JP6847088B2 - Projection device and 3D measuring device - Google Patents

Description

The present invention relates to a projection device that projects a predetermined pattern light and a three-dimensional measurement device including the projection device that projects a predetermined pattern light when performing three-dimensional measurement using a pattern projection method such as a phase shift method.

Generally, when an electronic component is mounted on a printed circuit board, cream solder is first printed on a predetermined electrode pattern arranged on the printed circuit board. Next, the electronic component is temporarily fixed on the printed circuit board based on the viscosity of the cream solder. After that, the printed circuit board is guided to the reflow furnace, and soldering is performed by passing through a predetermined reflow step. Nowadays, it is necessary to inspect the printing state of cream solder before being guided to the reflow furnace, and a three-dimensional measuring device may be used for such inspection.

Conventionally, various three-dimensional measuring devices have been proposed that project a predetermined pattern light to perform three-dimensional measurement. Among them, a three-dimensional measuring device using a phase shift method is well known.

A three-dimensional measuring device using the phase shift method is a projection device that projects patterned light having a striped light intensity distribution (hereinafter referred to as "striped pattern") onto an object to be measured such as a printed circuit board from diagonally above. , It is provided with an imaging device that images an object to be measured on which the striped pattern is projected.

The projection device includes a light source that emits a predetermined light and a pattern generation unit that converts the light from the light source into a fringe pattern, and the fringe pattern generated here is covered via a projection optical system including a projection lens or the like. Projected onto the object to be measured.

Under such a configuration, the phase of the fringe pattern projected on the object to be measured is shifted in a plurality of ways (for example, 4 ways), and imaging is performed under each fringe pattern having a different phase. Get image data. Then, three-dimensional measurement of the object to be measured is performed based on these image data.

However, some of the measurement targets whose height is actually measured have a high height and some have a low height. For example, with regard to cream solder, the height of cream solder printed on a conventional general printed circuit board is usually about 100 μm, but in recent years, the height of in-vehicle printed circuit boards has been increasing with the electrification of automobiles. Since a power circuit or the like is mounted on the surface, the height of the cream solder may be about 300 to 400 μm.

Here, for example, if a three-dimensional measuring device in which the period of the stripe pattern to be projected is longer than the conventional one is used according to the printed circuit board for vehicles, the dynamic range of the height is increased and the printed circuit board for vehicles can be measured. However, when this is used for the measurement of a conventional general printed circuit board, the height resolution becomes coarse and the measurement accuracy may deteriorate.

Therefore, in order to make the three-dimensional measuring device versatile, a fringe pattern having a long cycle is projected when the degree of unevenness of the object to be measured such as a printed circuit board is large, and a short cycle is projected when the degree of unevenness is small. It is necessary to project a fringe pattern according to the degree of unevenness of the object to be measured, such as projecting a fringe pattern.

However, when a conventional grid plate in which a grid pattern is printed on a film or glass plate is used as the pattern generator, the width and pitch of the printed grid pattern cannot be changed, so that the pattern is projected onto the object to be measured. The stripe pattern is constant.

Therefore, if it is attempted to project different fringe patterns according to the degree of unevenness of the object to be measured by a three-dimensional measuring device using a grid plate, a plurality of grid plates having different widths and pitches of the printed grid patterns are prepared in advance. It is necessary to prepare and use these lattice plates properly according to the degree of unevenness of the object to be measured. As described above, the three-dimensional measuring device in which the lattice plate must be replaced each time is inconvenient and may cause a decrease in productivity.

On the other hand, as a pattern generation unit, a three-dimensional measuring device or the like using a liquid crystal element or the like in which a plurality of pixels are two-dimensionally arranged in a matrix can be seen.

However, in the conventional liquid crystal element, since the space between pixels is a dark part, the generated fringe pattern is microscopically discontinuous, so that the fringe pattern projected on the object to be measured is assumed. The fringe pattern does not appear, and the measurement accuracy of the three-dimensional measurement may decrease.

On the other hand, in recent years, in order to solve the above-mentioned problems, a special liquid crystal element is used to change the width and pitch of the lattice pattern according to the degree of unevenness of the object to be measured, so that a fringe pattern having a different period can be projected. Three-dimensional measuring devices are also found (see, for example, Patent Document 1).

