. The control unit 16 does not necessarily have to control the intensity of the light emitted from the light source 12. The configuration for controlling the operation of the light source 12 by the control unit 16 may be any configuration that can at least control the switching between lighting and extinguishing of the light source 12.

[0020] The fan power supply 22 is connected to, for example, the AC power supply 2 and receives supply of AC power from the AC power supply 2. The fan power supply 22 operates the fan 14 by converting the AC power supplied from the AC power supply 2 into power corresponding to the fan 14 and supplying the converted power to the fan 14. For example, when the fan 14 is a DC fan, the fan power supply 22 operates the fan 14 by converting the AC power supplied from the AC power supply 2 into DC power and supplying the DC power to the fan 14. Note that the power supplied to the fan power supply 22 is not limited to AC power and may be DC power or the like.

[0021] The switching element 24 is provided between the fan 14 and the fan power supply 22, and switches the supply of power to the fan 14 and the stop of the power supply. The switching element 24 is, for example, a relay. The switching element 24 may also be a semiconductor switch such as a transistor. The switching element 24 may be any element capable of switching the supply of power to the fan 14 and the stop of the power supply.

[0022] The control unit 16 is connected to the switching element 24. The control unit 16 controls the operation of the fan 14 by controlling the operation of the switching element 24. In other words, the control unit 16 controls the switching of the driving and stopping of the fan 14 by controlling the supply of power from the fan power supply 22 to the fan 14 by the switching of the switching element 24.

[0023] Also, the control unit 16 is connected to the fan 14. The control unit 16 controls the supply of power to the fan 14 by the switching of the switching element 24 and controls the air volume (the amount of air sent) of the fan 14 by inputting a control signal to the fan 14. The control signal is, for example, a PWM signal. The control unit 16 controls the air volume of the fan 14 by controlling the duty ratio of the control signal input to the fan 14.

[0024] However, the configuration for controlling the operation of the fan 14 by the control unit 16 is not limited to the above. For example, a switching element may be provided between the fan power supply 22 and the AC power supply 2, and the operation of the fan 14 may be controlled by switching the supply of power from the fan power supply 22 to the fan 14 and the stop of the power supply by the switching element. Alternatively, the operation of the fan power supply 22 may be controlled by the control unit 16, and the operation of the fan 14 may be controlled by switching the supply of power from the fan power supply 22 to the fan 14 and the stop of the power supply.

[0025] In this example, the airflow of the fan 14 is controlled by inputting a control signal from the control unit 16 to the fan 14. However, the airflow of the fan 14 may also be controlled by, for example, controlling the amount of power supplied to the fan 14 from the fan power supply 22. However, the control unit 16 does not necessarily have to control the airflow of the fan 14. The configuration in which the control unit 16 controls the operation of the fan 14 may be any configuration that can control at least the operation of the fan 14 and the switching of its operation to stop.

[0026] Figure 2 is a graph schematically illustrating an example of the operation of the light irradiation device according to the embodiment. Figure 2 schematically shows an example of the DC power voltage Vd output from the fan power supply 22, the control signal Sc input from the control unit 16 to the fan 14, the current If flowing through the fan 14, and the current Ir flowing through the light source 12. Figure 2 schematically shows an example of the operation of the light irradiation device 10 when it is started up. In other words, Figure 2 schematically shows an example of the voltage Vd, control signal Sc, current If, and current Ir when the light irradiation device 10 is started up.

[0027] As shown in Figure 2, when the light irradiation device 10 is started, the fan power supply 22 starts first, and DC power is output from the fan power supply 22. In this state, the switching element 24 is in the open state (off state), and the fan 14 remains stopped. Also, immediately after the light irradiation device 10 is started, the light source power supply 20 has stopped supplying power to the light source 12, and the light source 12 remains off.

[0028] When the light irradiation device 10 is started, the light source 12 is turned off and the fan 14 is stopped, and the control unit 16 starts up. The order in which the control unit 16 starts up and the fan power supply 22 starts up does not matter. When the control unit 16 starts up, it inputs a control signal Sc to the fan 14. After this, the control unit 16 switches the switching element 24 from the open state to the closed state (on state), thereby supplying DC power output from the fan power supply 22 to the fan 14 and starting the fan 14.

[0029] When the fan 14 receives power from the fan power supply 22, it starts operating at an airflow rate corresponding to the control signal Sc input from the control unit 16. In this case, by starting the power supply from the fan power supply 22 while the control signal Sc is input, as described above, it is possible to prevent the fan 14 from starting in an unstable state without the input of the control signal Sc. For example, it is possible to prevent the fan 14 from operating at maximum airflow when starting up due to a delay in the input of the control signal.

[0030] As shown in Figure 2, the control unit 16 shifts the timing of the fan 14's startup from the timing of the light source 12's startup. For example, the control unit 16 starts the other of the light source 12 and fan 14 after the peak of the current flowing when one of them starts up.

[0031] For example, after starting one of the light source 12 and the fan 14, the control unit 16 starts the other of the light source 12 and the fan 14 after the current flowing through one of them reaches a target current value.

