JP7065756B2 - Lighting equipment - Google Patents

Description

The present invention relates to a lighting device.

Conventionally, there is a surface inspection system for inspecting the surface of a work having a sheet-like or flat plate-like shape and inspecting the flatness (deformation) thereof. As shown in Patent Document 1, this surface inspection system projects a light-dark pattern in which bright parts and dark parts are alternately repeated on a work, images the work with an image pickup device, and uses the image data obtained by the projection. The surface of the work is inspected. The above-mentioned light-dark pattern is formed by a slit member provided between the light source and the work. In this slit member, a band-shaped translucent portion and a band-shaped light-shielding portion are alternately formed by providing a light-shielding region portion on a light-transmitting base material made of resin.

However, in the case of forming a light / dark pattern by partially blocking the light from the light source as described above, the light of the light source cannot be effectively used, which causes a decrease in the amount of light, and the contrast of the light / dark pattern. Becomes weaker. Then, it becomes difficult to improve the accuracy when performing a surface inspection or the like using the image data obtained by the image pickup apparatus.

Japanese Unexamined Patent Publication No. 2013-140050

Therefore, the main object of the present invention is to increase the contrast of the light-dark pattern and to form a striped pattern close to an ideal square wave or an ideal sine wave.

That is, in the lighting device according to the present invention, the rectangular chambers having a rectangular shape in a plan view having a light emission port on the upper surface are arranged in a matrix in the horizontal direction and the vertical direction, and the first small chamber is on the center line in the horizontal direction in each of the small chambers. An LED is arranged, and a second LED is arranged on a center line in the vertical direction. By selectively lighting the first LED or the second LED, a straight line along the horizontal direction or the vertical direction is arranged. It is characterized by forming at least a striped pattern in which bright and dark parts are alternately repeated.

In such a lighting device, since the first LED is arranged on the center line in the horizontal direction in the small chamber, the light amount distribution of the light emission port in the small chamber can be illuminated so as to be symmetrical in the horizontal direction. Further, since the second LED is arranged on the center line in the vertical direction in the small chamber, the light amount distribution of the light emission port can be illuminated so as to be symmetrical in the vertical direction. As a result, it is possible to eliminate the asymmetry of the light amount distribution in the lateral direction in one row of bright parts when a striped pattern in which linear bright parts and dark parts are alternately repeated is formed, which is an ideal rectangular shape. It is possible to form a striped pattern close to a wave or an ideal sine wave. In addition, since it is configured to selectively illuminate only the necessary LEDs, the light from the light source can be effectively utilized and the amount of light is reduced as compared with the configuration in which a light-dark pattern is formed by partially blocking the light from the light source. Can be reduced. Further, since the LEDs forming the striped pattern are arranged on a straight line, the circuit configuration thereof can be simplified.

Here, in order to further enhance the contrast between the bright part and the dark part, it is desirable that the inner surface of the small chamber is a reflective surface.

In order to make the light amount distribution of the light emission port the same and the spacing of the striped patterns the same between the case where the horizontal striped pattern is formed and the case where the vertical striped pattern is formed, the small chamber is viewed in a plan view. It is desirable to have a square shape.

At this time, it is desirable that the number of the first LED and the second LED arranged in the small chamber is the same.

In order to reduce the unevenness of the amount of light in the longitudinal direction of the bright portion, the plurality of the first LEDs on the horizontal center line are arranged at equal intervals from each other, and the plurality of LEDs on the vertical center line are arranged at equal intervals. It is desirable that the second LEDs are arranged at equal intervals from each other.

The first LED and the second LED have a square shape in a plan view, and one diagonal line of the first LED is arranged so as to be located on the center line in the lateral direction, and the second LED is arranged. It is desirable that one of the diagonal lines of the LED is arranged so as to be located on the center line in the vertical direction.

