Lighting system for inspection

Abstract

This lighting system for inspection has one light-emitting surface that emits light in prescribed patterns and irradiates the surface of a workpiece with the light while causing the light to transition between the prescribed patterns. The lighting system for inspection comprises: a plurality of LED modules that each have an LED substrate having a plurality of LED elements mounted thereon, and are arranged side by side to form the one light-emitting surface; and a trigger output unit that outputs, to the plurality of LED modules, a trigger signal for commanding a transition between the prescribed patterns. Each of the plurality of LED modules: stores, in advance, lighting patterns that indicate transitions between light emission modes of the plurality of LED elements; and upon reception of the trigger signal, switches the light emission modes of the plurality of LED elements in accordance with the lighting patterns.

Description

Inspection lighting system

[0007] ,

[0006] ,

[0001] The present invention relates to an inspection lighting system that irradiates the surface of a workpiece while transitioning light of a predetermined pattern.

[0002] For detecting the surface shape of a workpiece, for example, an inspection lighting system that irradiates the surface of the workpiece while transitioning the phase of light in a stripe pattern is known (for example, Patent Document 1). In this inspection lighting system, a plurality of conductive wires are provided so as to intersect vertically and horizontally, and a plurality of LED elements are arranged in a matrix by connecting LED elements at the intersection positions, and the switching elements connected to each conductive wire are controlled to be opened and closed by a controller. By doing so, light in a stripe pattern can be generated and the phase can be transitioned.

[0003] Japanese Patent Application Laid-Open No. 2022-161985

[0004] By the way, in an inspection lighting system that irradiates light in a stripe pattern with a phase transition as described above, a high degree of freedom in customization is required so that the size of the light emitting surface and the light emitting pattern can be changed according to the size of the workpiece to meet various applications.

[0005] Therefore, the inventor considered configuring one inspection lighting system by arranging a plurality of LED modules side by side. If it is such a thing, the size of the light emitting surface can be freely changed by changing the number of LED modules to be combined. Also, by changing the light emitting pattern of each LED module, the overall light emitting pattern can be changed.

[0006] However, the problem here is that when the light emitting patterns are the same in all LED modules, it is impossible to handle light emitting patterns that span multiple LED modules. Also, when sending individual light emitting pattern data to all LED modules, the data volume increases every time the number of LED modules increases, resulting in a response delay in data transfer. Such a problem is not limited to the case of transitioning light in a stripe pattern, but the same can be said for the case of transitioning light of various patterns.

[0007] The present invention has been made in view of these problems, and its main objective is to provide an inspection lighting system that illuminates a workpiece while transitioning between predetermined patterns of light, while suppressing response delays due to data transmission and increasing the degree of freedom in customizing the size of the light-emitting surface and the light-emitting pattern.

[0008] In other words, the inspection lighting system according to the present invention has a light-emitting surface that emits light in a predetermined pattern, and irradiates the surface of a workpiece while transitioning the light of the predetermined pattern, and comprises a plurality of LED modules having an LED substrate on which a plurality of LED elements are mounted, and which are arranged in a row to form one of the light-emitting surfaces, and a trigger output unit that outputs a trigger signal to the plurality of LED modules that commands the transition of the predetermined pattern, and each of the plurality of LED modules individually stores a lighting pattern that indicates the transition of the light-emitting mode of the plurality of LED elements, and when it receives the trigger signal it switches the light-emitting mode of the plurality of LED elements in accordance with the lighting pattern.

[0009] With this configuration, multiple LED modules are arranged in a row to form a single light-emitting surface. By changing the number and arrangement of the LED modules, the size of the light-emitting surface and the light-emitting pattern can be freely altered. Furthermore, each of the multiple LED modules individually stores the lighting pattern of its LED elements, and the controller can transition the pattern light simply by outputting a trigger signal to each LED module. Therefore, compared to a system where the lighting patterns are stored in the controller and control signals to control the light emission of the LED elements are transmitted from the controller to each LED module, the response speed can be significantly faster. Even if the number of LED modules increases, the transition of the predetermined light pattern can be achieved with high responsiveness to the trigger.

