JP2024093164A - Inspection Lighting System - Google Patents

Abstract

To enable a plurality of resistive elements to be distributedly located to the reverse side of an LED substrate in an illumination system for inspection that irradiates a workpiece surface with striped pattern light while shifting its phase.SOLUTION: Provided is an illumination system for inspection designed to irradiate a workpiece surface with striped pattern light while shifting its phase, said illumination system including an LED substrate on which a plurality of LED elements are mounted on one side in a matrix form and a plurality of resistive elements and a substrate-mounting connector are mounted on the reverse side. The LED substrate is divided into a plurality of areas in a plan view, and the substrate-mounting connector and the plurality of resistive elements are mounted in each divided area. In at least some of the plurality of divided areas, the arrangements of the substrate-mounting connector and the plurality of resistive elements mounted in adjacent areas, respectively, have a relationship of being rotated about 90° with respect to each other.SELECTED DRAWING: Figure 5

Description

The present invention relates to an inspection lighting system that irradiates a striped pattern of light onto the surface of a workpiece while shifting its phase.

In order to detect the surface shape of a workpiece, etc., an inspection lighting system is known that irradiates the surface of the workpiece with a striped pattern of light while shifting its phase (for example, Patent Document 1). Conventionally, in this inspection lighting system, multiple conductors are arranged to cross vertically and horizontally, and LED elements are connected to the intersections to arrange multiple LED elements in a matrix, and a controller is used to control the opening and closing of switching elements connected to each conductor, thereby generating a striped pattern of light and shifting its phase.

JP 2022-161985 A

In the inspection lighting system that irradiates the above-mentioned striped pattern light with phase shifting, multiple LED elements are mounted in a matrix on one side of the LED board, and multiple resistance elements that limit the current flowing through each LED element are mounted on the back side, and these are conductive through vias that penetrate the board. Furthermore, in this inspection lighting system, a buffer board equipped with multiple switching elements may be connected to the back side of the LED board, and in order to reduce power loss between the boards, a board-mounted connector may be mounted on the back side of the LED board and the buffer board may be connected to this board-mounted connector. However, this results in multiple resistance elements corresponding to multiple LED elements and board-mounted connectors being densely mounted on the back side of the LED board. This results in a location where the resistance elements are locally concentrated near the board-mounted connector, as shown in Figure 11, for example, and it becomes very difficult to handle the wiring because many vias need to be provided in the vicinity of that area.

The present invention was made to solve these problems, and its main objective is to enable multiple resistive elements to be distributed and arranged on the back side of an LED board in an inspection lighting system that irradiates a striped pattern of light onto the surface of a workpiece while shifting its phase.

That is, the inspection lighting system according to the present invention irradiates the surface of a workpiece with a striped pattern of light while shifting its phase, and is characterized in that it is equipped with an LED board having a matrix of multiple LED elements mounted on one side and a multiple resistance element and a board-mounted connector mounted on the back side, the LED board is divided into a multiple number of areas in a plan view, the board-mounted connector and the multiple resistance elements are mounted in each of the divided areas, and in at least some of the divided areas, the arrangement of the board-mounted connector and the multiple resistance elements mounted in adjacent areas are rotated by approximately 90 degrees from each other.

The present invention, configured in this way, makes it possible to disperse and arrange multiple resistive elements on the back side of the LED board in an inspection lighting system that irradiates the surface of a workpiece with a striped pattern of light while shifting its phase.

FIG. 1 is a diagram illustrating an overall configuration of an inspection illumination system according to an embodiment. FIG. 2 is a diagram illustrating a schematic configuration of an LED drive circuit of the inspection illuminator according to the embodiment. FIG. 2 is a diagram showing the configuration of an inspection illumination system according to the embodiment. FIG. 2 is a diagram showing a schematic configuration of the inspection illuminator according to the embodiment as viewed from the side; FIG. 4 is a diagram showing a schematic arrangement pattern on the rear side of an LED substrate of the inspection illuminator according to the embodiment; FIG. 13 is a diagram illustrating a schematic arrangement pattern on the rear surface side of an LED substrate of an inspection illuminator according to another embodiment. FIG. 13 is a diagram illustrating a schematic arrangement pattern on the rear side of an LED substrate of an inspection illuminator according to another embodiment. FIG. 13 is a diagram illustrating a schematic arrangement pattern on the rear side of an LED substrate of an inspection illuminator according to another embodiment. FIG. 13 is a diagram illustrating a schematic arrangement pattern on the rear side of an LED substrate of an inspection illuminator according to another embodiment. FIG. 13 is a diagram illustrating a schematic arrangement pattern on the rear side of an LED substrate of an inspection illuminator according to another embodiment. FIG. 13 is a diagram showing a schematic arrangement pattern on the rear side of an LED substrate of a conventional inspection illuminator.