Specifically, in the three-dimensional measuring device described in Patent Document 1, N strip-shaped electrodes having a constant pitch and width are formed on the liquid crystal element, and the strike is performed with the number of electrodes n which is a multiple of 3 or 4. The live electrodes are divided into N / n groups, one lattice having a sine wave-shaped intensity distribution is created for each group, and one cycle of the sine wave is set to n or the like according to the number of electrodes n. Divided into minutes, a liquid crystal drive signal corresponding to the sum of the amplitude of the sine wave in each of the divided regions and the bias intensity of the sine wave is applied to each of the stripe electrodes to obtain the sine wave intensity. N / n lattice patterns (striped patterns) having a distribution are generated, and one cycle of the lattice pattern is divided into 3 or 4 as a unit, and the voltage of the liquid crystal drive signal applied to the stripe electrode is applied. The arrangement of the above is sequentially changed, the phase of the lattice pattern is shifted by 2π / 3 or π / 2 pitch, and the number of electrodes n is changed to form a lattice pattern suitable for the surface shape of the object to be measured. It is configured as follows.

Japanese Unexamined Patent Publication No. 11-83454

However, the configuration according to Patent Document 1 requires the above-mentioned special liquid crystal element, which may increase the manufacturing cost of the projection device.

Further, since the liquid crystal element passes through the polarizing filter, the fringe pattern projected on the object to be measured may be darkened. As a result, it is not possible to acquire accurate luminance image data, and the measurement accuracy of the three-dimensional measurement may decrease.

It should be noted that the above-mentioned problem is not necessarily limited to three-dimensional measurement of cream solder or the like printed on a printed circuit board, but is inherent in other fields of three-dimensional measurement. Of course, the problem is not limited to the phase shift method.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a projection device and a three-dimensional measurement device capable of improving measurement accuracy in performing three-dimensional measurement using a pattern projection method. To do.

Hereinafter, each means suitable for solving the above problems will be described separately for each item. In addition, the action and effect peculiar to the corresponding means will be added as necessary.

Means 1. A projection device that projects a predetermined pattern of light onto a predetermined object to be measured when performing three-dimensional measurement on the object to be measured (for example, a printed circuit board).
A light source that emits a predetermined amount of light,
A pattern generator that converts light incident from the light source into pattern light and emits it.
It is provided with a projection optical system that forms an image of pattern light emitted from the pattern generation unit on the object to be measured.
The pattern generator
A plurality of lattice members having a lattice pattern in which a translucent portion that transmits light at a predetermined transmittance and a light-shielding portion that blocks at least a part of light are alternately arranged in a first direction (for example, a horizontal direction) are the first. It is arranged so as to face each other in the second direction (for example, the vertical direction) orthogonal to the one direction, and
By providing a lattice moving means capable of changing the relative positional relationship of the plurality of lattice members with respect to the first direction.
A projection device characterized in that the period of pattern light projected on the object to be measured can be changed.

The "lattice member" includes a material in which a lattice pattern is printed (deposited) on a base material formed in a flat plate shape or a film shape by a translucent material such as glass or acrylic resin, or an opaque resin or metal. Etc. are included in which a lattice pattern is formed by forming an opening such as a slit by processing the above.

According to the above means 1, by forming a pattern generation unit that converts light from a light source into pattern light by using a plurality of lattice members, it is possible to project brighter pattern light than when a liquid crystal lattice or the like is used. Become.

Further, by providing the grid moving means for changing the relative positional relationship of the plurality of grid members, it is possible to change the period (pitch) of the pattern light projected on the object to be measured without exchanging the grid members. ..

Further, since an inexpensive optical member such as an existing lattice plate in which a lattice pattern is printed on a base material such as a glass plate can be used, when an expensive optical control element such as a liquid crystal element is used as a pattern generator. Compared with the above, the manufacturing cost of the pattern generation unit can be suppressed.

In addition, unlike the case of using an existing liquid crystal element or the like, it is not necessary to control the pixels, the control can be simplified, and the generated pattern light becomes microscopically discontinuous. Therefore, it is possible to project a more ideal pattern light onto the object to be measured.

Means 2. The projection device according to means 1, wherein the lattice patterns formed on the plurality of lattice members are the same.

According to the above means 2, by using a plurality of lattice members having the same lattice pattern, it is possible to simplify the configuration of the pattern generation unit, simplify the movement control of the lattice members, suppress the increase in manufacturing cost, and the like. it can.

Here, the above-mentioned "same lattice pattern" means that the width of the light-transmitting portion in the first direction is the same, the width of the light-shielding portion in the first direction is the same, and the width of the light-shielding portion is the same. It means that the ratio of the light-transmitting portion and the light-shielding portion in the above is the same, and that the formation pitches of the light-transmitting portion and the light-shielding portion in the first direction are the same.

The ratio of the light-transmitting portion to the light-shielding portion in the composite lattice pattern in which the lattice patterns of a plurality of lattice members are superimposed is preferably completely the same, but may be substantially the same. If they are substantially the same, it is possible to generate pattern light with sufficient accuracy for performing three-dimensional measurement using the pattern projection method.

