JP2023109964A - light irradiation system - Google Patents

Abstract

To provide a light irradiation system that can accurately detect a failure of an LED.SOLUTION: This light irradiation system comprises a plurality of LEDs 11, a sensor for detecting light from the LEDs 11, and control means for intermittently lighting the plurality of LEDs 11 to harden resin. The control means can light the plurality of LEDs 11 in an inspection mode. In the inspection mode, the control means lights the plurality of LEDs 11 for each group in a non-lighting period during intermittent lighting and detects an LED failure based on a comparison result between an output value of the sensor 90 and a reference value 120b.SELECTED DRAWING: Figure 1

Description

The present invention relates to light illumination systems.

As a lighting device having a plurality of LEDs arranged linearly in a predetermined direction, for example, the detection position of a sensor such as a line sensor camera in inspection of various manufacturing processes such as steel plate, plate glass, food, banknotes, etc. There is known a linear illumination device that illuminates in a line according to the angle of view (see, for example, Patent Document 1).

In addition, as a light irradiation device having a plurality of ultraviolet LEDs arranged on a plane, for example, in various manufacturing processes for manufacturing films made of ultraviolet-curable plastics, ultraviolet rays are used to harden plastics and form films. A planar light irradiation device for irradiation is known (see, for example, Patent Document 2).

JP 2007-225591 A JP 2011-079157 A

In order to ensure the quality of products such as films, this type of light irradiation device needs to uniformly irradiate strong light to the light irradiation position.
Hundreds or thousands of LEDs of the latter light irradiation device are often arranged at small pitches. Since the light from each LED cures the photocurable plastic, if some of the LEDs fail such as a short circuit or a decrease in brightness, the quality of the product is degraded.

In order to prevent deterioration in product quality, etc., it is conceivable to place an illuminometer in the light irradiation direction of the light irradiation device and inspect that each LED is normally lit before inspection or manufacturing. . However, the light irradiation device is often installed in an inspection line or a manufacturing line, and it is difficult to accurately inspect the illuminance with an illuminometer.

It is also conceivable to provide a sensor for each of the plurality of LEDs and monitor the presence or absence of failure of each LED based on the output of the sensor. However, it is not realistic to provide a sensor for each of all LEDs. Further, when the sensor and the LED are one-to-one, if the output value of the sensor decreases, it is possible that not only the LED is defective but also the detection accuracy of the sensor is degraded. In particular, when the LED emits ultraviolet light, there is concern about premature failure of the sensor when the LED is a high-brightness LED.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light irradiation system capable of accurately detecting a failure of an LED.

In order to solve the above problems, a light irradiation system according to an aspect of the present invention includes a light irradiation device main body, a plurality of LEDs provided in the light irradiation device main body, and a sensor that detects light from the LEDs. and a control means for intermittently lighting the plurality of LEDs for curing a resin, wherein the control means is capable of lighting the plurality of LEDs in an inspection mode, wherein the inspection mode is , the control means lights the plurality of LEDs in groups during the intermittent light-off period, and the control means detects an LED failure based on a comparison result between a detection value of the sensor and a reference value at that time. judge.

In this aspect, the control means lights up a plurality of LEDs for each group, the control means stores a reference value for each group, and the failure of each LED is determined using a smaller number of sensors than the group. . It is also possible to provide sensors for each group. However, if a sensor is provided for each group, the number of sensors increases, and checking the detection accuracy of the sensors is troublesome due to the large number of sensors. In particular, when the LED emits ultraviolet rays, there is concern about early failure of the sensor.

When the sensor and group are one-to-one, if the output value of the sensor drops, not only is there a possibility that some of the LEDs in the group are malfunctioning, but it is also possible that the detection accuracy of the sensor is declining. be. On the other hand, when the number of sensors is smaller than the number of groups, one sensor is in charge of two or more groups. Simultaneous LED failures in each of two or more groups are unlikely. Therefore, when the output value of the sensor for any one of two or more groups decreases, the detection accuracy of the sensor does not decrease, but it means that the LED in that group is malfunctioning. Thus, the light irradiation system of each of the above embodiments can accurately detect failure of the LED.

According to the present invention, LED failures can be accurately detected.