Below, one embodiment of the inspection lighting system of the present invention will be described with reference to the drawings.

<Device Configuration>
The inspection illumination system 400 of this embodiment is used, for example, to detect the uneven shape of the surface of a workpiece W, and irradiates light in a striped pattern onto the surface of the workpiece W and shifts the phase of this striped pattern. The inspection illumination system 400 of this embodiment is configured so that the direction in which the light in the irradiated striped pattern is arranged and the transition direction thereof can be switched between vertical and horizontal, and is what is called two-axis phase-shift illumination.

Specifically, as shown in FIG. 1, the inspection lighting system 400 includes an inspection lighting device 100 having a light-emitting surface capable of emitting light in a striped pattern, a power supply device 200 that supplies power to the inspection lighting device 100, and a controller 300 that controls the light emission pattern of the inspection lighting device 100.

The inspection illuminator 100 includes an LED board 1 on which multiple LED elements 11 and multiple resistor elements 12 are mounted, and a buffer board 2 on which multiple switching elements 21 are mounted, which is arranged on top of the LED board 1.

The LED board 1 is a printed circuit board that is rectangular in plan view, and has multiple LED elements 11 arranged in a vertical and horizontal matrix on one surface (mounting surface). Each LED element 11 is a surface-mount type that emits light of any color tone, such as white light, and is arranged at equal pitches in the vertical and horizontal directions in plan view.

A number of resistor elements 12 are mounted on the back side of the LED substrate 1. The resistor elements 12 are intended to limit the current flowing through the LED elements 11, and one resistor element 12 is provided for each of the LED elements 11. Each resistor element 12 and each LED element 11 are connected in series with each other. The LED elements 11 and the resistor elements 12 are electrically connected by vias that penetrate the substrate.

The back side of the LED board 1 is also equipped with a board-mounted connector 13 that connects signals between boards. Specifically, this board-mounted connector 13 is also called a board-to-board connector, and has multiple connection pins (not shown) that fit into a printed circuit board. The buffer board 2 is attached to the LED board 1 by connecting it to the connection pins of this board-mounted connector 13 attached to the LED board 1, so that it is attached on top of the LED board 1.

The buffer substrate 2 is a printed circuit board arranged on the back side of the LED substrate 1, and is arranged so as to be overlapped (stacked) on the LED substrate 1. The buffer substrate 2 is provided with a plurality of switching elements 21 that open and close the circuits to which the LED elements 11 are connected. Examples of the switching elements 21 include, but are not limited to, field effect transistors such as MOSFETs. The plurality of buffer substrates 2 may have the same configuration. For example, the plurality of buffer substrates 2 may all be the same size, and may be equipped with the same number of elements of the same type in the same arrangement.

The circuit configuration of the inspection illuminator 100 of this embodiment will be described. As shown in FIG. 2, in this LED drive circuit 100C, multiple conductors are arranged to cross vertically and horizontally. The points where these vertically and horizontally arranged conductors cross each other are insulated. At each intersection of the horizontal conductors Y1 to Y6 and the vertical conductors X1 to X6, an LED element 11 and a resistor element 12 are connected in series. More specifically, one of the anode side and the cathode side of the LED element 11 is connected to the horizontal conductors Y1 to Y6, and the other is connected to the vertical conductors X1 to X6. A switching element 21 is connected to the end of each of the vertical conductors X1 to X6 and each of the horizontal conductors Y1 to Y6.

To emit light in a vertical striped pattern in such an LED drive circuit 100C, a signal is input to the switching elements 21 connected to the horizontal conductors to turn them all on, and the switching elements 21 connected to the vertical conductors are turned on, for example, every other one. Then, for example, by alternately switching on and off the switching elements 21 connected to the vertical conductors, the striped pattern can be shifted horizontally. By switching on and off the switching elements 21 between the vertical and horizontal directions, light can be emitted in a horizontal striped pattern, which can be shifted vertically.

