Ultraviolet LED irradiation device

Abstract

To provide an ultraviolet LED irradiation device that, in LEDs connected in series on an electric circuit, can specify a disconnected portion by lighting of individual ultraviolet LEDs.SOLUTION: An ultraviolet LED irradiation device 1 comprises an electric circuit 2 for individually lighting up ultraviolet LEDs. The electric circuit 2 is provided with a serial unit 4 that connects the ultraviolet LEDs 11, 12, 13, 14 in series, a first circuit 5, and a second circuit 6, and is further provided with a bypass circuit. The bypass circuit is provided with a first switch and a second switch. In normal operation, only a switch 40 is turned on. In LED check operation, only the first switch 31 and the second switch 41 are turned on, and the other switches are turned off in, for example, checking the ultraviolet LED 11.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an ultraviolet LED irradiation device used in fluorescent magnetic particle testing and fluorescent penetrant testing. [Background technology]

[0002] In the fields of fluorescent magnetic particle testing and fluorescent penetrant testing, metal halide lamps combined with reflectors have traditionally been used, but due to concerns over their high power consumption and the environmental impact of using mercury, there has been a shift to UV LEDs. Although UV LEDs have become increasingly powerful in recent years, their intensity and irradiation range as a single unit still do not match that of conventional metal halide lamps, so UV LED irradiation devices are used that combine multiple UV LEDs (light sources) to achieve the desired UV intensity within the range of the irradiation surface set at a specified distance.

[0003] Also, LED circuits can be in series, parallel, or a combination of series and parallel, and are designed by designers depending on the application and the environment of the equipment. In the case of a series circuit, the circuit is simple. It has the advantage that the current value is constant and it is easy to adjust the brightness, but it has the disadvantage that it is not possible to adjust individually to the variations in the LED elements, and if an LED element breaks / shorts (fails), it affects all of the same circuit. On the other hand, when a parallel circuit is used, it has the advantage that it is easy to identify the failed LED element and adjust each LED element individually, but it has the disadvantage that a control circuit is required for each LED element, which tends to be complex and expensive, and that individual adjustments must be made to match the intensity (current) due to variations in the internal resistance of the LED elements.

[0004] When the circuit of the LED element is broken or shorted, the ultraviolet LED must be replaced. Therefore, it is necessary to identify the ultraviolet LED in question, but since fluorescent magnetic particle testing and fluorescent penetrant testing are often performed in dark places, there are cases where visible light lighting is provided, but generally there is not enough light and the work place is a dark room with a small space. Therefore, maintenance of the ultraviolet LED irradiation device is usually difficult.

[0005] Conventionally, when using an ultraviolet LED irradiation device, if a short circuit or break occurs, the ultraviolet LED is replaced. This is done in a narrow darkroom, and it is necessary to check whether ultraviolet light is being irradiated, which results in a very heavy workload. If a short circuit occurs in a series circuit, the load on the circuit is reduced, so the normal LED elements in the same circuit are burdened. If the power to the circuit is not immediately cut off, in the worst case scenario, all LED elements in the same circuit may be damaged. Therefore, it is necessary to configure a circuit that detects a short circuit and cuts off the power. Also, if a wire breaks in a series circuit, all LED elements in the same circuit will go out. In other words, in the case of a series circuit, all LED elements in the circuit will go out whether there is a short circuit or a break. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2014-72501 A Summary of the Invention [Problem to be solved by the invention]

[0007] Patent Document 1 discloses an LED module in which, when driving LED elements with a full-wave rectified waveform, even if light-emitting circuit blocks including LED strings and current detection resistors are connected in multiple stages, the value of the current detection resistor is set to a reference value R, and the current detection values ​​included in each light-emitting circuit block are set to 2R, 3R, and 4R. This is intended to reduce the management burden of the current detection resistors, and to make it easier to identify the location of a break by providing a detection bypass circuit in the LED series circuit, but it identifies the break by the resistance value, and is not possible to identify it during actual lighting.

[0008] Since work is done in a dark place, the issue has been whether it is possible to detect a break in the light without using measuring equipment. Also, when LEDs are connected in parallel, slight differences in the thickness of the board can cause variations in the intensity of the UV light emitted, which can easily cause problems in flaw detection testing. As such, it is difficult to make the light intensity uniform when connected in parallel, but it is easier to make the light intensity uniform when connected in series, so it is desirable to configure the LEDs as a circuit connected in series. However, when a series circuit is used, if a problem such as a break occurs in one of the LEDs, all the LEDs will turn off.

[0009] In addition, when testing with actual lighting, the ultraviolet light used in fluorescent magnetic particle testing and fluorescent penetrant testing is required to have a high energy intensity of 1000μW / cm^2 or more on the test surface according to JIS Z2323 and other standards. However, ultraviolet light is harmful to the eyes when viewed directly, and the risk is even higher when viewed directly in a dark place with dilated pupils. In this state, if an LED in an ultraviolet LED irradiation device using a series circuit breaks, all LEDs in the series circuit will turn off, making it difficult to identify the broken LED. In this case, in order to identify the broken LED, it was necessary to attach an LED whose soundness was confirmed or check each one with a tester. Since testers are generally not available at the inspection site, LEDs whose soundness was confirmed are often installed and checked. However, in a poor environment such as a dark place and a narrow space, the task of identifying the broken LED by repeating trial and error for each LED in the series circuit was a very heavy task. In addition, there was a risk that workers would mistakenly look directly at the high-intensity ultraviolet light to check the lighting status of the ultraviolet LEDs, and these points were issues.