It is a top view of the light irradiation device of the LED light irradiation system according to the first embodiment of the present invention. FIG. 2 is a circuit configuration diagram for lighting the LEDs of the LED light irradiation system of the first embodiment; It is a cross-sectional view of a light irradiation device of the LED light irradiation system of the first embodiment. FIG. 2 is a cross-sectional view of a main part of the light irradiation device of the LED light irradiation system of the first embodiment; FIG. 2 is a cross-sectional view of a main part of the light irradiation device of the LED light irradiation system of the first embodiment; It is an example of a time chart of lighting control by the control device of the first embodiment. 8 is another example of a time chart of lighting control by the control device of the first embodiment; FIG. 4 is a cross-sectional view of a main part of a modification of the light irradiation device of the LED light irradiation system of the first embodiment; FIG. 6 is a longitudinal cross-sectional view of a light irradiation device of an LED light irradiation system according to a second embodiment of the present invention; FIG. 10 is a lateral cross-sectional view of a light irradiation device of an LED light irradiation system according to a second embodiment; FIG. 3 is a plan view of a substrate 10 showing a modification of the light irradiation device of the LED light irradiation system according to the first embodiment; FIG. 10 is a cross-sectional view of a main part of another modification of the light irradiation device of the LED lighting system of the first embodiment; FIG. 10 is a cross-sectional view of a main part of another modification of the light irradiation device of the LED lighting system of the first embodiment;

An LED light irradiation system according to a first embodiment of the present invention will be described below with reference to the drawings.
This LED light irradiation system, for example, irradiates a predetermined area with light in order to cure a photocurable resin. As shown in FIG. 2, this LED light irradiation system connects a light irradiation device 1, a power supply unit 2, and the light irradiation device 1 and the power supply unit 2 to connect the power supply unit 2 to the light irradiation device 1. and a connection cord 3 for supplying power. The connection cord 3 supplies driving power to the light irradiation device 1 .

The light irradiation device 1 has a plurality of substrates 10, as shown in FIGS. 1 and 2, and each substrate 10 has a plurality of LEDs 11 connected in series. An FET (field effect transistor) 12 as a transistor and a current detection resistor 13 are connected to each LED substrate 10 via a connection cord 3 . The drain terminal of FET 12 is connected to the low potential end of a plurality of LEDs 11 (LED series circuit) connected in series, and the source terminal of FET 12 is connected in series with current detection resistor 13 .

In this embodiment, the FET 12 is connected to the low potential end of the LED series circuit, but it is also possible to connect the FET 12 to the high potential end of the LED series circuit. In this case, the source terminal of FET 12 is connected to the high potential end of the LED series circuit.

Each LED board 10 has a high potential side power supply section 14a connected to the high potential end of the DC power supply D of the power supply unit 2 via the connection cord 3, and a low potential side power supply section 14b connected to the FET 12. and

As shown in FIGS. 1 and 2, the power supply unit 2 has one or a plurality of light control boards 20, and each light control board 20 controls the light of the plurality of LED boards 10 one by one. It is configured. Although the light control board 20 is provided in the power supply unit 2 in this embodiment, the light control board 20 may be provided in the light irradiation device 1 . A dimming signal supply unit 30 that supplies a dimming signal to each dimming substrate 20 is provided in the power supply unit 2, and the dimming signal supply unit 30 sets the amount of current to be supplied to each of the plurality of LED substrates 10. can do. For example, the dimming signal supply unit 30 transmits to each dimming substrate 20 a dimming signal for each LED substrate 10 according to information input by the operator to the input unit 40 of the power supply unit 2 .

Each dimming board 20 supplies the received dimming signal to the reference potential input section 21b of each operational amplifier 21 via a D/A converter (not shown). That is, each dimming board 20 supplies the reference potential based on the dimming signal from the dimming signal supply part 30 to the reference potential input part 21 b of the operational amplifier 21 corresponding to each LED board 10 .
Since it is configured in this way, the light irradiation position just below the end of the plurality of LEDs 11 arranged in parallel and the light irradiation position just below the center of the plurality of LEDs 11 arranged in parallel have the same amount of light. adjustment is possible. In addition, even if there is variation in the light intensity of each LED 11 due to manufacturing factors or the like, it is possible to make adjustments to reduce the variation in the light intensity at the light irradiation position.

The output terminal 21 c of the operational amplifier 21 is connected to the gate terminal of the FET 12 , and the comparison potential input section 21 a of the operational amplifier is connected between the source terminal of the FET 12 and the current detection resistor 13 on the LED substrate 10 .