The power supply unit 200 inputs a DC voltage to the LED drive circuit 100C of the inspection illuminator 100, and is specifically a CVCC power supply or the like.

The controller 300 controls the on/off of the switching element 21 provided in the inspection illuminator 100, and transmits a control signal that controls the on/off of the switching element 21 mounted on the buffer board 2 according to a predetermined pattern stored in advance.

In the inspection illuminator 100 of this embodiment, as shown in Figs. 3 and 4, the LED board 1 is divided into a plurality of areas in a plan view, and the buffer board 2 is connected to each of the areas. Specifically, in this inspection illuminator 100, the LED board 1 is divided into four areas, 2 vertical x 2 horizontal, and the buffer board 2 is connected to each area via the board-mounted connector 13. In other words, in this inspection illuminator 100, four board-mounted connectors 13 are mounted on the back surface of one LED board 1, and four buffer boards 2 are connected via these board-mounted connectors 13. Each buffer board 2 is provided with a plurality of switching elements 21 that open and close the vertical or horizontal multiple conductors provided in each corresponding area. In addition, the plurality of LED elements 11 arranged in a matrix on the front side of the LED board 1 are also evenly arranged in these four areas.

In this embodiment, each buffer board 2 is equipped with a communication IC 22, and the controller 300 is configured to transmit a control signal for controlling the on/off of the switching element 21 to the communication IC 22 of each buffer board 2 by differential communication. Furthermore, in this embodiment, each buffer board 2 is equipped with a DC/DC converter 23 that reduces the DC voltage (24 V in this case) supplied from the power supply device 200 to a predetermined DC voltage (3.6 V in this case), and the DC voltage supplied from the power supply device 200 is applied to the LED drive circuit 100C after the voltage value is reduced in the buffer board 2.

In the inspection illuminator 100 of this embodiment, in order to disperse and arrange the multiple resistive elements 12 on the back side of the LED board 1, as shown in FIG. 5, a board-mounted connector 13 and multiple resistive elements 12 are mounted on each divided area of the LED board 1. In at least some of the divided areas, the board-mounted connectors 13 and multiple resistive elements 12 mounted on adjacent areas are rotated by approximately 90° relative to each other.

In this embodiment, in all four areas, the arrangement of the board-mounted connector 13 and the multiple resistance elements 12 mounted in each adjacent area is rotated by about 90 degrees relative to each other. More specifically, when proceeding clockwise through the four areas, the arrangement of the board-mounted connector 13 and the resistance elements 12 in each area is rotated clockwise by about 90 degrees. In other words, the arrangement of the board-mounted connector 13 and the resistance elements 12 in each area is rotationally symmetrical to each other. Here, in all four areas, the elongated board-mounted connector 13 is parallel along the vertical or horizontal direction and is arranged close to the center of the LED board 1. Then, in each area, the multiple resistance elements 12 are arranged in multiple rows along a direction perpendicular to the direction in which the board-mounted connector 13 extends. Furthermore, here, each resistance element 12 is elongated, and in each area, the multiple resistance elements 12 are mounted so that their longitudinal direction coincides with the longitudinal direction of the board-mounted connector 13.

In each area, the board-mounted connectors 13 are arranged so as to span multiple vertical or horizontal conductors. For example, in FIG. 5, the board-mounted connectors 13 in the top right area of the LED board 1 span the horizontal conductors Y1 to Y3, the board-mounted connectors 13 in the top left area span the vertical conductors X1 to X3, the board-mounted connectors 13 in the bottom left area span the horizontal conductors Y4 to Y6, and the board-mounted connectors 13 in the bottom right area span the vertical conductors X4 to X6.

Next, the configuration of this embodiment that enables the arrangement of the board-mounted connectors 13 and resistor elements 12 in each area will be described. In the inspection illuminator 100 of this embodiment, the orientation of the LED elements 11 mounted on the LED board 1 is changed for each area, and the connection order of the corresponding LED elements 11 and resistor elements 12 is changed for each area.