Further, in the lighting device according to the present invention, rectangular chambers having a rectangular shape in a plan view having a light ejection port on the upper surface are arranged in a matrix in the horizontal and vertical directions, and are arranged in a plurality of chambers arranged in the vertical direction. A plurality of LEDs are provided in a staggered manner so as to be equidistant from the horizontal center line in the plurality of chambers arranged in the vertical direction, and the plurality of LEDs arranged in the plurality of chambers arranged in the horizontal direction. However, the plurality of chambers arranged in the horizontal direction are provided in a staggered manner at equal distances from the center line in the vertical direction, and by selectively lighting the plurality of LEDs, the row direction or the column direction is provided. It is characterized in that at least a striped pattern in which linear bright parts and dark parts are alternately repeated along the above is formed.

In such a lighting device, a plurality of LEDs arranged in a plurality of vertically arranged chambers are staggered so as to be equidistant from the horizontal center line in the plurality of vertically arranged chambers. Since it is provided, the bright part can be made uniform as a whole when a striped pattern in which linear bright parts and dark parts are alternately repeated along the vertical direction is formed. Further, since the plurality of LEDs arranged in the plurality of chambers arranged in the horizontal direction are provided in a staggered manner so as to be equidistant from the center line in the vertical direction in the plurality of chambers arranged in the horizontal direction, the horizontal direction is provided. When a striped pattern in which linear bright parts and dark parts are alternately repeated along a direction is formed, the bright parts can be made uniform as a whole. As a result, a striped pattern close to an ideal square wave or an ideal sine wave can be formed.

According to the present invention configured as described above, the contrast of the light-dark pattern can be strengthened, and a striped pattern close to an ideal square wave or an ideal sine wave can be formed.

It is a perspective view which shows the usage method of the lighting apparatus of this embodiment. It is a top view of the lighting apparatus of the same embodiment. It is sectional drawing of the lighting apparatus of the same embodiment. It is a figure for demonstrating the arrangement mode of LED in the small room of the same embodiment. It is a figure which shows an example of the circuit structure of the lighting apparatus of the same embodiment. It is a schematic diagram which shows the lighting mode of the lighting apparatus of the same embodiment. It is a schematic diagram which shows the lighting mode of the lighting apparatus of the same embodiment. It is a top view of the lighting apparatus of a modified embodiment. It is a top view of the lighting apparatus of a modified embodiment. It is a top view of the lighting apparatus of a modified embodiment.

Hereinafter, an embodiment of the lighting device according to the present invention will be described with reference to the drawings.

As shown in FIG. 1, the lighting device 100 of the present embodiment is used for a surface inspection system Z for inspecting the surface of a work W having a sheet shape or a flat plate shape and inspecting the flatness thereof. In this surface inspection system Z, a lighting device 100 that illuminates a work W with a striped pattern (bright / dark pattern) P in which linear bright portions P1 and dark portions P2 are alternately repeated, and a work W illuminated by the lighting device 100. It includes an image pickup device 200 for taking an image and a processing device 300 for processing the image data obtained by the image pickup device 200. The surface inspection system Z in FIG. 1 is a reflection type that captures the light reflected by the work W, but when the work W has light transmission, the light transmitted through the work W It may be a transmissive type that captures an image.

Specifically, as shown in FIGS. 2 and 3, the lighting device 100 has a rectangular chamber 10 in a plan view having a light emitting port on the upper surface and a reflecting surface on the inner side surface in a matrix shape in the horizontal direction and the vertical direction. Aligned with. A first LED 2 and a second LED 3 are provided in each of these small chambers.

The small chamber 10 of the present embodiment has a square shape in a plan view, and the entire upper surface has a square-shaped light ejection port in a plan view. The small chamber 10 is formed by partitioning the internal space of the housing 4, which has a substantially rectangular parallelepiped shape of the lighting device 100, by a plurality of partition walls 5 provided in a grid pattern in the vertical and horizontal directions. Both sides of the partition wall 5 are reflective surfaces. Further, a diffusion plate 6 is provided in the upper surface opening of the housing 4 so as to cover the light emission port of the small chamber 10.