As shown in FIG. 2, a well-known constant current circuit having an FET 12, a current detection resistor 13, and an operational amplifier 21 is constructed. In this constant current circuit, the FET 12 supplies a drive current from the DC current device D to the connected LED series circuit. In addition, by this constant current circuit, the potential of the high potential side of the current detection resistor 13 changes according to the potential of the reference potential input section 21b of the operational amplifier. It is possible to control the flowing current (adjust the light amount of each LED 11). A constant voltage circuit may be used instead of the constant current circuit.

Since it is comprised as mentioned above, the power supply unit 2 of this embodiment can make several LED11 light for every group. Specifically, in this embodiment, the power supply unit 2 can turn on the LED 11 for each board 10 .

Each LED substrate 10 is made of, for example, an aluminum plate, and is fixed in surface contact with a heat sink 72a provided in the light irradiation device main body 71 and extending along the substrate 10 . In this embodiment, as shown in FIG. 3, the lower heat sink 72b to which the heat sink 72a is fixed is fixed to the light irradiation device main body 71. As shown in FIG. The light irradiation device main body 71 includes a lower body 71a to which the lower heat sink 2b is fixed, a plurality of side plates 71b whose lower ends are fixed to the ends of the lower body 71a, the lower body 71a and the side plates 71b. and a cover (transparent plate or transparent member) 80 that covers the upper end side of the space formed by The cover 80 is made of translucent material such as acrylic plastic or glass. The heat sink 72a and the lower heat sink 72b may be of an air-cooling type, but a water-cooling type can perform cooling without being influenced by the surrounding environment.

This light irradiation device 1 is provided with a sensor 90 capable of detecting the amount of light at the end of the cover 80 . As the sensor 90, a photodiode, a photometer, or the like that can detect the amount of light can be used. The detection result of the sensor 90 is transmitted to the control device (control means) 100 of the power supply unit 2 .

A plurality of substrates 10 are provided with fewer sensors 90 than the number of substrates 10 concerned. In this embodiment, two sensors 90 are provided for twelve substrates 10 . One of the two sensors 90 is arranged on one end side of the cover 80 and detects light emitted from the one end of the cover 80 . The other of the two sensors 90 is arranged on the other end side of the cover 80 and detects light emitted from the other end of the cover 80 .
In this embodiment, as shown in FIG. 1, the direction in which the LEDs 11 are arranged side by side between one end and the other end of the cover 80 may be referred to as the X direction. The direction is sometimes referred to as the Y direction.

In this embodiment, one surface in the thickness direction of the cover 80 is an incident surface 80a on which light from the LED 11 is incident, and the other surface in the thickness direction is an output surface 80b from which light is emitted. A plurality of reflecting portions 81 are provided on the cover 80 . Each reflecting portion 81 is, for example, a concave portion provided in the exit surface 80b. In this embodiment, the recess has four inclined surfaces. As shown in FIG. 5, two of the four inclined surfaces 81a and 81b are arranged in the X direction, and the other two inclined surfaces are arranged in the Y direction. In one example, the recess has a pyramidal shape.

The two inclined surfaces 81a and 81b aligned in the X direction are approximately triangular or triangular, respectively, and the two inclined surfaces aligned in the Y direction are also approximately triangular or triangular. Each of the two inclined surfaces 81a and 81b aligned in the X direction may be substantially trapezoidal or trapezoidal, and each of the two inclined surfaces aligned in the Y direction may be substantially trapezoidal or trapezoidal. In this embodiment, as shown in FIG. 5, the angle β formed between the inclined surfaces 81a and 81b and the output surface 80b is 30°. The angle β may be another angle as long as the functions described later are satisfied.

As shown in FIG. 4 , each reflector 81 corresponds to a plurality of LEDs 11 . As shown in FIG. 1 , in this embodiment, each reflecting portion 81 is arranged at the center position of the four LEDs 11 when viewed from the optical axis LA direction of the LEDs 11 . In addition, in this embodiment, three reflecting portions 81 are arranged for the twelve LEDs 11 on one substrate 10 in plan view. In addition, the reflection part 81 may be arrange|positioned in the central position of three LED11, the central position of two LED11, the central position of five LED11, or the central position of six LED11.

As shown in FIGS. 4 and 5, the surfaces 81a and 81b reflect light from the corresponding LEDs 11 in the X direction. That is, the surfaces 81 a and 81 b reflect the light from the corresponding LEDs 11 toward the sensor 90 .