Specifically, as shown in FIG. 5, the orientation of the multiple LED elements 11 in each area (the orientation in which the anode electrode 11a and the cathode electrode 11b are aligned) is aligned differently from the orientation of the LED elements 11 in other adjacent areas (rotated by approximately 90 degrees). Here, the multiple LED elements 11 are arranged horizontally in the upper right and lower left areas of the LED board 1, and the multiple LED elements 11 are arranged vertically in the adjacent upper left and lower right areas.

As shown in FIG. 2, the connection order of the LED elements 11 and the corresponding resistor elements 12 in each area is the same, and the connection order of the LED elements 11 and resistor elements 12 in other adjacent areas is reversed. Here, the LED elements 11 and resistor elements 12 are connected in series in this order in the upper right and lower left areas of the LED board 1, and the LED elements 11 and resistor elements 12 are connected in series in the reverse order in the adjacent upper left and lower right areas.

<Action and effect>
According to the inspection lighting system 400 of the present embodiment configured as described above, the LED board 1 is divided into a plurality of areas, the board-mounted connectors 13 and the plurality of resistive elements 12 are distributed among the areas, and further, the arrangements of the board-mounted connectors 13 and the plurality of resistive elements 12 are rotated by 90° between at least some adjacent areas, so that it is possible to distribute the locations on the back surface of the LED board 1 where the arrangement of the resistive elements 12 would be dense due to the presence of the board-mounted connectors 13. This makes it possible to distribute the locations where vias are densely packed, making it easier to manage the wiring.

<Other embodiments>
The present invention is not limited to the above-described embodiment.
For example, in another embodiment, as shown in FIG. 6 , the elongated board-mounted connectors 13 in each area may be arranged parallel to the vertical or horizontal direction and close to the outer edge of the LED board 1.

In the above embodiment, the arrangement of the board-mounted connectors 13 and the resistive elements 12 in each area are rotationally symmetrical to each other, but this is not limited to the above. In other embodiments, as shown in FIG. 7, the arrangement of the board-mounted connectors 13 and the resistive elements 12 in each area may rotate counterclockwise by approximately 90° as one progresses clockwise through the four areas. Also, as shown in FIG. 8, in each area, the multiple resistive elements 12 may be mounted so that their longitudinal direction is perpendicular to the longitudinal direction of the board-mounted connectors 13.

Furthermore, in the above embodiment, in all four areas, the arrangement of the board-mounted connector 13 and the multiple resistive elements 12 mounted in each adjacent area is rotated by approximately 90 degrees relative to each other, but this is not limited to this. In other embodiments, as shown in FIG. 9, in some of the multiple areas (here, the upper right, upper left, and lower right areas), the arrangement of the board-mounted connector 13 and the multiple resistive elements 12 may be rotated by approximately 90 degrees with respect to the arrangement in the adjacent areas.

In another embodiment, as shown in FIG. 10, one board-mounted connector 13 may be provided across multiple areas. Even in such a case, the effects of the present invention can be achieved by rotating the arrangement of the board-mounted connector 13 and multiple resistive elements 12 in some areas (here, the upper right and lower right) by approximately 90 degrees relative to the arrangement in the adjacent areas.

In the above embodiment, each buffer board 2 is equipped with a communication IC 22, and a control signal is transmitted between the buffer board 2 and the controller 300 by differential communication, but this is not limited to the above. In other embodiments, each buffer board 2 may not be equipped with a communication IC 22. Furthermore, each buffer board 2 may not be equipped with a DC/DC converter 23.

In addition, in the above embodiment, multiple buffer substrates 2 are provided for one LED substrate 1, but this is not limited to the above. In other embodiments, one buffer substrate 2 may be provided for one LED substrate 1.

In addition, the board-mounted connector 13 in the above embodiment is a board-to-board connector that can be connected to both the LED board 1 and the buffer board 2 via connection pins or the like, but is not limited to this. In other embodiments, the board-mounted connector 13 may be a connector to which a flat cable, flexible board, or the like is connected.

The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the invention. For example, the disclosure of this specification includes the following aspects 1 to 6.

(Aspect 1)
An inspection lighting system which illuminates the surface of a workpiece with a striped pattern of light while shifting its phase, and which comprises an LED board having a plurality of LED elements mounted in a matrix on one side and a plurality of resistive elements and a board-mounted connector mounted on the back side thereof, wherein the LED board is divided into a plurality of areas in a plan view, the board-mounted connector and the plurality of resistive elements are mounted in each of the divided areas, and in at least some of the divided areas, the arrangement of the board-mounted connector and the plurality of resistive elements mounted in adjacent areas are rotated by approximately 90 degrees from each other.