As shown in FIG. 4, the first LED 2 is arranged on the horizontal center line L1 in each of the small chambers 10, and the second LED 3 is arranged on the vertical center line L2. The horizontal center line L1 is a line passing through the center of the small chamber 10 in the horizontal direction, and the vertical center line L2 is a line passing through the center of the small chamber in the vertical direction. Here, the fact that the LEDs 2 and 3 are arranged on the center lines L1 and L2 is limited to the fact that the light emitting center of the LEDs 2 and 3 (for example, the center of the light emitting surface) is located on the center lines L1 and L2. However, in the case of the first LED2, the position may be such that the light amount distribution in the lateral direction at the light emission port of the small chamber 10 is substantially symmetrical with respect to the center line L1, and in the case of the second LED3. The position is such that the vertical light amount distribution at the light emission port of the small chamber 10 is substantially symmetrical with respect to the center line L2.

In the present embodiment, the first LED2 and the second LED3 have a square shape in a plan view, and one diagonal line of the first LED2 is arranged so as to be located on the horizontal center line L1. One diagonal line of LED 3 of 2 is arranged so as to be located on the center line L2 in the vertical direction.

The number of the first LED2 and the second LED3 arranged in each small chamber 10 is the same, and the number is two in the present embodiment, but the number is not limited to this. The first LED 2 and the second LED 3 are of the same type, and may be, for example, an LED chip itself, a surface mount type or a bullet type LED package, or a large number of LEDs. It may be a COB type (Chip On Board) in which the chip is mounted on a metal substrate or the like.

Further, in the plurality of small chambers 10 arranged in the vertical direction, the plurality of first LEDs 2 on the center line L1 in the horizontal direction are arranged at equal intervals from each other. In the plurality of small chambers 10 arranged in the horizontal direction, the plurality of second LEDs 3 on the center line L2 in the vertical direction are arranged at equal intervals from each other. Further, in the present embodiment, the arrangement interval of the first LED2 and the arrangement interval of the second LED3 are the same.

Here, an example of the circuit configuration of the lighting device 100 is shown in FIG.

A plurality of first LEDs 2 arranged in the vertical direction are connected in series with each other. The series circuit unit 20 of the plurality of first LEDs 2 arranged in the vertical direction is connected in parallel with the series circuit unit 20 of the other first LEDs 2. Specifically, the series connection portion 20 of the first LED 2 is divided into two circuit portions, and the series connection portions 20 adjacent to each other are connected so as to be different circuit portions. In FIG. 5, assuming that the first, second, ..., And eighth series circuit units 20 are taken from the left side, the first, third, fifth, and seventh series circuit units 20 are connected in parallel to form one circuit. The second, fourth, sixth, and eighth series circuit units 20 are connected in parallel to form one circuit unit. The two circuit units have power supply connection terminals CH1 and CH2, respectively.

Further, the plurality of second LEDs 3 arranged in the horizontal direction are connected in series with each other. The series circuit unit 30 of the plurality of second LEDs 3 arranged in the horizontal direction is connected in parallel with the series circuit unit 30 of the other second LEDs 3. Specifically, the series connection portion 30 of the second LED 3 is divided into two circuit portions, and the series connection portions 30 adjacent to each other are connected so as to be different circuit portions. In FIG. 5, assuming that the upper series circuit unit 30 is the first, second, ..., Eighth series circuit unit 30, the first, third, fifth, and seventh series circuit units 30 are connected in parallel. The second, fourth, sixth, and eighth series circuit units 30 are connected in parallel to form one circuit unit. The two circuit units have power supply connection terminals CH3 and CH4, respectively.

Next, the lighting mode of the lighting device 100 configured as described above will be described.

In the lighting device 100 of the present embodiment, by selectively lighting the first LED2 or the second LED3, linear bright portions P1 and dark portions P2 along the horizontal or vertical direction are alternately repeated. At least the pattern P is formed.