As shown in FIG. 5, light that forms an angle α with the optical axis LA of the LED 11 enters the surfaces 81a and 81b. It is preferable that the angle obtained by adding the angle β to the angle α is equal to or greater than the critical angle of the material of the cover 80 . If the refractive index of the material forming the cover 80 is approximately 1.5, the critical angle is approximately 42°. Since the angle β is 30° in this embodiment, the light from the LED 11 forming an angle of 12° or more with the optical axis LA is totally reflected by the surfaces 81a and 81b.
It should be noted that the total reflection is not necessarily required. Even if the angle obtained by adding the angle β to the angle α is less than the critical angle of the material of the cover 80 , part of the light incident on the inclined surfaces 81 a and 81 b is reflected toward the sensor 90 .

The control device 100 is, as shown in FIG. 2, a computer having a processor 110, a storage unit 120, a RAM, etc., an integrated circuit having the same functions as the computer, or the like.

The storage unit 120 stores a lighting program 120a and a set of reference values 120b. The lighting program 120 a is for causing a set current to flow through each substrate 10 . The lighting program 120a causes a set current to flow through each substrate 10, as shown in the time chart shown in FIG. 6, for example.

The storage unit 120 stores a reference value 120b for each of the plurality of substrates 10. FIG. The reference value 120b may be created based on a reference creation program 120c stored in the storage unit 120. FIG. For example, the processor 110 illuminates the LED 11 for each substrate 10 based on the reference creation program 120c, and detects the detection values of the two sensors 90 provided corresponding to the substrate 10 that has been illuminated. 10, and stored in the storage unit 120 as a reference value 120b. The detection values of the two sensors 90 may be stored separately in the storage unit 120 , or the average value, added value, or the like of the detection values of the two sensors 90 may be stored in the storage unit 120 . The identification information of the substrate 10 may be the number of the substrate 10, positional information, and the like.

The light irradiation device 1 or the power supply unit 2 may be provided with an operation section such as a button 41 for starting reference setting. In this case, the processor 110 may measure the reference value 120b described above and store it in the storage unit 120 according to the operation of the operation unit. Alternatively, the processor 110 may measure the reference value 120b and store it in the storage unit 120 according to a predetermined signal from an external computer such as a tablet computer. Since the reference value 120b may change depending on the environment in which the light irradiation device 1 is arranged, the setting of the reference value 120b according to the operation of the operation unit or the signal from the computer is necessary for accurate failure detection of the LED 11. It is advantageous to

Based on the lighting program 120a, the processor 110 lights the LEDs 11 in the inspection mode while the plurality of substrates 10 are emitting light, as shown in FIG. As shown in FIG. 6, the processor 110 turns on the LEDs 11 of the plurality of substrates 10 for a predetermined lighting period L1, and then turns off the LEDs 11 for a predetermined lighting period L2. The processor 110 simultaneously turns on and off the multiple substrates 10 .

The processor 110 performs lighting in the inspection mode based on the lighting program 120a while performing the lighting and extinguishing described above. Lighting in the inspection mode is performed during the light-out period L2. Also, the lighting in the inspection mode is performed by lighting the plurality of substrates 10 one by one as shown in FIG. 6, for example. In FIG. 6, the processor 110 selects No. during the first turn-off period L2. Only the substrate 10 numbered 1 is turned on, and the numbered substrate 10 is turned on during the second turn-off period L2. Only the substrate 10 numbered 2 is turned on, and the number No. 2 is turned on during the third turn-off period L3. Only the substrates 10 numbered 3 are lit, and then the substrates 10 are similarly lit one by one.

That is, the processor 110 lights the plurality of LEDs 11 in the inspection mode for each group. In addition, in the inspection mode, the processor 110 may light up a plurality of substrates 10, such as two or three. Even in this case, it can be said that the processor 110 lights the plurality of LEDs 11 for each group.

When the inspection mode is turned on, the processor 110 compares the detection values of the two sensors 90 corresponding to the board 10 that has been turned on with the reference value 120b of the board 10, and based on the comparison result, turns on the board 10. Failure determination of the LED 11 is performed. In the present embodiment, each board 10 has 12 LEDs 11, so if one of the 12 LEDs 11 fails to light due to a failure, the detected values of the two sensors 90 are 5% or more of the reference value 120b, for example. become smaller. Therefore, the comparison enables the processor 110 to determine the failure of each board 10 .

Note that in the present embodiment, the reference value 120b for each substrate 10 is stored in the storage unit 120 in advance. On the other hand, the detection value of the corresponding sensor 20 when each board 10 is lit in the inspection mode may be stored in the storage unit 120 as the reference value 120b of each board 10 . In this case, when the reference value 120b is created, the light irradiation device 1 is placed in an environment in which it is actually used, and an object to which the light irradiation device 1 irradiates light also exists. Therefore, the reference value 120b becomes more accurate.