[0032] If the light irradiation device 10 is an air purifier, the control unit 16 starts the light source 12 after starting the fan 14. The control unit 16 starts the light source 12 after the peak of the current flowing when the fan 14 starts. This allows, for example, the air sterilization by the light source 12 to begin while the air circulation by the fan 14 is stable. For example, it is possible to prevent the light source 12 from being turned on unnecessarily when air has not been drawn into the housing 18 by the fan 14. However, conversely, the control unit 16 may start the fan 14 after starting the light source 12.

[0033] Furthermore, the control unit 16 controls the airflow of the fan 14 so that the airflow of the fan 14 increases in stages when the fan 14 is started. The control unit 16 controls the airflow of the fan 14 so that the airflow of the fan 14 increases in stages when the fan 14 is started by changing the control signal Sc input to the fan 14, for example.

[0034] Figure 2 shows an example where the control signal Sc input to fan 14 is a PWM signal, and when operating fan 14 at 75% of its maximum airflow (75% duty cycle), the airflow is first set to 25%, then to 50%, and finally to 75%. In Figure 2, the airflow of fan 14 is controlled so that it increases in three stages when fan 14 is started. However, the number of stages in which the airflow is set when fan 14 is started is not limited to three, but can be any number.

[0035] For example, when controlling the airflow of fan 14 by controlling the amount of power supplied to fan 14 from fan power supply 22, the control unit 16 controls the operation of fan power supply 22 to gradually increase the airflow of fan 14 when fan 14 starts up. The configuration for controlling the airflow of fan 14 so that the airflow of fan 14 gradually increases when fan 14 starts up is not limited to the above, and any configuration that can appropriately control the airflow of fan 14 is acceptable.

[0036] When the fan 14 is started, the control unit 16 gradually increases the airflow of the fan 14 toward a preset airflow. The number of steps in which the airflow is set when the fan 14 is started may vary, for example, according to the preset airflow. For example, as shown in Figure 2, if the amount of change in airflow is 25% and the preset airflow is 75%, the airflow of the fan 14 is changed in 3 steps, and if the preset airflow is 100%, the airflow of the fan 14 is changed in 4 steps. Thus, the larger the preset airflow, the more steps in which the airflow is set when the fan 14 is started may be used. The airflow of the fan 14 may be arbitrarily set by the control unit 16, for example, by operating an operation unit (not shown in the figure).

[0037] In a light irradiation device 10 equipped with a light source 12 and a fan 14, the current consumption may increase and the temperature of internal components may rise during startup. The inventors of this application have found that, as a result of their investigation, this increase in current consumption and temperature rise of internal components during startup is due to the relatively large currents that flow when the light source 12 and fan 14 are started, as shown in Figure 2. In particular, when the timing of starting the light source 12 and the timing of starting the fan 14 overlap, and the starting currents of the light source 12 and the fan 14 flow simultaneously, the increase in current consumption and temperature rise of internal components during startup become significant.

[0038] In contrast, in the light irradiation device 10 according to this embodiment, the control unit 16 shifts the timing of the fan 14's startup from the timing of the light source 12's startup. This suppresses the simultaneous flow of the starting current of the light source 12 and the fan 14, thereby suppressing an increase in current consumption during startup and a rise in the temperature of the internal elements.

[0039] In the light irradiation device 10 according to this embodiment, there is no need to provide special components to address the increase in current consumption during startup or the rise in temperature of internal elements. By shifting the startup timing of the fan 14 to the startup timing of the light source 12, it is possible to suppress the increase in current consumption during startup and the rise in temperature of internal elements with a simple configuration. Furthermore, this reduces the need to select elements that can withstand high current consumption or to add components for heat dissipation, thereby suppressing the increase in device size and manufacturing costs associated with these measures.

[0040] Furthermore, in the light irradiation device 10 according to this embodiment, the control unit 16 starts the other of the light source 12 and the fan 14 after the peak of the current flowing when one of them starts up. This makes it possible to more effectively suppress the simultaneous flow of the starting current of the light source 12 and the starting current of the fan 14. Consequently, it is possible to more effectively suppress the increase in current consumption during startup and the rise in temperature of the internal elements.

[0041] For example, after starting one of the light source 12 and the fan 14, the control unit 16 starts the other light source 12 and the fan 14 after the current flowing through one of them has decreased from a large starting current value to a target current value. This allows for more effective suppression of the simultaneous flow of the starting current of the light source 12 and the starting current of the fan 14. This allows for more effective suppression of increased current consumption during startup and the rise in temperature of internal components.

[0042] Furthermore, the control unit 16 controls the airflow of the fan 14 so that the airflow of the fan 14 increases in stages when the fan 14 is started. This prevents, for example, the fan 14 from deteriorating prematurely due to sudden operation. Also, for example, it prevents the fan 14 from making loud noises when it starts up due to sudden operation.

[0043] Figure 3 is a schematic block diagram showing a modified example of the light irradiation device according to the embodiment. As shown in Figure 3, the light irradiation device 10a is equipped with multiple fans 14. Components that are substantially the same in function and configuration as those in the above embodiment are denoted by the same reference numerals, and detailed descriptions are omitted.