Specifically, as shown in FIG. 6, among the series connection portions 20 of the first LED2, by supplying power to one channel (CH1 or CH2), a linear bright portion P1 along the vertical direction is formed. The dark portion P2 and the dark portion P2 alternately form a striped pattern P. Here, by switching between CH1 and CH2, the bright part P1 and the dark part P2 are inverted.

Further, as shown in FIG. 7, by supplying power to one of the channels (CH3 or CH4) of the series connection portion 30 of the second LED3, the linear bright portion P1 and the dark portion P2 along the lateral direction are formed. Form a striped pattern P that repeats alternately. Here, by switching between CH3 and CH4, the bright part P1 and the dark part P2 are inverted.

It should be noted that these lighting modes are switched, for example, by switching the power supply connection terminals CH1 to CH4 that supply power to the power cable 7 provided with the power supply connection terminals CH1 to CH4. For example, it may be performed by switching the power supply connection terminals CH1 to CH4 connected to the power supply device (not shown), or all the power supply connection terminals CH1 to CH4 are connected to the power supply device and power is supplied on the power supply device side. You may switch the connection terminal. In addition, a changeover switch may be provided on the lighting device side so as to be switched by the changeover switch.

According to the lighting device 100 of the present embodiment configured in this way, since the first LED2 is arranged on the horizontal center line L1 in the small chamber 10 whose inner side surface is a reflective surface, the first LED2 is arranged along the vertical direction. When the linear bright portion P1 and the dark portion P2 alternately repeat to form a striped pattern P, the light emission port can be uniformly illuminated. At this time, the light amount distribution of the light emission port becomes symmetrical in the horizontal direction (see FIG. 6). Further, since the second LED3 is arranged on the center line L2 in the vertical direction in the small chamber 10 whose inner side surface is a reflective surface, the linear bright part P1 and the dark part P2 along the horizontal direction alternate. When the repeating striped pattern P is formed, the light emission port can be uniformly illuminated. At this time, the light amount distribution of the light emission port becomes symmetrical in the vertical direction (see FIG. 7). As a result, it is possible to eliminate the asymmetry of the light amount distribution in the lateral direction in one row of bright parts when forming a striped pattern in which linear bright parts and dark parts alternate, thereby forming an ideal rectangular shape. A striped pattern P close to a wave or an ideal sine wave can be formed. Further, since the configuration is such that only the necessary LED 3 is selectively illuminated, the light of the light source can be effectively utilized and the amount of light is reduced as compared with the configuration in which the light and dark pattern is formed by partially blocking the light from the light source. Can be reduced. Further, since the first LED2 and the second LED3 forming the striped pattern P are arranged on a straight line, the circuit configuration thereof can be simplified.

The present invention is not limited to the above embodiment.

For example, the number and arrangement pattern of the first LEDs 2 arranged in the small chamber 10 and the number and arrangement patterns of the second LEDs 3 can be variously changed as shown in FIG. 8 and the like in addition to the above-described embodiment. .. FIG. 8 shows an example in which the numbers of the first LED 2 and the second LED 3 are different, and two first LEDs 2 are arranged and three second LEDs 3 are arranged. In this example, one of the second LEDs 3 is provided not only on the vertical center line L2 but also on the horizontal center line L1, but the present invention is not limited to this. Further, the number of the first LED 2 or the second LED 3 may be one, or may be three or more.

Further, although the small chamber 10 of the embodiment has a square shape in a plan view, it may have a rectangular shape in a plan view as shown in FIG. In this case, the arrangement pattern of the first LED 2 and the arrangement pattern of the second LED 3 may or may not be rotationally symmetric. Further, the number may be the same or different.