Alternatively, as shown in FIG. 7, the inspection mode lighting may be performed by keeping the target substrate 10 lit during the light-off period L2. Even in this case, it is possible to create the reference value 120b. Also, in this case, even if the light-out period L2 is short, the amount of light emitted from the LED 11 in the inspection mode is stable. If the amount of light irradiation is important, the shorter the light-off period L2, the better. For example, the light-out period L2 may be several microseconds. In order to efficiently cure the resin, it is preferable that the light-out period L2 is 1 ms or less. It may be difficult to turn on the LED 11 in the inspection mode and then turn off the LED 11 in such a short time. In such a case, lighting in the inspection mode as shown in FIG. 7 is advantageous for stabilizing the light irradiation amount of each LED 11 in the inspection mode.

Also, as shown in FIG. 8, a shutter 91 may be provided to block the exposed portion of the sensor 90 . As the shutter 91, for example, an electronic shutter such as a well-known focal plane shutter, lens shutter, electronic front curtain shutter, rolling shutter, or the like can be used. Based on the lighting program 120a, the processor 110 controls the shutter 91 so that the shutter 91 is closed during the lighting period L1 and opened during the lighting period L2. The processor 110 may open only the shutter 91 of the sensor 90 corresponding to the substrate 10 to be lit in the inspection mode during the extinguishing period L2.

This configuration prevents the sensor 90 from deteriorating due to the sensor 90 being irradiated with a large amount of light from all the LEDs 11 during the lighting period L1. In particular, when each LED 11 emits ultraviolet light, or when each LED 11 is a high-brightness LED, deterioration of the sensor 90 is effectively prevented by the shutter 90 .
Sensor 90 may be housed in case 92 and sensor 90 may be covered by case 92 and shutter 91 . In this case, deterioration of the sensor 90 is more effectively prevented.

An LED light irradiation system according to a second embodiment of the present invention will be described below with reference to the drawings.
As shown in FIGS. 9 and 10, this LED light irradiation system uses a light irradiation device 4 for linear light irradiation instead of the light irradiation device 1 for planar light irradiation in the first embodiment. is. This LED light irradiation system has the same power supply unit 2 and connection cord 3 as in the first embodiment. The same reference numerals are given to the same configurations as in the first embodiment, and the description thereof will be omitted.

The light irradiation device 4 has a plurality of substrates 10, and each substrate 10 has a plurality of LEDs 11 connected in series. The connection between the power supply unit 2 and each board 10 is the same as in the first embodiment. Therefore, even in the second embodiment, the power supply unit 2 can turn on the plurality of LEDs 11 for each group, for example, for each board 10 .
The light irradiation device 4 is provided with a sensor 90 capable of detecting the amount of light at the end of the cover 80 , and the detection result of the sensor 90 is transmitted to the control device 100 of the power supply unit 2 .

Also in the second embodiment, the number of sensors 90 smaller than the number of substrates 10 is provided for a plurality of substrates 10 . Specifically, the light irradiation device 4 is provided with one sensor 90 at each end in the direction in which the LEDs 11 are arranged side by side, and the light irradiation device 4 has three or more substrates 10 . Each sensor 90 detects light emitted from the edge of the cover 80 . In the second embodiment, as shown in FIG. 10, the direction in which the LEDs are arranged may be referred to as the X direction, and the direction in which the cover 80 extends perpendicular to the X direction may be referred to as the Y direction. be.

As shown in FIGS. 9 and 10, the light irradiation device 4 is provided with a condensing lens 4a for condensing the light from the plurality of LEDs 11 in the Y direction. Further, as shown in FIGS. 9 and 10, a diffusion plate 4b for diffusing the light from the plurality of LEDs 11 may be provided. The light passes through the cover 80 after passing through the condenser lens 4a. The diffusion plate is made of transparent plastic, glass, or the like. Note that the condensing lens 4a and the diffusion plate 4b may be omitted.

A plurality of reflecting portions 81 similar to those in the first embodiment are provided on an emission surface 80b from which light from the LED 11 that has passed through the condensing lens 4a, the diffuser plate 4b, etc. is emitted, and the plurality of reflecting portions 81 are arranged in the X direction. I'm in.
As shown in FIG. 10, each reflecting portion 81 reflects light from the plurality of LEDs 11 in one or the other direction in the X direction within the cover 80, as in the first embodiment.