[0010] A specific embodiment of the inspection lighting system is one in which, each of the plurality of LED modules receives the trigger signal, sequentially switches the light emission mode of the plurality of LED elements according to the lighting pattern.

[0011] Preferably, the inspection lighting system stores the lighting pattern in a rewritable format. This allows the width, shape, and transition speed of the patterned light to be freely changed according to the application.

[0012] In the aforementioned inspection lighting system, it is preferable that the LED substrate is square-shaped. This allows for a greater variety of shapes for the light-emitting surface formed by combining LED modules compared to the case where the LED substrate is rectangular.

[0013] The inspection lighting system preferably includes an LED module equipped with a control board that controls the light-emitting mode of the plurality of LED elements, and the LED board and the control board are connected using a flexible board or the like. This reduces the space at the edges of the LED board, so that when multiple LED boards are lined up, the LED elements can be arranged at equal pitches between adjacent LED boards, while also increasing the mounting density when considering each LED board individually.

[0014] Furthermore, a specific embodiment of the inspection illumination system is one in which the predetermined pattern is a striped pattern, and the light of the striped pattern is irradiated onto the surface of the workpiece while transitioning its phase. Such a system can be suitably used in a surface analysis system that utilizes the so-called phase shift method, which analyzes the surface shape of a workpiece based on multiple captured images obtained by projecting light of striped patterns with different phases onto the surface of the workpiece to be analyzed.

[0015] Preferably, the inspection lighting system is configured to allow switching between the vertical and horizontal directions of the alignment of the striped pattern of light and the direction of its transition. With such a configuration, more complex switching control is possible, and the effects of the present invention described above become more pronounced.

[0016] According to the present invention configured in this way, in an inspection lighting system that irradiates a workpiece while transitioning between predetermined patterns of light, it is possible to suppress response delays due to data transmission while increasing the degree of freedom in customizing the size of the light-emitting surface.

[0017] A schematic diagram showing the overall configuration of an inspection system according to one embodiment of the present invention. A schematic perspective view showing the overall configuration of an inspection illuminator according to the same embodiment. A schematic perspective view showing the overall configuration of an LED module according to the same embodiment. A schematic diagram showing the configuration of the drive circuit for the LED module according to the same embodiment. A schematic diagram showing the overall configuration of an inspection lighting system according to the same embodiment. A diagram showing the time change of the striped pattern on the light-emitting surface of the inspection lighting system according to the same embodiment. A diagram showing a custom example of the light-emitting surface of the inspection lighting system according to the same embodiment. A diagram showing an example of the light-emitting pattern on the light-emitting surface of an inspection lighting system according to another embodiment.

[0018] Hereinafter, an inspection lighting system 400 according to one embodiment of the present invention will be described with reference to the drawings.

[0019] The inspection lighting system 400 of this embodiment is used in a surface shape analysis system that analyzes the uneven surface shape of a workpiece W using, for example, a phase shift method. It irradiates the surface of the workpiece W with light in a striped pattern and shifts the phase of this striped pattern. The inspection lighting system 400 of this embodiment is configured to allow switching between the direction in which the light of the irradiated striped pattern is aligned and the direction of its transition, both vertically and horizontally, and is referred to as a so-called two-axis phase shift illumination.

[0020] Specifically, as shown in Figure 1, this inspection lighting system 400 comprises an inspection illuminator 100, a power supply device 200 that supplies power to the inspection illuminator 100, and a controller 300 that controls the light emission mode of the inspection illuminator 100.

[0021] The inspection illuminator 100 has a light-emitting surface S capable of emitting light in a striped pattern. As shown in Figure 2, the light-emitting surface S is formed by a plurality of LED elements 11 arranged in a vertical and horizontal matrix. The light-emitting surface S in this embodiment is square in shape. Each LED element 11 emits light of any color, such as white light, and is arranged at equal pitches.