[0010] In order to solve the above problems, the present invention aims to provide an ultraviolet LED irradiation device consisting of ultraviolet LEDs connected in series, which is an ultraviolet LED irradiation device that can easily identify a faulty LED in a series circuit when actually turned on, and which makes it possible to avoid looking directly at high-intensity ultraviolet light when inspecting the ultraviolet LEDs to detect breaks when actually turned on. [Means for solving the problem]

[0011] In the ultraviolet LED irradiation device of the present invention, an ultraviolet LED irradiation device for flaw detection equipped with a plurality of ultraviolet LEDs is characterized in that the ultraviolet LED irradiation device is equipped with an electrical circuit for turning on the ultraviolet LEDs, the plurality of ultraviolet LEDs are each connected in series on the electrical circuit, the plurality of ultraviolet LEDs are configured to be individually replaceable, and the electrical circuit is equipped with one or more bypass circuits that can turn on the plurality of ultraviolet LEDs individually.

[0012] Furthermore, the ultraviolet LED irradiation device of the present invention is characterized in that the electrical circuit includes a series section in which the ultraviolet LEDs are connected in series, the series section further includes a first limiting resistor, and the bypass circuit includes a second limiting resistor, the second limiting resistor having an electrical resistance greater than that of the first limiting resistor.

[0013] In addition, the ultraviolet LED irradiation device of the present invention is characterized in that the electric circuit is composed of a power source, a series section in which the ultraviolet LEDs are connected in series, a first circuit connecting the power source to the series section, a second circuit connecting the series section to the power source, and the bypass circuit, the bypass circuit is composed of a first bypass circuit and a second bypass circuit, the first bypass circuit has a first switch, the second bypass circuit has a second switch, the series section has a second connection section between the ultraviolet LEDs connected in series, the second connection section is connected to the first bypass circuit and the second bypass circuit, the first bypass circuit is connected to the first circuit via a first connection section, and the second bypass circuit is connected to the second circuit via a fourth connection section, and the electric circuit controls the on / off of the first switch and the second switch, so that the ultraviolet LEDs can be individually turned on.

[0014] Furthermore, the ultraviolet LED irradiation device of the present invention is characterized in that the ultraviolet LED irradiation device further comprises a case and a lid, and is configured so that the ultraviolet LEDs can be inspected by opening the lid, and the ultraviolet LED irradiation device further comprises a sensor and a control unit that detects the opening and closing of the lid, and the control unit is configured to be able to control the on / off of a switch, the first switch and the second switch so as to perform a normal operating operation when the lid is closed, and to perform an LED check operation when the lid is open.

[0015] In addition, in the present invention, the ultraviolet LED irradiation device further comprises a case and a lid, and the inside surface of the lid is provided with a fluorescent member that emits light when irradiated with ultraviolet light. Effect of the Invention

[0016] In the ultraviolet LED irradiation device of the present invention, an ultraviolet LED irradiation device for flaw detection equipped with a plurality of ultraviolet LEDs is provided with an electrical circuit for turning on the ultraviolet LEDs, each of the plurality of ultraviolet LEDs is connected in series on the electrical circuit, each of the plurality of ultraviolet LEDs is configured to be individually replaceable, and the electrical circuit is characterized in having one or more bypass circuits that can turn on the plurality of ultraviolet LEDs individually.Therefore, an ultraviolet LED irradiation device can be provided in which, if an ultraviolet LED fails to light, it is easy to identify which LED has the defect and replace it.

[0017] Furthermore, the ultraviolet LED irradiation device of the present invention is characterized in that the electrical circuit includes a series section in which the ultraviolet LEDs are connected in series, the series section further includes a first limiting resistor, and the bypass circuit includes a second limiting resistor, the second limiting resistor having an electrical resistance greater than the first limiting resistor. Therefore, it is possible to provide an ultraviolet LED irradiation device that can prevent the danger of an operator accidentally looking directly at high-intensity ultraviolet light when visually checking the lighting status of the ultraviolet LEDs.

[0018] In addition, the ultraviolet LED irradiation device of the present invention is characterized in that the electric circuit is composed of a power source, a series section in which multiple ultraviolet LEDs are connected in series, a first circuit connecting the power source to the series section, a second circuit connecting the series section to the power source, and a bypass circuit, the bypass circuit is composed of a first bypass circuit and a second bypass circuit, the first bypass circuit has a first switch, the second bypass circuit has a second switch, the series section has a second connection section between the multiple ultraviolet LEDs connected in series, the second connection section is connected to the first bypass circuit and the second bypass circuit, the first bypass circuit is connected to the first circuit via the first connection section, and the second bypass circuit is connected to the second circuit via a fourth connection section, and the electric circuit is configured to control the on / off of the first switch and the second switch so that the multiple ultraviolet LEDs can be individually turned on. Therefore, an ultraviolet LED irradiation device can be provided in which, when an ultraviolet LED fails to light, it is easy to identify which LED has the failure and replace it.

[0019] Furthermore, the ultraviolet LED irradiation device of the present invention is characterized in that the ultraviolet LED irradiation device further comprises a case and a lid, and is configured so that the ultraviolet LEDs can be inspected by opening the lid, and the ultraviolet LED irradiation device further comprises a sensor and a control unit which detects the opening and closing of the lid, and the control unit is configured so as to be able to control the on / off of the switch, the first switch and the second switch so as to perform a normal operating operation when the lid is closed, and to perform an LED check operation when the lid is open. Thus, an ultraviolet LED irradiation device can be provided which can prevent the danger of an operator accidentally looking directly at high-intensity ultraviolet light when visually checking the lighting state of the ultraviolet LEDs.

