JP7008916B2 - Lighting equipment - Google Patents

Description

The present invention relates to a lighting device.

Conventionally, as a lighting device for irradiating a work with light, a lighting device for a line sensor camera that inspects the surface of the work (see, for example, Patent Document 1) and ultraviolet curing applied to the work by irradiating ultraviolet rays. Lighting devices for curing the resin (see, for example, Patent Document 2) and the like are widely used. Further, a technique has been proposed in which a part of the light from the lighting device is blocked by a shielding means to irradiate only the work so that the light is not irradiated to a part other than the work (see, for example, Patent Document 3).

Japanese Unexamined Patent Publication No. 2016-14669 Japanese Unexamined Patent Publication No. 8-255565 Japanese Unexamined Patent Publication No. 2010-89341

Here, as shown in FIG. 6A, the in-plane distribution of the intensity (illuminance) of the light emitted from the conventional lighting device 100 is not uniform, and the illuminance gradually decreases as it approaches the end of the irradiation area Ra. However, so-called sagging has occurred in the illuminance distribution. Therefore, in order to uniformly irradiate the entire work W with light, it is necessary to make the irradiation area Ra larger than the width of the work W as shown in FIG. 6 (b). However, when the irradiation area Ra is increased in this way, light is irradiated over a relatively wide range even outside the work W. The above-mentioned technique of Patent Document 3 blocks the irradiation of light to the outside of the work by reducing the irradiation area by the light-shielding means, but a driving means for operating the light-shielding means is required, and the lighting device becomes large. , The price will increase. Further, if the irradiation area Ra is made small as shown in FIG. 6A to suppress the irradiation of light to the outside of the work W, it becomes impossible to uniformly irradiate the work W with light, and FIG. 6B shows. As described above, when the irradiation area Ra is relatively large, the work W can be uniformly irradiated with light, but there is a problem that the irradiation of light other than the work W also increases.

Therefore, an object of the present invention is to provide a lighting device capable of irradiating a predetermined irradiation region with uniform light and reducing the amount of light emitted outside the irradiation region.

The lighting device of the present invention is a lighting device for irradiating a predetermined irradiation region with light, and is mounted on a substrate and a plurality of light sources mounted at a distance from each other in a first direction on the surface of the substrate. A light source row consisting of a light source column and a plurality of light shielding plates provided at intervals between the light sources of the light source array are provided, and the respective light shielding plates are formed from the surface of the substrate or its vicinity to the surface of the substrate. Of the light emitted from each light source and directed outward in the first direction, the light having an irradiation angle deeper than a predetermined angle is shielded from the light extending in the intersecting second direction, and further, the above-mentioned light-shielding plate of each light-shielding plate. By configuring the predetermined irradiation angle to gradually increase inward in the first direction, at least a part of the light emitted from each light source beyond the predetermined irradiation region is shielded from the light. In the direction, the first light-shielding plate provided outside the second light source from the outside blocks the light emitted from the second light source whose irradiation angle is deeper than the first predetermined angle. However, in the first direction, the second light-shielding plate provided outside the third light source from the outside has an irradiation angle deeper than the second predetermined angle of the light emitted from the third light source. The light of the angle is blocked, and the first predetermined angle is applied to the boundary between the predetermined irradiation region and the outer region of the light emitted from the second light source and directed outward in the first direction. The second predetermined angle is the irradiation angle of the light emitted from the third light source and directed outward in the first direction to the boundary. It is characterized by.

Further, the lighting device of the present invention is characterized in that the light-shielding plate is provided between a pair of adjacent light sources and inward in the first direction from the intermediate point of the pair of light sources. ..

Further, in the lighting device of the present invention, in the first direction, a reflector is provided on the outside of the light source row, and the light-shielding plate is provided on the outside of the i-th light source excluding the first light source from the outside. It is characterized by being.

Further, in the lighting device of the present invention, the light sources are arranged in a two-dimensional matrix, and the light-shielding plate corresponds to the i-th light source row from the outside in the first direction and is orthogonal to the first direction. It is characterized in that it extends in parallel with the light source line in the third direction.

According to the illuminating device according to the present invention, by blocking light having an irradiation angle deeper than a predetermined angle, at least a part of the light irradiated beyond the predetermined irradiation region is blocked, so that the illuminance distribution. It is possible to reduce sagging, which makes it possible to reduce the irradiation of light outside the irradiation area while realizing a uniform illuminance distribution in a predetermined range.