[0022] The power supply unit 200 inputs a DC voltage to the drive circuit C of the inspection illuminator 100, and specifically is a CVCC power supply or the like.

[0023] The controller 300 functions as a trigger output unit T that outputs a trigger signal to the inspection illuminator 100 that commands the switching of the phase of the striped pattern on the light-emitting surface S. In this embodiment, each time a trigger signal is output, the phase of the striped pattern on the light-emitting surface S is sequentially switched.

[0024] However, in the inspection lighting system 400 of this embodiment, the inspection illuminator 100 is composed of a plurality of LED modules LM arranged in a row. Each LED module LM has one LED substrate 1 on which a plurality of LED elements 11 are mounted, and by being arranged in a row, the plurality of LED substrates 1 form one light-emitting surface S of the inspection illuminator 100. In this embodiment, one inspection illuminator 100 is composed of a total of nine LED modules LM arranged in a 3x3 grid. Note that the combination of LED modules LM is not limited to this, and they may be arranged in any number of rows and columns.

[0025] Each of the multiple LED modules LM individually stores a lighting pattern that shows the transition of the light-emitting modes of the multiple LED elements 11. When it receives a trigger signal output from the trigger output unit T, the light-emitting modes of the multiple LED elements 11 are switched according to the stored lighting pattern. In this embodiment, each LED module LM sequentially switches the light-emitting modes of the multiple LED elements 11 each time it receives a trigger signal. The light-emitting modes of the multiple LED modules LM are switched simultaneously. The structure of the LED module LM will be described below.

[0026] As shown in Figures 2 and 3, the multiple LED modules LM all have the same structure and include the aforementioned LED substrate 1 and a control substrate 2 that controls the light emission mode of the LED elements 11. The control substrate 2 is located on the back side of the LED substrate 1. In this embodiment, the LED substrate 1 and the control substrate 2 are integrated using a flexible substrate 5, but this is not limited to this configuration.

[0027] The LED substrate 1 has a rectangular shape (specifically, a square shape) when viewed from above. LED elements 11 are mounted on the LED substrate 1 so that there are the same number of rows vertically and horizontally (in this case, 13 vertically x 13 horizontally). In addition, multiple resistor elements 12 are mounted on the LED substrate 1, connected in series with each LED element 11.

[0028] The control board 2 is equipped with multiple switching elements SW that open and close the circuits to which each LED element 11 is connected, a memory unit 21, a switch control unit 22, and a communication unit 23. The switching elements SW are, for example, field-effect transistors such as MOSFETs, but are not limited to these.

[0029] Here, we will describe an example of the circuit configuration of the LED module LM. As shown in Figure 4, in this drive circuit C, multiple wires are arranged so as to intersect vertically and horizontally. The points where these vertically and horizontally arranged wires intersect each other are insulated. An LED element 11 and a resistor element 12 are connected in series at each intersection point of the horizontal wires Y1 to Yn and the vertical wires X1 to Xn. More specifically, one side of the LED element 11, the anode side or the cathode side, is connected to the horizontal wires Y1 to Yn, and the other side is connected to the vertical wires X1 to Xn. A switching element SW is connected to the end of each vertical wire X1 to Xn and each horizontal wire Y1 to Yn.

[0030] In such a drive circuit C, for example, by inputting a signal to the switching elements SW connected to the horizontal wires and turning them all on, and by turning on the switching elements SW connected to the vertical wires, for example, every other one, a striped pattern is formed in which the LED elements 11 light up in alternating rows along the horizontal direction. Then, for example, by switching the switching elements SW connected to the vertical wires on and off alternately, the striped pattern can be moved horizontally. Furthermore, by switching the switching elements SW on and off in the vertical and horizontal directions, it is possible to light up a striped pattern along the horizontal direction and move it vertically. Moreover, with this drive circuit C, by changing the on / off pattern of the switching elements SW, multiple LED elements 11 can be made to light up at any width and spacing, and the light-emitting area can be moved by any number of rows.