[0020] Furthermore, the ultraviolet LED irradiation device of the present invention is characterized in that the ultraviolet LED irradiation device further comprises a case and a lid, and the inner surface of the lid is provided with a fluorescent member that emits light when irradiated with ultraviolet light. Therefore, even with weak ultraviolet light intensity, the status of the LED can be indirectly checked from the light emission state of the fluorescent member, and an ultraviolet LED irradiation device can be provided that prevents the danger of an operator accidentally looking directly at high-intensity ultraviolet light. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view showing an ultraviolet LED irradiation device 1 according to an embodiment of the present invention. [Diagram 2] 2 is a perspective view showing the ultraviolet LED irradiation device 1 according to the present embodiment with the lid 52 in an open state. FIG. [Diagram 3] As an example of this embodiment, an electric circuit 2 provided in an ultraviolet LED irradiation device 1 is illustrated in a circuit diagram. [Figure 4] FIG. 1 is a circuit diagram showing an electric circuit 2′ of an ultraviolet LED irradiation device 1 as another example of this embodiment. [Diagram 5] FIG. 2 is a circuit diagram showing an electric circuit 2 during normal operation. [Figure 6] 1 is a circuit diagram showing a state where the operation of the ultraviolet LED 11 is checked during an LED check operation in the electric circuit 2. FIG. [Figure 7] 1 is a circuit diagram showing a state where the operation of the ultraviolet LED 12 is checked during an LED check operation in the electric circuit 2. FIG. [Figure 8] 13 is a circuit diagram showing a state where the operation of the ultraviolet LED 13 is checked during an LED check operation in the electric circuit 2. FIG. [Figure 9] 13 is a circuit diagram showing a state where the operation of the ultraviolet LED 14 is checked during an LED check operation in the electric circuit 2. FIG. [Figure 10] As another example of this embodiment, an electric circuit 102 provided in the ultraviolet LED irradiation device 1 is illustrated in a circuit diagram. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, the details of the embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an ultraviolet LED irradiation device 1 according to this embodiment, and is a perspective view seen from below when the lid is in a closed state during normal operation. FIG. 2 is a perspective view showing the ultraviolet LED irradiation device 1 shown in FIG. 1 from diagonally below, and illustrates when the lid 52 is in an open state. FIG. 3 is a circuit diagram showing an electric circuit 2 as an example used in the ultraviolet LED irradiation device 1. FIG. 4 is a circuit diagram showing an electric circuit 2' used in the ultraviolet LED irradiation device 1, which is another example of the electric circuit 2 shown in FIG. 3. FIG. 5 is a diagram showing the current flow during normal operation of the electric circuit 2. FIG. 6 is a circuit diagram showing the current flow during an LED check operation for checking the ultraviolet LED 11 of the electric circuit 2. FIG. 7 is a circuit diagram showing the current flow during an LED check operation for checking the ultraviolet LED 12 of the electric circuit 2. FIG. 8 is a circuit diagram showing the current flow during an LED check operation for checking the ultraviolet LED 13 of the electric circuit 2. Fig. 9 is a circuit diagram showing the current flow during the LED check operation for checking the ultraviolet LEDs 14 of the electric circuit 2. Fig. 10 is a circuit diagram showing an electric circuit 102 as another example used in the ultraviolet LED irradiation device 1 of this embodiment.

[0023] Next, an embodiment of the ultraviolet irradiation device 1 of the present invention will be described with reference to FIG. 1. The ultraviolet LED irradiation device 1 of the present invention includes a case 54 in which a plurality of ultraviolet LEDs are stored, a lid 52, an ultraviolet irradiation unit 53, and fixtures 50 and 51 for fixing to a ceiling or the like. As shown in FIG. 2, the lid 52 can be opened, and is in a closed state in FIG. 1. When the lid is closed, the device is in normal operation, and FIG. 2 shows the case in which the lid 52 is opened in order for an operator to check the lighting state of the ultraviolet LEDs. The normal operation refers to the case in which the ultraviolet LED irradiation device 1 irradiates an object with ultraviolet light with sufficient intensity to perform a flaw detection test or the like. As shown in FIG. 2, ultraviolet LED storage devices 56, 57, 58, and 59 are stored in the case 54. Each ultraviolet LED storage device stores ultraviolet LEDs connected in series on the electric circuit of the present invention. FIG. 2 illustrates an embodiment in which there are four ultraviolet LEDs, but the number of ultraviolet LEDs is not limited to this.

[0024] Next, the function of the ultraviolet irradiation device 1 of the present invention will be described in more detail with reference to FIG. 2. Each of the ultraviolet LED storage devices 56, 57, 58, and 59 stores an ultraviolet LED, and in the LED check operation of the present disclosure, for example, first only the ultraviolet LED storage device 56 is turned on, then only the ultraviolet LED storage device 57 is turned on, and then only the ultraviolet LED storage device 58 is turned on, and so on. In the LED check operation, only the ultraviolet LED storage devices 56 and 58 are turned on, and then only the ultraviolet LED storage devices 57 and 59 are turned on and then turned off, so that two or more ultraviolet LEDs may be turned on. By performing such an operation, the operator can easily check which ultraviolet LED is defective while comparing it with the irradiation state of the other ultraviolet LEDs. In magnetic particle testing and penetrant testing, defects are detected by irradiating the test object with ultraviolet light. Therefore, when irradiating ultraviolet light using the ultraviolet LED irradiation device 1, it is possible to easily check whether there are any defects in the light distribution range due to breaks or the like, thereby ensuring the detectability of defects in magnetic particle testing and penetrant testing.

[0025] The ultraviolet irradiation device 1 according to the present embodiment will be described in more detail with reference to FIG. 2. The lid 52 is provided with a fluorescent member 55. The fluorescent member 55 is a member that emits a fluorescent color when irradiated with ultraviolet light, and may be a known member such as a fluorescent sheet that emits light when irradiated with ultraviolet light, or a paint that emits light when irradiated with ultraviolet light. By providing the fluorescent member 55, when an operator performs an LED check with the lid 52 open as shown in FIG. 2, even if the ultraviolet light irradiation by the ultraviolet LED in the LED check operation is performed with a weaker ultraviolet light intensity, it is possible to easily check whether the ultraviolet LED is not lit due to a broken electrical circuit or deterioration of the ultraviolet LED.