Further, since the light-shielding plate is provided inside the intermediate point of the pair of adjacent light sources, the illuminance distribution in a predetermined range can be made more uniform.

Further, since a reflector is provided on the outside of the light source row and the light-shielding plate is provided on the outside of the i-th light source excluding the first light source from the outside, the light emitted from the first light source from the outside is provided. A part of the light can be reflected by a reflector to irradiate the irradiation area.

Further, since the light-shielding plate extends in parallel with the light source row, the light-shielding plate can be commonly used for a plurality of light sources included in the light source row, and it is not necessary to provide a light-shielding plate for each light source.

It is a schematic diagram which shows the state which the lighting apparatus which concerns on 1st Embodiment of this invention is installed facing the work mounted on the mounting table, (a) is a perspective view, (b) is a front view. FIG. 1A is a schematic cross-sectional view taken along the line II-II. (A) is a graph showing the illuminance distribution of the lighting device shown in FIG. 1, and (b) is a graph showing the illuminance distribution of the conventional lighting device. The schematic sectional view of the lighting apparatus which concerns on 2nd Embodiment of this invention. The graph which shows the illuminance distribution of the lighting apparatus shown in FIG. (A) and (b) are graphs showing the illuminance distribution of the conventional lighting device, and (c) is a graph showing the ideal illuminance distribution.

[First Embodiment]
Hereinafter, the lighting device according to the first embodiment of the present invention will be described with reference to the accompanying drawings. As shown in FIG. 1, the lighting device 1 of the present embodiment is a planar lighting device that irradiates a work W mounted on a mounting table B with light from above, and is a lower side as shown in FIG. The housing 3 having an opening, the printed circuit board (hereinafter referred to as “board”) 5 housed and held in the housing 3, and the surface (lower surface) 51 of the substrate 5 are arranged in a two-dimensional matrix of n rows × m columns. A plurality of LEDs (light sources) 6 are provided. That is, FIG. 2 shows a single LED row extending in the X direction (first direction), and a plurality of such LED rows are arranged side by side in the Y direction. Further, a pair of reflectors 7 extending in the Y direction are erected on the outside of the LED column (LED matrix) in the X direction, and a light shielding plate 8 extending in the Y direction is provided between the LEDs 6 (LED rows) adjacent to the X direction. Multiple are provided.

With this configuration, a part of the light emitted from the LED 6 is absorbed by the light-shielding plate 8 and shielded from light, and the rest is directly or reflected by the reflector 7 to irradiate the mounting table B or the work W. By blocking a part of the light with the light-shielding plate 8 in this way, the amount of light irradiated to the region (hereinafter referred to as “outer region”) outside the irradiation region R corresponding to the width dimension of the work W in the X direction. Is reduced.

The light-shielding plate 8 will be described more specifically. In the following description, when the individual LEDs 6 or the light-shielding plate 8 are described, the reference numerals a, b, and c are added to distinguish them.

Each shading plate 8 is provided on the outside of the LED 6 corresponding to the i-th LED 6 from the outside in the X direction (hereinafter, simply referred to as “outside”), and is provided in the Z direction (second direction) from the surface 51 of the substrate 5 or its vicinity. It has been extended to. In the example shown in FIG. 2, the installation position of each light-shielding plate 8 is an intermediate position between a pair of adjacent LEDs 6 (LED row), and i> 1.

The light-shielding plate 8 installed in this way has an irradiation angle (hereinafter, "boundary irradiation angle") of the light emitted from the corresponding LED 6 and directed outward to the boundary between the irradiation region R and the outer region. By blocking light with an irradiation angle larger than (), the outer region is prevented from being irradiated with light.

For example, the light-shielding plate 8b installed outside the second (i = 2) LED 6b from the outside has an irradiation angle exceeding the boundary irradiation angle θb among the light emitted from the LED 6b and directed outward, that is, irradiation. By blocking the light outside the angle range θb, the light from the LED 6b is prevented from illuminating the outer region. Similarly, the light shielding plate 8c installed outside the third (i = 3) LED 6c from the outside is the light having an irradiation angle exceeding the boundary irradiation angle θc among the light emitted from the LED 6c and heading outward, that is, the light having an irradiation angle exceeding the boundary irradiation angle θc. By blocking the light outside the irradiation angle range θc, the light from the LED 6c is prevented from irradiating the outer region.