[0044] The light irradiation device 10a further includes, for example, a plurality of switching elements 24. The control unit 16 is connected to the plurality of switching elements 24. The control unit 16 controls the operation of each of the plurality of fans 14 by controlling the operation of each of the plurality of switching elements 24. In other words, the control unit 16 individually controls the switching of the plurality of fans 14 by controlling the supply of power from the fan power supply 22 to each of the plurality of fans 14 through the switching of each of the plurality of switching elements 24.

[0045] Furthermore, the control unit 16 is connected to multiple fans 14. The control unit 16 controls the power supply to the multiple fans 14 by switching multiple switching elements 24, and controls the airflow of each of the multiple fans 14 by inputting control signals to each of the multiple fans 14.

[0046] However, the configuration in which the control unit 16 controls the operation of each of the multiple fans 14, similar to the embodiment described above, is not limited to the above.

[0047] In the light irradiation device 10a, the control unit 16 further staggers the starting timing of each of the multiple fans 14. The light irradiation device 10a is equipped with two fans 14. The control unit 16 starts one fan 14, and then starts the other fan 14. For example, the control unit 16 starts the other fan 14 after the peak of the current flowing when the first fan 14 starts.

[0048] The control unit 16 starts the light source 12 after the multiple fans 14 have started, or before the multiple fans 14 have started. The control unit 16 may, for example, start the light source 12 between the start of one fan 14 and the start of the other fan 14. The timing of starting the light source 12 can be any timing that does not overlap with the start timing of each of the multiple fans 14.

[0049] As a result, even when the light irradiation device 10a is equipped with multiple fans 14, it is possible to suppress the simultaneous flow of starting currents for multiple fans 14. Therefore, even when multiple fans 14 are equipped, the increase in current consumption during startup and the rise in temperature of internal elements can be suppressed more effectively.

[0050] Although the light irradiation device 10a is shown as an example with two fans 14, the number of fans 14 is not limited to two; there may be three or more. The control unit 16 should control the operation of the light source 12 and the multiple fans 14 so that their respective start-up timings do not overlap.

[0051] In the above embodiments, the case where the light irradiation device is an air purifier was described. However, the light irradiation device is not limited to an air purifier. The light irradiation device may be, for example, a lighting device. The light source may be a light source that irradiates light towards a room or the like. The fan may be a fan that cools the light source and internal circuits by sending air (cooling air) towards the light source and the power supply for the light source. For example, in light irradiation devices that irradiate laser light or light irradiation devices that irradiate relatively strong light for outdoor performances, fans may be used to cool the light source and internal circuits. The configurations of the above embodiments may be applied to such light irradiation devices.

[0052] The light irradiation device may be any light irradiation device that includes at least a light source, a fan, and a control unit, and the timing of the fan's startup is staggered from the timing of the light source's startup.

[0053] While several embodiments and examples of the present invention have been described, these embodiments or examples are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments or examples can be carried out in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments or examples and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0054] 2…AC power supply, 10, 10a…Light irradiation device, 12…Light source, 14…Fan, 16…Control unit, 18…Housing, 20…Power supply for light source, 22…Power supply for fan, 24…Switching element

Claims

1. A light source that emits light, A fan to blow air, A control unit that controls the operation of the light source and the fan, and shifts the timing of the fan's startup from the timing of the light source's startup, A fan power supply that operates the fan by supplying power to the fan, A switching element is provided between the fan and the power supply for the fan, which switches between supplying power to the fan and stopping the power supply. Equipped with, The control unit is connected to the switching element and controls the operation of the switching element, thereby controlling the switching between supplying power to the fan and stopping the supply of power to the fan. When the control unit is not running, the switching element will be in a state where the power supply to the fan is stopped. The light irradiation device is characterized in that the control unit controls the airflow of the fan by changing the control signal input to the fan so that the airflow of the fan increases in stages when the fan is started, and after inputting the control signal to the fan when the fan is started, controls the operation of the switching element and starts supplying power to the fan, thereby starting the fan while the control signal has been input to the fan.

2. The light irradiation apparatus according to claim 1, characterized in that the control unit starts the other light source and the fan after the peak of the current flowing when one of the light source and the fan is started.

3. Equipped with multiple of the aforementioned fans, The light irradiation device according to claim 1 or 2, characterized in that the control unit further staggers the starting timing of each of the multiple fans.

4. The system further comprises a housing that houses the light source and the fan inside, The fan draws air into the housing and discharges the air drawn into the housing to the outside of the housing. The light irradiation device according to any one of claims 1 to 3, characterized in that the light source irradiates ultraviolet light onto the air taken into the housing and sterilizes the air, thereby sterilizing the air while circulating it.

5. The light irradiation device according to any one of claims 1 to 4, characterized in that the control unit starts the light source after starting the fan.

6. The light irradiation device according to any one of claims 1 to 4, characterized in that the control unit starts the fan after starting the light source.

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