[0026] The ultraviolet LEDs stored in the ultraviolet LED storage devices 56, 57, 58, and 59 are composed of a single LED (light-emitting diode) or multiple LEDs. Each ultraviolet LED storage device stores ultraviolet LEDs connected on an electric circuit, and the ultraviolet LEDs are connected in series as shown in Figs. 3, 4, and 10, and a bypass circuit is provided. For example, the ultraviolet LED storage device 56 may be configured to store the ultraviolet LED 11, the ultraviolet LED storage device 57 may be configured to store the ultraviolet LED 12, the ultraviolet LED storage device 58 may be configured to store the ultraviolet LED 13, and the ultraviolet LED storage device 59 may be configured to store the ultraviolet LED 14. Of course, the ultraviolet LED storage device 56 may be configured to store the ultraviolet LED 111, the ultraviolet LED storage device 57 may be configured to store the ultraviolet LED 112, the ultraviolet LED storage device 58 may be configured to store the ultraviolet LED 113, and the ultraviolet LED storage device 59 may be configured to store the ultraviolet LED 114.

[0027] Next, referring to FIG. 3, an electric circuit 2 in the case where the ultraviolet LED irradiation device 1 includes the electric circuit 2 is illustrated as an example of the ultraviolet LED irradiation device according to the present embodiment. In the embodiment of FIG. 3, the ultraviolet LED irradiation device 1 includes four ultraviolet LEDs, but is not limited to this, and may include any number of ultraviolet LEDs. The electric circuit 2 includes a series section 4, a first circuit 5, a second circuit 6, and a bypass circuit. The bypass circuit includes a first bypass circuit and a second bypass circuit. As shown in FIG. 3, the series section 4 includes ultraviolet LEDs 14, 13, 12, and 11, a first limiting resistor 20, and a switch 40, in that order, with the one closer to the positive electrode on the electric circuit as the front. The number of ultraviolet LEDs is not limited, and they may be connected in series as shown in FIG. 3, with the one closer to the positive electrode on the electric circuit as the front.

[0028] In addition, the series section 4 includes a second connection section 15 between the ultraviolet LED 14 and the ultraviolet LED 13, a second connection section 16 between the ultraviolet LED 13 and the ultraviolet LED 12, and a second connection section 17 between the ultraviolet LED 12 and the ultraviolet LED 11. However, any number of ultraviolet LEDs can be provided, and when N ultraviolet LEDs are provided in the series section 4, N-1 second connection sections are provided, and second connection sections are provided between all adjacent ultraviolet LEDs connected in series. Furthermore, the series section 4 includes a third connection section 18 after the ultraviolet LED 11 when the one closer to the positive electrode is the front in the electric circuit. In other words, when N ultraviolet LEDs are provided in the series section 4, the third connection section is provided after the Nth ultraviolet LED and before the first limiting resistor 20, counting from the one closer to the positive electrode. Only one third connection section is provided.

[0029] Next, the first circuit 5 in the electric circuit 2 will be described as an example of the ultraviolet LED irradiation device according to the present embodiment. The first circuit 5 includes first connection parts 8, 9, and 10. However, since any number of ultraviolet LEDs can be provided, when N ultraviolet LEDs are provided in the series section 4, N-1 first connection parts are provided. In FIG. 3, the number of ultraviolet LEDs is four, and the number of first connection parts is three. The series section 4 refers to the ultraviolet LED 14, which is the front ultraviolet LED among the ultraviolet LEDs, when the side closer to the positive electrode on the electric circuit is the front, to the switch 40, and the first circuit 5 refers to the part connecting the power source 3 and the ultraviolet LED 14, and refers to the ultraviolet LED 14, which is the front ultraviolet LED among the ultraviolet LEDs, when the side closer to the positive electrode on the electric circuit is the front.

[0030] Next, the first bypass circuit provided in the electric circuit 2, which is an example of the ultraviolet LED irradiation device according to this embodiment, will be described in detail. When N ultraviolet LEDs are provided, N-1 first bypass circuits are provided, and any one of the first connection parts and any one of the second connection parts are connected by a path other than the direct connection between the first circuit 5 and the series part 4. However, the number is not limited to this when two or more ultraviolet LEDs are turned on. In the electric circuit 2, which is an embodiment shown in FIG. 3, the first bypass circuit includes one that connects the first connection part 8 and the second connection part 15, one that connects the first connection part 9 and the second connection part 16, and one that connects the first connection part 10 and the second connection part 17. In other words, the first bypass circuit is a circuit that connects one first connection part and one second connection part. Each first bypass circuit includes first switches 31, 32, and 33. Any of the members constituting the electric circuit 2 in this disclosure, such as the first switch, can be appropriately used.

[0031] Furthermore, the order of the first connection parts 8, 9, 10 in the first circuit 5 is not limited to that shown in the figure, and may be any order, such as 9, 8, 10.

[0032] Next, the second circuit 6 will be described in detail. The second circuit 6 refers to a portion that connects the switch 40 in the series unit 4 to the power source 3, with the end closer to the positive electrode being the front in the electric circuit. The second circuit 6 includes fourth connection portions 45, 46, 47, and 48. When the series unit 4 includes N ultraviolet LEDs, the second circuit 6 includes the same number, N, of fourth connection portions. The order of the fourth connections 45, 46, 47, 48 is not limited to that shown in FIG. 3 and may be any order.