That is, the light outside the irradiation angle range θb in the LED 6b and the light outside the irradiation angle range θc in the LED 6c are the light emitted to the outer region if the light-shielding plates 8b and 8c are not provided, and by blocking these lights. The irradiation of light to the outer region is suppressed.

The value of the boundary irradiation angle can be calculated based on the distance from the end of the irradiation region R in the X direction to the LED 6 and the distance from the LED 6 to the upper surface of the work W in the Z direction (working distance), and each LED 6 ( It depends on each LED line). For example, in the example shown in FIG. 2, the boundary irradiation angle θb of the second LED 6b is about 27 °, and the boundary irradiation angle θc of the third LED 6c is about 44 °, which is inside in the X direction (hereinafter, simply “inside”). The boundary irradiation angle gradually increases toward the direction of). Further, the lower end position of each light-shielding plate 8 (height dimension of the light-shielding plate 8) is calculated based on the boundary irradiation angle in the corresponding LED 6 and the distance between the light-shielding plate 8 and the LED 6.

Here, by installing the light-shielding plate 8 so as to extend downward from the surface 51 of the substrate 5 or its vicinity as described above, each light-shielding plate 8 corresponds to the light emitted from the corresponding LED 6. Almost all light with an irradiation angle larger than the boundary irradiation angle (that is, light with a corresponding boundary irradiation angle to the maximum irradiation angle) can be shielded. The light-shielding plate 8 may be fixed to the substrate 5 or may be fixed to the housing 3.

FIG. 3A is a graph showing the first simulation result showing the illuminance distribution of the lighting device 1 of the present embodiment. In the graph, the X coordinate value = −420 corresponds to the position of the reflector 7 (indicated by the arrow A in FIG. 2). FIG. 3B is a graph showing simulation results showing the illuminance distribution when all the light-shielding plates 8 and the reflectors 7 are removed from the conventional lighting device, that is, the lighting device 1 of the present embodiment. From these simulation results, in the lighting device 1 of the present embodiment, there is less sagging in the illuminance distribution as compared with the conventional type, and an illuminance distribution close to the ideal illuminance distribution shown in FIG. 6 (c) can be obtained. You can see that.

As described above, in the present embodiment, by providing the light-shielding plate 8 that shields a part of the light from the LED 6 between the adjacent LEDs 6, the work W is irradiated with uniform light and protrudes from the work W. The amount of light emitted can be reduced.

[Second Embodiment]
Next, the lighting device according to the second embodiment of the present invention will be described. The lighting device 10 of the present embodiment shown in FIG. 4 is substantially the same as the above-mentioned lighting device 1, but the two outer light-shielding plates 8 (that is, the first and second light-shielding plates 8b', 8c from the outside). The position of') is set closer to the inside than the intermediate position of the pair of LEDs 6 adjacent to each other in the X direction, and the height of the light-shielding plates 8b'and 8c' is proportionally lowered. That is, the light-shielding plates 8b'and 8c' of the present embodiment have the same functions as the light-shielding plates 8b and 8c of the first embodiment, and the light-shielding plates 8b'and 8c' also have the same functions as the light-shielding plates 8b and 8c. Similarly, among the light emitted outward from the corresponding LEDs 6b and 6c, the light having an irradiation angle exceeding the boundary irradiation angle is blocked.

FIG. 5 is a graph showing a second simulation result showing the illuminance distribution of the lighting device 10 of the present embodiment. Compared with that of the first embodiment shown in FIG. 3A, the non-uniformity of the illuminance distribution at the end of the irradiation region R is eliminated.

The reason why the unevenness of the illuminance distribution is eliminated in this way is as follows. That is, the light-shielding plate 8 shields a part of the light emitted from the corresponding LED 6 located inside and toward the outside, but at the same time, the light-shielding plate 8 also blocks a part of the light emitted from the LED 6 located outside and toward the inside. Since it blocks light, this causes a decrease in illuminance and uniformity. Therefore, in the present embodiment, the light-shielding plates 8b', 8c'are deflected inward from those of the first embodiment to lower the height, so that the light-shielding plates 8b', 8c' are shielded inward. The amount of light is reduced to compensate for the decrease in illuminance and the decrease in uniformity caused by the light-shielding plate 8.