In this manner, the LED board is divided into multiple areas, the board-mounted connector and multiple resistive elements are distributed among the areas, and the board-mounted connector and multiple resistive elements are arranged in a 90° rotated relationship between at least some adjacent areas. This allows the areas on the back surface of the LED board where the resistive elements would be densely packed due to the presence of the board-mounted connector to be dispersed. This allows the areas where vias are densely packed to be dispersed, making it easier to route the wiring.

(Aspect 2)
The inspection lighting system described in aspect 1, wherein the LED board is divided into four areas, 2 vertically and 2 horizontally, and in all of the four areas, the arrangement of the board-mounted connectors and the multiple resistive elements mounted in adjacent areas are rotated approximately 90° from each other.
With this configuration, in all divided areas, the arrangement of the board-mounted connector and the multiple resistive elements between adjacent areas can be rotated 90 degrees relative to each other, thereby further reducing the number of areas where the resistive elements are densely arranged.

(Aspect 3)
The inspection lighting system according to claim 2, wherein the arrangement of the board-mounted connectors and the plurality of resistive elements mounted in each of the four areas are rotationally symmetrical with respect to each other.
With this configuration, a plurality of board-mounted connectors can be evenly arranged on the back side of the LED board, further reducing the number of locations where the resistive elements are densely arranged.

(Aspect 4)
An inspection lighting system according to any one of aspects 1 to 3, wherein the orientation of the LED elements in each area is aligned, and the orientations of the LED elements in adjacent areas are different from each other.
With this configuration, the above-mentioned arrangement of the board-mounted connector and the plurality of resistive elements can be realized.

(Aspect 5)
An inspection lighting system described in any one of aspects 1 to 4, wherein the connection order of the multiple LED elements and the corresponding multiple resistance elements in each area is the same, and the connection orders of the multiple LED elements and the multiple resistance elements in adjacent areas are opposite to each other.
In this manner, the above-mentioned arrangement of the board-mounted connector and the plurality of resistor elements can be realized. Furthermore, the problem of having to partially thin the board wiring due to the dense arrangement of the resistor elements does not occur, and the entire board can be configured with thick wiring, and the wiring pattern design can be simplified.

(Aspect 6)
An inspection illumination system according to any one of aspects 1 to 5, configured so that the direction in which the light of the irradiated stripe pattern is arranged and its transition direction can be switched between vertical and horizontal.

400... Inspection lighting system 1... LED board 11... LED element 12... Resistance element 13... Board-mounted connector W... Work

Claims (6)

A stripe pattern of light is irradiated onto the surface of a workpiece while shifting the phase of the light,
an LED board having a plurality of LED elements mounted in a matrix on one surface thereof and a plurality of resistor elements and a board-mounted connector mounted on a rear surface thereof;
The LED board is divided into a plurality of areas in a plan view, and the board-mounted connector and the plurality of resistance elements are mounted on each of the divided areas,
An inspection lighting system in which, in at least some of the multiple divided areas, the arrangement of the board-mounted connectors and multiple resistive elements mounted in adjacent areas are rotated approximately 90 degrees from each other. The LED board is divided into four areas, 2 vertically and 2 horizontally.
The inspection lighting system of claim 1, wherein in all of the four areas, the arrangement of the board-mounted connectors and the plurality of resistive elements mounted in adjacent areas are rotated approximately 90 degrees from each other. The inspection lighting system according to claim 2, wherein the arrangement of the board-mounted connectors and the plurality of resistive elements mounted in each of the four areas are rotationally symmetrical with respect to each other. The inspection lighting system of claim 1, in which the orientation of the LED elements in each area is the same, and the orientation of the LED elements in adjacent areas is different from each other. The inspection lighting system according to claim 4, in which the connection order between the LED elements and the corresponding resistor elements in each area is the same, and the connection orders between the LED elements and the resistor elements in adjacent areas are reversed. The inspection lighting system according to claim 1, configured so that the direction in which the light of the striped pattern is irradiated and its transition direction can be switched between vertical and horizontal.