[0033] Next, the second bypass circuit will be described in detail. The second bypass circuit is a circuit that connects any one of the second connection parts 15, 16, 17 or the third connection part 18 to any one of the fourth connection parts 45, 46, 47, 48 via a path different from the circuit that directly connects the series part 4 to the second circuit 6. Each second bypass circuit includes a second limiting resistor and a second switch. As shown in FIG. 3, among the four second bypass circuits, the one that connects the second connection part 15 to the fourth connection part 48 includes a second limiting resistor 24 and a second switch 44. The second bypass circuits that connect the second connection parts 16, 17 to the fourth connection parts 47, 46 and the second bypass circuit that connects the third connection part 18 to the fourth connection part 45 include second switches 43, 42, 41 and second limiting resistors 23, 22, 21, respectively. In the case where the ultraviolet LEDs are turned on one by one, the second bypass circuit is provided with N ultraviolet LEDs in the series section 4 in the electrical circuits 2, 2', but is not limited to this in cases where two or more ultraviolet LEDs are turned on at a time.

[0034] The second connection part may be configured as in the second connection part 15 shown in FIG. 3 , by dividing the first bypass circuit into two parts: a path that connects the first bypass circuit between the ultraviolet LED 14 and the ultraviolet LED 13 in the series part 4, and a path that connects the second bypass circuit between the ultraviolet LED 14 and the ultraviolet LED 13; or the first bypass circuit that connects the first connection part 9 and the second connection part 16 may be connected to the second bypass circuit at the fifth connection part 35, so that the section from the fifth connection part 35 to the second connection part 16 is configured as a shared section in which the first bypass circuit and the second bypass circuit are shared.

[0035] Next, the electric circuit 2' shown in FIG. 4 will be described in detail. The electric circuit 2' shows an electric circuit 2' in the case where the ultraviolet LED irradiation device 1 is provided with the electric circuit 2' as another example of the embodiment of the present invention. The electric circuit 2' is different from the electric circuit 2 in the configuration of the second connection part 15 and in that a fifth connection part 34 is provided. As a result, as shown in FIG. 4, all the first bypass circuits may be connected to the second bypass circuit via the fifth connection part, and a shared part may be provided, or all or a part of the multiple second connection parts may be configured in the same manner as the configuration shown in FIG. 3 in which the second connection part 15 is divided into two parts, that is, a path connecting the first bypass circuit between the ultraviolet LED 14 and the ultraviolet LED 13, and a path connecting the second bypass circuit between the ultraviolet LED 14 and the ultraviolet LED 13.

[0036] Next, the normal operation of the electric circuit 2 will be described in detail with reference to FIG. 5. In the description of the LED check operation during normal operation, the description of the electric circuit 2 is the same for the electric circuit 2' unless otherwise specified. In FIG. 5, only the switch 40 is in the on state, and all other switches are in the off state. In this case, the other switches are the first switches 31, 32, 33 and the second switches 41, 42, 43, 44. Then, the current will preferentially pass through the path indicated by the solid line in FIG. 5, and no current will flow through the path indicated by the dashed line. Then, the current passes through the first circuit 5, electricity flows through the ultraviolet LEDs 14, 13, 12, 11 of the series section 4, the current flows through the first limiting resistor 20, and then the current flows through the second circuit 6. The first limiting resistor 20 is provided so that the ultraviolet LED elements are not damaged, and is configured to have a lower resistance value than the second limiting resistors 21, 22, 23, 24 so that the ultraviolet irradiation has sufficient intensity.

[0037] Next, referring to FIG. 6, the LED check operation of the electric circuit 2, when checking the ultraviolet LED 11, will be described in detail. When checking the ultraviolet LED 11, the first switch 31 and the second switch 41 are in the ON state, and the other switches shown in FIG. 6 are in the OFF state. When checking the ultraviolet LED 11, the current flows in the solid line portion shown in FIG. 6, and the current does not flow in the broken line portion. That is, the current flows through the first circuit 5, the first bypass circuit via the first connection portion 10, the ultraviolet LED 11 via the second connection portion 17, the third bypass circuit via the third connection portion 18, and the second circuit 6 via the fourth connection portion 45. By controlling the switches in this way, only the ultraviolet LED 11 can be turned on, and it is possible to inspect the lighting of the ultraviolet LED 11 and to confirm that there is no disconnection around the ultraviolet LED 11. In the second bypass circuit, the current passes through the second limiting resistor 21, which has a higher resistance value than the first limiting resistor 20 and is configured to have a value that weakens the ultraviolet light intensity to an extent that the LED lighting can be visually confirmed. The same is true for the other second limiting resistors 22, 23, and 24. In addition, the resistance value of the second limiting resistors 21, 22, 23, and 24 is preferably 10 to 1000 times the resistance value of the first limiting resistor. By configuring the resistance value of the second limiting resistors 21, 22, 23, and 24 to be higher than the resistance value of the first limiting resistor in this way, even if ultraviolet light enters the eyes of an operator during the LED check operation, the emission of the ultraviolet LED can be checked and is sufficiently weak, making it easy for the operator to check the LED and reducing the risk, which is preferable.

[0038] Next, referring to FIG. 7, the LED check operation of the electric circuit 2, when checking the ultraviolet LED 12, will be described in detail. When checking the ultraviolet LED 12, the first switch 32 and the second switch 42 are in the ON state, and the other switches shown in FIG. 7 are in the OFF state. When checking the ultraviolet LED 12, the current flows in the solid line portion shown in FIG. 6, and the current does not flow in the broken line portion. That is, the current flows through the first circuit 5, the first bypass circuit via the first connection portion 9, the ultraviolet LED 12 via the second connection portion 16, the second bypass circuit via the second connection portion 17, and the second circuit 6 via the fourth connection portion 46. By controlling the switches in this way, only the ultraviolet LED 12 can be turned on, and it is possible to check whether the ultraviolet LED 12 is turned on and to confirm that there is no disconnection around the ultraviolet LED 12.