In the second embodiment as well, the storage unit 120 stores the reference value 120b for each of the plurality of substrates 10, similarly to the first embodiment or its modification.
Also in the second embodiment, the processor 110 turns on the LED 11 of each board 10 during the lighting period L1 and turns off the LED 11 during the lighting period L2 as shown in FIGS. Further, as in the first embodiment, the processor 110 turns on the plurality of substrates 10 one by one in the inspection mode during the extinguishing period L2, and the detection values of the two sensors 90 at that time are the reference values of the substrate 10. Compare with 120b. Further, the processor 110 performs failure determination of each board 10 based on the comparison result.
Thus, in the second embodiment, as in the first embodiment, it is possible to accurately determine failure of each substrate 10 while the light irradiation device 4 is in use.

In addition, in 1st Embodiment and 2nd Embodiment, the reflection part 81 may be abbreviate|omitted. Even in this case, for example, if the cover 80 is a diffusion plate and the incident surface 80a of the cover 80 is provided with irregularities for diffusion, part of the light from each LED is reflected by the output surface 80b. , some of the reflected light reaches the sensor 90 . When adopting such a cover 80 in the second embodiment, the diffusion plate 4b can be omitted. Also, the light from the LED 10 may reach the sensor 90 at the edge of the cover 80 by other methods.
Alternatively, a sensor 90 may be provided at the end of the condensing lens (transparent member) 4a, and the sensor 90 may detect light from the end of the condensing lens 4a.

Further, in the first embodiment and the second embodiment, the reflecting section 81 may be omitted and each sensor 90 may be provided on the substrate 10 . For example, as shown in FIG. 11, a sensor 90 may be arranged at the central position of the four LEDs 11. FIG. Even in this case, fewer sensors 90 than the number of substrates 10 are provided for the plurality of substrates 10 . In addition, the sensor 90 may be arranged at the central position of the three LEDs 11 , the central position of the two LEDs 11 , the central position of the five LEDs 11 , or the central position of the six LEDs 11 .
Also in this case, the storage unit 120 stores the reference value 120b for each of the plurality of substrates 10, as in the first embodiment or its modification.

Then, the processor 110 turns on the LED 11 of each substrate 10 during the lighting period L1 and turns off the LED 11 during the lighting period L2 as shown in FIGS. Further, as in the first embodiment, the processor 110 turns on the plurality of substrates 10 one by one in the inspection mode in the extinguishing period L2, and detects the detection values of the corresponding three sensors 90 at that time. Compare with reference value 120b. Therefore, as in the first and second embodiments, it is possible to accurately determine the failure of the LED 11 of each board 10 during use of the light irradiation device 1 .

In each of the embodiments described above, each reflecting portion 81 has a pyramid shape, but each reflecting portion 81 may have a dome shape. Each reflecting portion 81 may have another shape as long as it reflects part of the light from the corresponding LED 11 toward the sensor 90 .

In addition, in each of the above-described embodiments, it is also possible to provide the sensor 90 at other locations within the light irradiation devices 1 and 4 . Alternatively, it is also possible to provide the sensor 90 outside the light irradiation devices 1 and 4 . Even in these cases, if the reference value 120b of each substrate 10 is stored in the storage unit 120, each substrate can be detected by comparing the detection value of the sensor 90 with the reference value 120b when each substrate 10 is lit in the inspection mode. It is possible to accurately determine the failure of the 10 LEDs 11 .

Note that in each of the above-described embodiments, the reference value 120b is stored in the storage unit 120 of the control device 100, and the detection value of the sensor 90 is transmitted to the control device 100. FIG. On the other hand, the reference value 120b is stored in the storage unit of another control device which is a computer, the detection value of the sensor 90 is transmitted to the other control device, and the other control device controls each substrate 10 based on the reference value 120b. A failure of the LED 11 may be determined. In this case, control device 100 and other control devices function as control means.

In each of the above embodiments, the control device 100 intermittently lights the plurality of LEDs 11 so that the light irradiation devices 1 and 4 cure the resin. lights up for each group. Then, the control device 100 determines an LED failure based on the result of comparison between the detection value of the sensor 90 and the reference value 120b. In many cases, the light irradiation devices 1 and 4 for curing the resin are arranged deep in the process of curing the resin and manufacturing the product. In addition, since this step is for efficiently and accurately curing the resin, each LED 11 is not turned off while the resin to be cured is placed at the light irradiation position.