Further, as shown in FIG. 10, the plurality of LEDs 2 arranged in the plurality of vertically arranged chambers 10 are equidistant from the horizontal center line L1 in the plurality of vertically arranged chambers 10. A plurality of LEDs 3 arranged in a staggered pattern and arranged in a plurality of small chambers 10 arranged in the horizontal direction are staggered so as to be equidistant from the center line L2 in the vertical direction in the plurality of small chambers 10 arranged in the horizontal direction. It may be provided in a shape. Even with such an arrangement, by selectively lighting a plurality of LEDs 2 and 3, a striped pattern P in which linear bright portions P1 and dark portions P2 along the row direction or the column direction alternately repeat is formed. can do.

In the lighting device 100, the plurality of LEDs 2 arranged in the plurality of vertically arranged chambers are staggered so as to be equidistant from the horizontal center line L1 in the plurality of vertically arranged chambers 10. In the case of forming a striped pattern in which linear bright portions P1 and dark portions P2 alternately repeat along the vertical direction, the bright portions P1 can be made uniform as a whole. Further, the plurality of LEDs 3 arranged in the plurality of small chambers 10 arranged in the horizontal direction are provided in a staggered manner so as to be equidistant from the center line L2 in the vertical direction in the plurality of small chambers 10 arranged in the horizontal direction. Therefore, when a linear bright portion P1 and a dark portion P2 along the lateral direction alternately repeat a striped pattern, the bright portion P1 can be made uniform as a whole. As a result, a striped pattern close to an ideal square wave or an ideal sine wave can be formed.

The lighting pattern of the lighting device 100 is not limited to the configuration in which the bright part and the dark part are alternately repeated at equal intervals periodically as in the above embodiment. For example, the total number of the first LEDs 2 and the second LED 2 can be set by the user or the like. You may turn on all of the LEDs 3 of the above, or you may change the width of the bright part or the dark part by turning on or off the LED rows adjacent to each other at the same time.

In the above embodiment, the inner surface of the small chamber is used as a reflecting surface, but it does not have to be a reflecting surface.

In addition, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

100 ・ ・ ・ Lighting device 10 ・ ・ ・ Small room L1 ・ ・ ・ Horizontal center line 2 ・ ・ ・ First LED
L2 ・ ・ ・ Vertical center line 3 ・ ・ ・ Second LED
P1 ・ ・ ・ Bright part P2 ・ ・ ・ Dark part

Claims (6)

The rectangular chambers having a light emission port on the upper surface are arranged in a matrix in the horizontal and vertical directions.
In each of the small chambers, the first LED is arranged on the horizontal center line, and the second LED is arranged on the vertical center line.
A lighting device that selectively lights the first LED or the second LED to form at least a striped pattern in which linear bright and dark portions are alternately repeated along a horizontal or vertical direction. The lighting device according to claim 1, wherein the small chamber has a square shape in a plan view. The lighting device according to claim 1 or 2, wherein the number of the first LED and the second LED arranged in the small chamber is the same. The plurality of the first LEDs on the horizontal center line are arranged at equal intervals from each other.
The lighting device according to any one of claims 1 to 3, wherein the plurality of second LEDs on the center line in the vertical direction are arranged at equal intervals from each other. The first LED and the second LED have a square shape in a plan view.
One diagonal of the first LED is arranged so as to be located on the lateral center line.
The lighting device according to any one of claims 1 to 3, wherein one diagonal line of the second LED is arranged so as to be located on the center line in the vertical direction. The rectangular chambers having a light emission port on the upper surface are arranged in a matrix in the horizontal and vertical directions.
A plurality of LEDs arranged in a plurality of vertically arranged chambers are provided in a staggered manner so as to be equidistant from the horizontal center line in the plurality of vertically arranged chambers.
A plurality of LEDs arranged in a plurality of chambers arranged in the horizontal direction are provided in a staggered manner so as to be equidistant from the center line in the vertical direction in the plurality of chambers arranged in the horizontal direction.
A lighting device that selectively turns on the plurality of LEDs to form at least a striped pattern in which linear bright and dark areas are alternately repeated along a row direction or a column direction.

Images