[0039] Next, referring to FIG. 8, the LED check operation of the electric circuit 2, when checking the ultraviolet LED 13, will be described in detail. When checking the ultraviolet LED 13, the first switch 33 and the second switch 43 are in the ON state, and the other switches shown in FIG. 8 are in the OFF state. When checking the ultraviolet LED 13, the current flows in the solid line portion shown in FIG. 8, and the current does not flow in the broken line portion. That is, the current flows through the first circuit 5, the first bypass circuit via the first connection portion 8, the ultraviolet LED 13 via the second connection portion 15, the second bypass circuit via the second connection portion 16, and the second circuit 6 via the fourth connection portion 47. By controlling the switches in this way, only the ultraviolet LED 13 can be turned on, and it is possible to inspect the lighting of the ultraviolet LED 13 and to confirm that there is no disconnection around the ultraviolet LED 13.

[0040] Next, referring to FIG. 9, the LED check operation of the electric circuit 2, when checking the ultraviolet LED 14, will be described in detail. When checking the ultraviolet LED 14, the second switch 44 is in an on state, and the other switches shown in FIG. 9 are in an off state. When checking the ultraviolet LED 14, the current flows in the solid line portion shown in FIG. 9, and the current does not flow in the dashed line portion. That is, the current flows through the first circuit 5, enters the serial part 4, flows through the ultraviolet LED 14, passes through the second connection part 15, flows through the second bypass circuit, and flows through the second circuit 6 via the fourth connection part 48. By controlling the switch in this way, only the ultraviolet LED 14 can be turned on, and it is possible to check whether the ultraviolet LED 14 is turned on and to confirm that there is no disconnection around the ultraviolet LED 14.

[0041] Next, referring to FIG. 10, an electric circuit 102 in the case where the ultraviolet LED irradiation device 1 includes the electric circuit 102 is illustrated as an example of the ultraviolet LED irradiation device according to the present embodiment. In the embodiment of FIG. 3 and FIG. 10, the ultraviolet LED irradiation device 1 includes four ultraviolet LEDs, but is not limited to this, and may include any number of ultraviolet LEDs. The electric circuit 102 includes a series section 104, a first circuit 105, a second circuit 106, and a bypass circuit. The bypass circuit includes a first bypass circuit and a second bypass circuit. As shown in FIG. 10, the series section 104 includes a switch 140, a first limiting resistor 120, ultraviolet LEDs 114, 113, 112, and 111, in that order, with the one closer to the positive electrode on the electric circuit at the front. The number of ultraviolet LEDs is not limited, and they may be connected in series as shown in FIG. 10, with the one closer to the positive electrode on the electric circuit at the front.

[0042] Further, the series section 104 includes a third connection section 118 in front of the ultraviolet LED 114, a second connection section 115 between the ultraviolet LED 114 and the ultraviolet LED 113, a second connection section 116 between the ultraviolet LED 113 and the ultraviolet LED 112, and a second connection section 117 between the ultraviolet LED 112 and the ultraviolet LED 111. However, any number of ultraviolet LEDs can be provided, and when N ultraviolet LEDs are provided in the series section 104, N-1 second connection sections are provided, and second connection sections are provided between all adjacent ultraviolet LEDs connected in series. Furthermore, the series section 104 includes a third connection section 118 in front of the ultraviolet LED 114 when the one closer to the positive electrode on the electric circuit is the front. That is, in the electric circuit 102, when N ultraviolet LEDs are provided in the series section 104, the third connection section 118 is provided in front of the ultraviolet LED 114, which is the first ultraviolet LED of the ultraviolet LEDs connected in series, when the one closer to the positive electrode is the front. Only one third connection portion is provided in the electric circuit 102 as well.

[0043] Next, the first circuit 105 in the electric circuit 102 will be described as an example of the ultraviolet LED irradiation device according to the present embodiment. The first circuit 105 includes first connection parts 108, 109, 110, and 119. However, since any number of ultraviolet LEDs can be provided, when N ultraviolet LEDs are provided in the series section 4, the same number of N first connection parts are provided. In FIG. 10, the number of ultraviolet LEDs is four, and the number of first connection parts is four. When the side closer to the positive electrode on the electric circuit is the front, the series section 104 refers to the part from the switch 140 to the ultraviolet LED 111, which is the rearmost ultraviolet LED among the ultraviolet LEDs, and the first circuit 105 refers to the part connecting the power source 3 and the switch 140.

[0044] Next, the first bypass circuit of the electric circuit 102, which is an example of the ultraviolet LED irradiation device according to this embodiment, will be described in detail. When N ultraviolet LEDs are provided, the first bypass circuit of the electric circuit 102 is provided in the same number N, and is a circuit that connects any one of the first connection parts and any one of the second connection parts by a path other than the direct connection between the first circuit 105 and the series part 104. However, this number is not limited to the case where two or more ultraviolet LEDs are turned on. In the electric circuit 102, which is an embodiment shown in FIG. 10, the first bypass circuit includes a circuit that connects the first connection part 119 and the second connection part 117, a circuit that connects the first connection part 108 and the second connection part 116, and a circuit that connects the first connection part 110 and the third connection part 118. In other words, the first bypass circuit is a circuit that connects one first connection part and one second connection part or one third connection part. Each of the first bypass circuits includes a first switch and a second limiting resistor. Any known components may be appropriately used for the components constituting the electric circuit 2 in the present disclosure, such as the first switch.

[0045] Furthermore, the order of the first connection parts 119, 108, 109, and 110 in the first circuit 105 is not limited to that shown in the figure, and may be any order, such as 109, 108, 110, and 119.

[0046] Next, the second circuit 106 will be described in detail. The second circuit 106 refers to a portion that connects the ultraviolet LEDs 111 provided in the series unit 104 to the power source 3, with the side closer to the positive electrode being the front in the electric circuit. The second circuit 106 includes fourth connection portions 145, 146, and 147. When N ultraviolet LEDs are provided in the series unit 104, N-1 fourth connection portions are provided in the second circuit 6. The order of the fourth connections 145, 146, 147 is not limited to that shown in FIG. 3 and may be any order.