In this embodiment, it is possible to accurately determine whether or not there is a failure in the plurality of LEDs 11 during the extinguished period L2. That is, it is possible to constantly monitor whether or not the plurality of LEDs 11 are faulty while curing the resin. This configuration is extremely advantageous in ensuring or ensuring the quality of the manufactured product.

In each of the above embodiments, the control device 100 turns on the plurality of LEDs 11 for each group, the control device 100 stores the reference value 120b for each group, and each LED 11 failure is determined. It is also possible to provide sensors 90 for each group. However, if the sensors 90 are provided for each group, the number of sensors 90 increases, and checking the detection accuracy of the sensors 90 is time-consuming because of the large number of sensors 90 . In particular, when the LED 11 emits ultraviolet rays, the sensor 90 may fail at an early stage.

When the sensor 90 and the group are one-to-one, if the output value of the sensor 90 decreases, not only is there a possibility that some of the LEDs 11 in the group are defective, but also the detection accuracy of the sensor 90 is decreased. It is possible. On the other hand, when the number of sensors 90 is smaller than the number of groups, one sensor 90 is in charge of two or more groups. It is unlikely that failures of the LEDs 11 will occur simultaneously in each of two or more groups. Therefore, when the output value of the sensor 90 for any one of two or more groups decreases, the detection accuracy of the sensor 90 is not degraded, but the LED 11 of that group is faulty. . Thus, the light irradiation system of each said embodiment can detect the failure of LED11 correctly.

Also, in each of the above embodiments, the sensor 90 is arranged to detect light from the edge of the transparent plate or transparent member. Therefore, the sensor 90 will not reduce the amount of light for the light irradiation of the light irradiation devices 1 and 4 in the future. In addition, when the light irradiation devices 1 and 4 emit ultraviolet light, the sensor 90 is not directly irradiated with strong light in the irradiation range, so early failure of the sensor 90 can be prevented.

Further, in each of the above-described embodiments, since the light exit surface 80 b of the cover 80 is provided with the reflecting portion 81 , part of the light from the LED 11 can be efficiently directed to the end portion of the cover 80 . This is advantageous in accurately determining failure of the LED 11 based on the detected value of the sensor 90 .

In each of the above embodiments, the reflecting portion 81 is arranged at the center position of the plurality of LEDs 11 when viewed from the direction of the optical axis LA of the LEDs 11, and the influence of the light amount of each LED 11 on the detection value of the sensor 90 is approximately be equivalent. This is advantageous for accurately detecting whether or not each LED 11 is faulty.
As shown in FIG. 11 , the sensor 90 may be attached to the substrate 10 so as to be arranged at the central position of the plurality of LEDs 11 when viewed from the direction of the optical axis LA of the LEDs 11 . Even in this case, the influence of the light amount of each LED 11 on the detection value of the sensor 90 is substantially the same.

In each of the above-described embodiments, a single sensor 90 may be provided instead of the plurality of sensors 90 at the end of the cover (transparent plate) 90 or the condenser lens (transparent member) 4a. Even in this case, the same effect as described above can be achieved.

Also, as shown in FIG. 12, a light diffusion section 82 may be provided instead of the reflection section 81 . For example, the light diffusing portion 82 is provided by forming unevenness of several tens to several hundred μm on a part of the exit surface 80b. The unevenness may be uniform or random. For example, the light diffusing portion 82 is provided by physically or chemically roughening the exit surface 80b.

When the light diffusing portion 82 is provided instead of the reflecting portion 81 , the light from the LED 11 is diffused in various directions by the light diffusing portion 82 , and part of the light is directed toward the sensor 90 . It can also be said that the light diffusing portion 82 is also a reflecting portion that reflects light toward the sensor 90 .

In addition, as shown in FIG. 13, a light diffusion section 83 may be provided instead of the reflection section 81 . For example, the light diffusing portion 83 is provided by attaching a light diffusing sheet to a portion of the incident surface 80a. The light diffusing portion 83 may be provided by forming unevenness of several tens to several hundred μm on a part of the incident surface 80a. The unevenness may be uniform or random. For example, the light diffusing portion 82 is provided by physically or chemically roughening the exit surface 80b.
When the light diffusion portion 82 is provided instead of the reflection portion 81 , the light from the LED 11 is diffused in various directions by the light diffusion portion 83 and part of the light is directed toward the sensor 90 .