[0031] The memory unit 21 pre-stores lighting patterns that represent the transitions in the light emission modes of multiple LED elements 11, consisting of multiple stages. These lighting patterns also represent the transitions in the on / off patterns of multiple switching elements SW. These lighting patterns can be rewritten using the controller 300.

[0032] In this embodiment, the lighting patterns stored in the memory unit 21 of each LED module LM are individually set so that the light-emitting surface S, which consists of multiple LED substrates 1, forms a single striped pattern as a whole, and the phase of the striped pattern transitions. In this way, the striped pattern is formed across the multiple LED substrates 1 and moves across the multiple LED substrates 1.

[0033] The switch control unit 22 receives a trigger signal output from the trigger output unit T and, according to the lighting pattern stored in the memory unit 21, inputs a signal to the switching element SW to switch it on or off. Each time the switch control unit 22 receives a trigger signal, it switches the on / off pattern of the switching element SW one step at a time according to the lighting pattern.

[0034] The communication unit 23 enables data communication with the controller 300 using a communication standard such as Ethernet. By operating the controller 300, the user can rewrite the lighting pattern stored in the memory unit 21 via the communication unit 23.

[0035] In addition, in the LED module LM of this embodiment, a heat sink 3 is installed between the LED board 1 and the control board 2, and the LED board 1 and the control board 2 are each in contact with the heat sink 3. Furthermore, a fan 4 is provided on the back side of the control board 2.

[0036] As shown in Figure 5, the control boards 2 of each LED module LM are connected serially to the controller 300. The trigger signal output from the controller 300 is configured to be transmitted sequentially between the multiple control boards 2 via trigger lines.

[0037] Each control board 2 is also equipped with a DC / DC converter (not shown) that reduces the DC voltage (48V in this case) supplied from the power supply unit 200 to a predetermined DC voltage (3.6V in this case). The DC voltage supplied from the power supply unit 200 is reduced in voltage by the DC / DC converter before being applied to the drive circuit C.

[0038] Figure 6 shows an example of the phase transition of the striped pattern of the inspection illuminator 100 of this embodiment. The striped pattern of this embodiment is a vertical stripe pattern in which light-emitting regions R1, where the LED elements 11 are emitting light, and off-light regions R2, where the LED elements 11 are not lit, are alternately repeated along the horizontal direction. Specifically, this striped pattern consists of light-emitting regions R1 made up of multiple rows (6 rows in this case) of emitting LED elements 11, and off-light regions R2 made up of multiple rows (6 rows in this case) of off-light LED elements 11, which are alternately repeated along the horizontal direction. Each time a trigger signal is output from the trigger output unit T, the light-emitting regions R1 and off-light regions R2 move by multiple rows (3 rows in this case) along the horizontal direction.

[0039] In this configuration of the inspection lighting system 400, a single light-emitting surface S is formed by arranging multiple LED modules LM side by side. Therefore, the size of the light-emitting surface S can be freely changed by changing the number and arrangement of the LED modules LM. Furthermore, each of the multiple LED modules LM individually stores the lighting pattern of the LED element 11, and the controller 300 can transition the phase of the striped pattern simply by outputting a trigger signal to each LED module LM. For this reason, compared to storing the lighting pattern in the controller 300 and transmitting control signals to control the light emission mode of the LED element 11 from the controller 300 to each LED module LM, the response speed can be significantly faster, and there is no need to transfer lighting data each time the pattern phase is transitioned. For this reason, even if the number of LED modules increases, the transition of the striped pattern phase in response to the trigger can be achieved with high responsiveness.

[0040] It should be noted that the present invention is not limited to the above-described embodiments. For example, in the above-described embodiment, the inspection illuminator 100 had a plurality of LED modules LM arranged so that the light-emitting surface S was square in shape, but the invention is not limited to this. In other embodiments of the inspection illuminator 100, the plurality of LED modules LM may be arranged so that the light-emitting surface S is rectangular in shape. For example, as shown in Figure 7(a), the LED modules LM may be arranged in a 2x4 grid, or as shown in Figure 7(b), the LED modules LM may be arranged in a 1x9 grid.