[0047] Next, the second bypass circuit will be described in detail. The second bypass circuit is a circuit that connects any one of the second connection parts 115, 116, 117 and any one of the fourth connection parts 145, 146, 147 via a path different from the circuit that directly connects the series part 104 to the second circuit 106. Each second bypass circuit includes second switches 141, 142, 143. As shown in FIG. 10, among the three second bypass circuits, the one that connects the second connection part 115 and the fourth connection part 145 includes the second switch 141. The second bypass circuits that connect the second connection parts 116, 117 and the fourth connection parts 146, 147 also include second switches 142, 143, respectively. When the ultraviolet LEDs are turned on one by one, the second bypass circuit is provided with N-1 ultraviolet LEDs when N ultraviolet LEDs are provided in the series section 104 in the electrical circuit 102, but is not limited to this when two or more ultraviolet LEDs are turned on one by one.

[0048] As in the embodiments of Figures 3 and 4, the second connection part may be configured in two ways: a path that directly connects the first bypass circuit between the ultraviolet LED 114 and the ultraviolet LED 113 in the series part 104, and a path that directly connects the second bypass circuit between the ultraviolet LED 114 and the ultraviolet LED 113. Alternatively, the first bypass circuit that connects the first connection part 109 and the second connection part 115 may be connected to the second bypass circuit at the fifth connection part 134, so that the section from the fifth connection part 134 to the second connection part 115 is configured as a shared section in which the first bypass circuit and the second bypass circuit are shared.

[0049] Next, the normal operation of the electric circuit 102 will be described in detail. During normal operation, only the switch 140 is in the on state, and all other switches are in the off state. In this case, the current preferentially passes through the path from the first circuit 105 through the series part 104 and the second circuit 106, and no current flows through the other paths. The first limiting resistor 120 is provided to prevent the ultraviolet LED elements from being damaged, and is configured to have a resistance value smaller than that of the second limiting resistors 121, 122, 123, and 124 so that the ultraviolet irradiation has sufficient strength.

[0050] Next, the LED check operation of the electric circuit 102, when checking the ultraviolet LED 111, will be described in detail. When checking the ultraviolet LED 111, only the first switch 137 is in an ON state, and the other switches shown in FIG. 10 are in an OFF state. Then, the current passes through the first bypass circuit, passes through the ultraviolet LED 111, and passes through the second circuit 106. By controlling the switches in this way, only the ultraviolet LED 111 can be turned on, and it is possible to check the lighting of the ultraviolet LED 111 and to confirm that there is no disconnection around the ultraviolet LED 111. In the first bypass circuit, the current passes through the second limiting resistor 124, which has a higher resistance value than the first limiting resistor 120 and is configured to have a value that weakens the ultraviolet intensity to a degree that the lighting of the LED can be visually confirmed. The same applies to the other second limiting resistors 121, 122, and 123. In addition, the resistance value of the second limiting resistor is preferably 10 to 1000 times the resistance value of the first limiting resistor. In this way, by configuring the resistance value of the second limiting resistor to be higher than the resistance value of the first limiting resistor, even if ultraviolet light enters the eyes of an operator during the LED check operation, the emission of the ultraviolet LED can be checked and is sufficiently weak, making it easier for the operator to check the LED and reducing the risk, which is advantageous.

[0051] Next, the LED check operation of the electric circuit 102, when checking the ultraviolet LED 112, will be described in detail. When checking the ultraviolet LED 112, the first switch 133 and the second switch 143 are in the ON state, and the other switches shown in FIG. 10 are in the OFF state. When checking the ultraviolet LED 112, the current flows from the first connection part 108 of the first circuit 105 through the first bypass circuit, enters the series part 104 from the second connection part 116, passes through the ultraviolet LED 112, enters the second bypass circuit from the second connection part 117, enters the second circuit 106 through the fourth connection part 147, and flows to the power source 3. No current flows through other paths. By controlling the switches in this way, only the ultraviolet LED 112 can be turned on, and it is possible to inspect the lighting of the ultraviolet LED 112 and to confirm that there is no disconnection around the ultraviolet LED 112.

[0052] In the case of the ultraviolet LEDs 113, 114, by controlling the switch in the same manner as already described, the ultraviolet LEDs 113, 114 can be turned on one by one, making it possible to check whether the ultraviolet LEDs 113, 114 are on and to confirm that there are no breaks in the wiring around the ultraviolet LEDs 113, 114.

[0053] In the cases of Figures 3, 4 and 10, a second connection section is provided between each ultraviolet LED in the series section, and by controlling the first switch and the second switch, it is possible to pass current to only one of the ultraviolet LEDs and not to pass current to the other ultraviolet LEDs.

[0054] Next, the control of the control unit (not shown) included in the ultraviolet LED irradiation device 1 of this embodiment will be described in detail. The control unit can be a known one, such as a configuration in which a computer (microcomputer, IC) controls control devices (relays and semiconductors (FET, transistor, photocoupler, etc.)). The control unit is configured to be able to control the electric circuits 2, 2' shown in Figs. 3 and 4 to turn on and off the switch 40, the first switches 31, 32, 33, and the second switches 41, 42, 43, 44 as shown in Figs. 5 to 9. That is, the control unit is configured to be able to control the state of Fig. 5 during normal operation so that only the switch 40 is turned on and the other switches shown are turned off. Then, during the LED check operation, the control unit is configured to be able to control the state of Fig. 6, for example, so that only the ultraviolet LED 11 is turned on, and then the state of Fig. 7 so that only the ultraviolet LED 12 is turned on. For example, the switch 40, the first switches 31, 32, 33 and the second switches 41, 42, 43, 44 can be controlled to be turned on and off so that the LED check operation is performed in the order of Figures 6, 7, 8, and 9, but the order of the LED check operation and the number of LEDs to be lit at one time are not limited to this.