The light diffusing portion 82 or the light diffusing portion 83 accounts for 3% or less of the entire area of the cover 80 in a plan view of the cover 80 . Even if the area of the light diffusing part 82 or the light diffusing part 83 is 5% or less of the total area of the cover 80, it can be established as long as the amount of light to irradiate the object is ensured.

DESCRIPTION OF SYMBOLS 1, 4... Light irradiation apparatus 2... Power supply unit 3... Connection cord 10... LED board 11... LED 12... FET 13... Current detection resistor 20... Dimming board 21... Operational amplifier 30... Light control signal supply unit 40 Input unit 71 Light irradiation device body 80 Cover 80a Incident surface 80b Output surface 81 Reflector 90 Sensor 91 Shutter 100 Control device 120...storage unit, 120b...reference value, 120c...reference creation program.

In order to solve the above problems, a light irradiation system according to an aspect of the present invention includes a light irradiation device main body, a plurality of LEDs provided in the light irradiation device main body, and a resin cured by the plurality of LEDs. a control means capable of intermittently lighting the plurality of LEDs for each group during an extinguishing period of the intermittent lighting; and a sensor, wherein the control means lights the plurality of LEDs for each group during the light-off period of the intermittent lighting, and the detection value and the reference value of the sensor at that time and the control means determines at least one of a decrease in luminance and a short circuit of the LED.

In this aspect, the control means lights up the plurality of LEDs for each group, the control means stores the reference value for each group, and the reduction in brightness and short circuit of each LED are detected using a number of sensors smaller than that of the group. At least one is determined. It is also possible to provide sensors for each group. However, if a sensor is provided for each group, the number of sensors increases, and checking the detection accuracy of the sensors is troublesome due to the large number of sensors. In particular, when the LED emits ultraviolet rays, there is concern about early failure of the sensor.

When the sensor and the group are one-to-one, if the output value of the sensor decreases, not only is there a possibility that at least one of the LEDs in the group has a decrease in brightness and a short circuit , but also the detection accuracy of the sensor decreases. It is possible that they are. On the other hand, when the number of sensors is smaller than the number of groups, one sensor is in charge of two or more groups. It is unlikely that the brightness reduction of the LEDs in each of two or more groups will occur at the same time. Therefore, when the output value of the sensor for any one of two or more groups is reduced, the detection accuracy of the sensor is not reduced, but at least one of luminance reduction and short circuit occurs in the LEDs of the group. There will be Thus, the light irradiation system of each of the embodiments described above can accurately detect a decrease in the brightness of the LED.

Claims (7)

a light irradiation device main body;
a plurality of LEDs provided on the main body of the light irradiation device;
a sensor that detects light from the LED;
A light irradiation system comprising control means for intermittently lighting the plurality of LEDs to cure the resin,
The control means can light the plurality of LEDs in an inspection mode,
As the inspection mode, the control means lights the plurality of LEDs for each group during the intermittent light-off period, and based on the result of comparison between the detection value of the sensor and the reference value at that time, the control means determines LED failure, light illumination system. further comprising a transparent member provided in the light irradiation device main body and through which the light from the plurality of LEDs is transmitted;
2. The light illumination system of claim 1, wherein the sensor detects light from the edge of the transparent member. further comprising a transparent plate attached to the light irradiation device body and through which the light from the plurality of LEDs is transmitted;
One surface in the thickness direction of the transparent plate is an incident surface on which light from the plurality of LEDs is incident, and the other surface in the thickness direction is an output surface from which light is emitted,
The exit surface or the incident surface is provided with a plurality of reflecting portions or light diffusing portions for directing part of the light from the plurality of LEDs toward the edge of the transparent plate,
2. The light illumination system of claim 1, wherein the sensor is arranged to detect light from the edge of the transparent plate. 4. The light irradiation system according to claim 3, wherein said reflector is arranged at a center position of said plurality of LEDs when viewed from the optical axis direction of said plurality of LEDs. comprising a plurality of substrates on which the plurality of LEDs are mounted;
4. The light irradiation system according to any one of claims 1 to 3, wherein said sensor is attached to said substrate and arranged at a central position of said plurality of LEDs when viewed from the optical axis direction of said plurality of LEDs. 6. The light irradiation system according to any one of claims 1 to 5, wherein said plurality of LEDs are arranged side by side in a row in the X direction orthogonal to the optical axis of said LEDs. 6. The plurality of LEDs are arranged side by side in an X direction perpendicular to the optical axis of the LEDs and arranged side by side in a Y direction perpendicular to the optical axis and the X direction. The light irradiation system according to .

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