[0041] Furthermore, while the LED module LM of the above embodiment comprises one LED substrate 1 and one control substrate 2, it is not limited to this configuration. The LED module LM of other embodiments may comprise multiple LED substrates 1 and one control substrate 2.

[0042] In other embodiments of the inspection illuminator 100, the phase of the striped pattern is sequentially switched each time a trigger signal is output, but this is not limited to this. In other embodiments, after a trigger signal is output once, the phase of the striped pattern may be sequentially switched at a certain timing based on, for example, a clock signal.

[0043] Furthermore, while the inspection illuminator 100 is configured such that each LED module LM emits light from the light-emitting surface S in a vertical stripe pattern and transitions its phase, it is not limited to this configuration. In other embodiments of the inspection illuminator 100, each LED module LM may be configured to emit light from the light-emitting surface S in any pattern other than the vertical stripe pattern and transition its phase. For example, as shown in Figure 8, the light-emitting surface S may emit light in a ring-shaped stripe pattern and transition its phase. Alternatively, as shown in Figure 9, the light-emitting surface S may emit light in a grid pattern and transition its phase. Furthermore, the light-emitting surface S may emit light in a diagonal stripe pattern and transition its phase.

[0044] Furthermore, while the LED module LM in the above embodiment had a square-shaped LED substrate 1, it is not limited to this. The LED module LM in other embodiments may have a rectangular-shaped LED substrate 1.

[0045] Also, in another embodiment, in the LED module LM, the LED substrate 1 and the control substrate 2 may be connected using, for example, an inter-board connector or the like. Further, the power supply device 200 and the controller 300 may be provided integrally.

[0046] Also, the LED substrate 1 included in each LED module LM may be, for example, an LED panel for video display or an LED panel used for a backlight of a liquid crystal.

[0047] Needless to say, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit thereof.

[0048] In an inspection illumination system that irradiates a workpiece while transitioning light of a predetermined pattern, the degree of freedom in customizing the light emitting surface size and the light emitting pattern is increased while suppressing the response delay due to data transmission.

[0049] 400... Inspection illumination system S... Light emitting surface LM... LED module 1... LED substrate 11... LED element 2... Control substrate T... Trigger output unit W... Workpiece

Claims

1. An inspection lighting system having a light-emitting surface that emits light in a predetermined pattern, and irradiating the surface of a workpiece while transitioning the light of the predetermined pattern, comprising: a plurality of LED modules having an LED substrate on which a plurality of LED elements are mounted, and which are arranged in a row to form a single light-emitting surface; and a trigger output unit that outputs a trigger signal to the plurality of LED modules to command the transition of the predetermined pattern, wherein each of the plurality of LED modules individually stores a lighting pattern indicating the transition of the light-emitting mode of the plurality of LED elements, and when it receives the trigger signal, it switches the light-emitting mode of the plurality of LED elements according to the lighting pattern.

2. The inspection lighting system according to claim 1, wherein each of the plurality of LED modules sequentially switches the light emission mode of the plurality of LED elements in accordance with the lighting pattern each time it receives the trigger signal.

3. The inspection lighting system according to claim 1, wherein the lighting pattern is stored in a rewritable manner.

4. The inspection lighting system according to claim 1, wherein the LED substrate is square in shape.

5. The inspection lighting system according to claim 1, wherein the LED module includes a control board for controlling the light emission modes of the plurality of LED elements, and the LED board and the control board are connected using a flexible board.

6. The inspection lighting system according to any one of claims 1 to 5, wherein the predetermined pattern is a striped pattern, and the light of the striped pattern is irradiated onto the surface of the workpiece while transitioning its phase.

7. The inspection lighting system according to claim 6, configured to allow switching between the vertical and horizontal directions of the alignment of the striped pattern of light and the direction of transition between them.

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