[0055] The control of the switches of the control unit will be described in more detail, taking into consideration the way in which the current flows. During normal operation as shown in FIG. 5, the series unit 4, 104 is configured to allow current to flow, and in the cases shown in FIG. 6, FIG. 7, and FIG. 8, when the one closer to the positive electrode on the electric circuit 2 is considered to be the front, the switch 40, the first switches 31, 32, 33, and the second switches 41, 42, 43, 44 are controlled to be on and off so that the current flows through one ultraviolet LED that is the target of the LED operation check via one before and one after the second connection part or the third connection part adjacent to the second connection part on the electric circuit, and no current flows through the other ultraviolet LEDs of the series unit 4. This is also the case with the electric circuit 102.

[0056] 9, when the side closer to the positive electrode on the electric circuit is regarded as the front, the switch 40, the first switches 31, 32, 33, and the second switches 41, 42, 43, 44 are controlled to be on and off so that a current flows through one ultraviolet LED 14 that is the target of the LED operation check via the second connection part 15 on the rear side of the ultraviolet LED 14 adjacent to the ultraviolet LED 14 on the electric circuit 2, and no current flows through the other ultraviolet LEDs in the series section 4. This is also the case with the electric circuit 102.

[0057] In this way, by making the current flow through the serial section 4 during normal operation and passing through a resistor with a low resistance value by the first limiting resistor 20, strong and uniform ultraviolet irradiation can be ensured during normal operation as shown in FIG. 1, and during the LED check operation, when the lid is open as shown in FIG. 2, the control section detects that the lid is open and controls each switch to perform the LED check operation, so that the worker can check the health of the ultraviolet LEDs one by one for weak ultraviolet light irradiation. When there are N ultraviolet LEDs, the LED check operation is preferably performed for each ultraviolet LED, and as a result, N times are performed, but this is not limited to this because there are cases where two ultraviolet LEDs are turned on at a time. This explanation is also true for the electric circuit 102. [Industrial Applicability]

[0058] The ultraviolet LED irradiation device of the present disclosure is an irradiation device that can check the soundness of ultraviolet LEDs individually, and can be used as an ultraviolet irradiation device for fluorescent magnetic particle inspection and fluorescent penetrant inspection. Furthermore, it is a device with wide applications that can be used as an ultraviolet irradiation device for ultraviolet sterilization devices, ultraviolet curing devices, etc. Furthermore, it can be applied to irradiation devices of visible light and infrared rays. [Explanation of symbols]

[0059] 1 Ultraviolet LED irradiation device 2,2´,102 Electrical Circuit 3 Power supply 4,104 In-line section 5,105 First Circuit 6,106 Second Circuit 8,9,10,108,109,110,119 First connection 11,12,13,14,111,112,113,114 UV LED 15,16,17,115,116,117 Second connection 18,118 Third Connection 20,120 First limiting resistor 21,22,23,24,121,122,123,124 Second limiting resistor 31, 32, 33, 131, 132, 133, 137 First Switch 34, 35, 36, 134, 135, 136 Fifth connection 40,140 Switches 41, 42, 43, 44, 141, 142, 143 Second switch 45,46,47,48,145,146,147 Fourth connection 50,51 Fixtures 52 Lid 53 Irradiation unit 54 cases 55 Fluorescent Materials 56,57,58,59 UV LED housing

Claims

1. In an ultraviolet LED irradiation device for flaw detection having a plurality of ultraviolet LEDs, The ultraviolet LED irradiation device includes an electric circuit for turning on the ultraviolet LED, The ultraviolet LEDs are connected in series on the electric circuit, The plurality of ultraviolet LEDs are configured to be individually replaceable, The ultraviolet LED irradiation device, characterized in that the electrical circuit has one or more bypass circuits that can individually light up the multiple ultraviolet LEDs.

2. 2. The ultraviolet LED irradiation device according to claim 1, wherein the electrical circuit comprises a series section in which the ultraviolet LEDs are connected in series, the series section further comprising a first limiting resistor, the bypass circuit comprises a second limiting resistor, and the second limiting resistor has an electrical resistance greater than that of the first limiting resistor.

3. The electric circuit is composed of a power source, a series section in which a plurality of the ultraviolet LEDs are connected in series, a first circuit connecting the power source to the series section, a second circuit connecting the series section to the power source, and the bypass circuit; the bypass circuit comprises a first bypass circuit and a second bypass circuit, the first bypass circuit includes a first switch, the second bypass circuit includes a second switch, The series section includes a second connection section between the plurality of ultraviolet LEDs connected in series, the second connection is connected to the first bypass circuit and the second bypass circuit; the first bypass circuit is connected to the first circuit via a first connection part, and the second bypass circuit is connected to the second circuit via a fourth connection part; 3. The ultraviolet LED irradiation device according to claim 1, wherein the electrical circuit is configured to control the on / off of the first switch and the second switch, so that the ultraviolet LEDs can be turned on individually.

4. The ultraviolet LED irradiation device according to claim 3, further comprising a case and a lid, and configured to enable inspection of the ultraviolet LEDs by opening the lid, the ultraviolet LED irradiation device further comprising a sensor and a control unit that detects opening and closing of the lid, and the control unit is configured to be capable of controlling the on / off of a switch, the first switch, and the second switch so as to perform a normal operating operation when the lid is closed, and to perform an LED check operation when the lid is open.

5. The ultraviolet LED irradiation device according to claim 1 , further comprising a case and a lid, and a fluorescent member that emits light when irradiated with ultraviolet light is provided on an inner surface of the lid.

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