The lighting device according to the embodiment of the present invention has been described above with reference to the accompanying drawings, but the present invention is not limited to such an embodiment, and various modifications and modifications can be made without departing from the scope of the present invention. Is.

For example, in the above embodiment, the case where the present invention is applied to a planar lighting device in which a plurality of LEDs 6 are arranged in a two-dimensional matrix has been described, but the lighting device to which the present invention is applied is a planar lighting device. The present invention is not limited to, and can be applied to a linear illuminating device having only a single LED row.

In the above embodiment, the shading plate 8 is installed corresponding to all the LEDs 6 except the LEDs 6a located at both ends in the X direction, but the present invention is not limited to this, and at least one located in the region on both sides in the X direction. The light-shielding plate 8 may be installed in correspondence with the LED 6 (excluding the LED 6a). In particular, when the LED row is relatively long, the amount of light emitted from the LEDs 6 installed in the central region in the X direction reaches the outer region is extremely small, so that the light shielding plate 8 is used in the central region in the X direction. Even if it is omitted, the same effect as that of the above embodiment can be expected.

In the second embodiment, the installation positions of the two light-shielding plates 8 (8b', 8c') are adjusted inward, but the number of light-shielding plates 8 for adjusting the installation position inward is not limited to two. It may be one or three or more.

The LED 6 may be any type such as a white LED, an infrared LED, and a UV-LED. Further, the light in the present invention includes visible light, infrared light, UV light and the like, and the light shielding plate 8 is illuminated by absorbing UV light, white light, visible light, infrared light and the like to block light. It may be selectively used according to the application of the device 1 (10) and the type of the LED 6.

Further, in the above embodiment, a plurality of light-shielding plates 8 extending in the Y-direction are arranged side by side in the X-direction, but the light-shielding plates 8 may be provided in a grid pattern (a grid pattern). As a result, the light-shielding plate 8 is interposed between the pair of LEDs 6 adjacent in the X direction and also between the pair of LEDs 6 adjacent in the Y direction, and is interposed not only in the outer region in the X direction but also in the Y direction. The amount of light emitted to the outer region of the above can also be reduced.

1,10 Lighting device 5 Board 6 LED (light source)
7 Reflector 8 Light-shielding plate B Mounting table R Irradiation area W Work

Claims (4)

A lighting device for irradiating a predetermined irradiation area with light.
With the board
On the surface of the substrate, a light source sequence consisting of a plurality of light sources mounted at intervals in the first direction, and a light source sequence.
A plurality of light-shielding plates provided at intervals between the light sources in the light source row are provided.
Each of the light-shielding plates extends from the surface of the substrate or its vicinity in a second direction intersecting the surface of the substrate, and the irradiation angle of the light emitted from each light source toward the outside in the first direction is predetermined. To block light at angles deeper than the angle,
Further, by configuring the predetermined angle of the irradiation angle of each light-shielding plate to gradually increase inward in the first direction, at least a part of the light emitted from each light source beyond the predetermined irradiation region is emitted. Shade ,
In the first direction, the first light-shielding plate provided outside the second light source from the outside has an irradiation angle deeper than the first predetermined angle among the light emitted from the second light source. Block the light,
In the first direction, the second light-shielding plate provided outside the third light source from the outside has an irradiation angle deeper than the second predetermined angle among the light emitted from the third light source. Block the light,
The first predetermined angle is an irradiation angle of light emitted from the second light source and directed outward in the first direction, which is irradiated to the boundary between the predetermined irradiation region and the outer region. ,
The lighting device is characterized in that the second predetermined angle is an irradiation angle of light emitted from the third light source and directed outward in the first direction to the boundary . The lighting device according to claim 1, wherein the light-shielding plate is provided between a pair of adjacent light sources and inward in the first direction from an intermediate point of the pair of light sources. .. The claim is characterized in that, in the first direction, a reflector is provided on the outside of the light source row, and the light-shielding plate is provided on the outside of the i-th light source excluding the first light source from the outside. The lighting device according to 1 or 2. The light sources are arranged in a two-dimensional matrix.
Claims 1 to 1, wherein the light-shielding plate extends in a third direction orthogonal to the first direction in parallel with the light source line, corresponding to the i-th light source line from the outside in the first direction. The lighting device according to any one of 3.

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