Means 3. The pattern generator
The light-shielding portion of the lattice pattern in one of the two lattice members facing each other in the second direction and the light-shielding portion of the lattice pattern in the other lattice member are connected in the first direction. By arranging the two lattice members, a long-period pattern light can be generated.
By arranging the two lattice members so that the light-shielding portion of the lattice pattern in the one lattice member and the light-shielding portion of the lattice pattern in the other lattice member are separated from each other in the first direction, the two lattice members are shortened. The projection device according to means 1 or 2, characterized in that it is configured to be capable of generating periodic pattern light.

According to the above means 3, a long-period pattern light in which a dark portion of the pattern light generated by the light-shielding portion of one lattice member and a dark portion of the pattern light generated by the light-shielding portion of the other lattice member are connected, and Switching between two types of pattern light, a dark part of the pattern light generated by the light-shielding part of one grid member and a short-period pattern light in which the dark part of the pattern light generated by the light-shielding part of the other grid member is separated. Can be projected.

Means 4. The pattern generator
The position of the end of the light-shielding portion of the lattice pattern on one of the lattice members on the one end side in the first direction and the position of the end of the light-shielding portion of the lattice pattern on the other lattice member on the other end of the first direction are first. The projection device according to means 3, wherein the two lattice members are arranged so as to be in the same position in the same direction so that the long-period pattern light can be generated.

According to the above means 4, the ratio of the bright part and the dark part can be made the same for both the long-period pattern light and the short-period pattern light. As a result, more ideal pattern light can be projected onto the object to be measured.

Means 5. The pattern generator
The predetermined range including the one end portion of the light-shielding portion of the lattice pattern in the one lattice member in the first direction and the predetermined range including the other end portion of the light-shielding portion of the lattice pattern in the other lattice member in the first direction are described above. The projection device according to means 3, wherein the two lattice members are arranged so as to overlap each other in the first direction so that the long-period pattern light can be generated.

According to the above means 5, it is possible to reduce the leakage of light between the two light-shielding portions by overlapping a part of the light-shielding portions of the two opposing lattice members. As a result, more ideal pattern light can be projected onto the object to be measured.

Means 6. Any of means 1 to 5, wherein the plurality of lattice members are composed of one fixed lattice member and at least one movable lattice member provided so as to be relatively displaceable with respect to the fixed lattice member. The projection device described in the grid.

According to the above means 6, the movement control of the grid member can be simplified, and the projection position (projection reference position) of the pattern light can be stabilized by the presence of the fixed grid member.

Means 7. The projection device according to any one of means 1 to 6, wherein the light-shielding portion is composed of a plurality of portions having different transmittances.

According to the means 7, the transmittance is medium between a portion having a high transmittance (for example, a translucent portion) and a portion having a low transmittance (for example, a portion having a lower transmittance in the light-shielding portion). A portion can be provided, and a more ideal pattern light can be projected onto the object to be measured.

Means 8. The projection device according to any one of means 1 to 7, wherein as the pattern light, a pattern light having a striped (for example, sinusoidal) light intensity distribution can be projected.

According to the above means 8, three-dimensional measurement by the phase shift method can be performed by projecting pattern light having a striped light intensity distribution. As a result, it is possible to improve the measurement accuracy of the three-dimensional measurement.

In a configuration such as the phase shift method in which three-dimensional measurement is performed based on the difference in the brightness values of a plurality of image data captured and acquired under different phase pattern light, even if the error in the brightness values is small. , May have a great impact on measurement accuracy. Therefore, under the configuration related to this means, the action and effect of each of the above means will be more effective. In particular, pattern light having a sinusoidal light intensity distribution requires high projection accuracy because the light intensity distribution (waveform) tends to collapse.

Means 9. The projection device according to any one of means 1 to 8 and
An imaging means capable of capturing a predetermined range of the object to be measured on which the pattern light is projected, and an imaging means.
A three-dimensional measuring device provided with an image processing means capable of performing three-dimensional measurement relating to the object to be measured based on the image data captured and acquired by the imaging means.

According to the means 9, the three-dimensional measurement can be performed by using the pattern light projected from the projection device according to any one of the means 1 to 8. Normally, when performing three-dimensional measurement using the pattern projection method, the light emitted from a predetermined light source is converted into a predetermined pattern light by the pattern generation unit and projected onto the object to be measured via the projection optical system. To do. Then, the object to be measured on which the pattern light is projected is imaged by the imaging means, and the three-dimensional measurement of the object to be measured is performed based on the acquired image data.

More specifically, as a three-dimensional measuring device that performs three-dimensional measurement by the phase shift method using the pattern light projected from the projection device according to the above means 8.
"The projection device according to means 8 and
An imaging means capable of capturing a predetermined range of the object to be measured on which the pattern light is projected, and an imaging means.
A pattern light displacement means that changes the relative positional relationship (phase) between the pattern light projected by the projection device and the object to be measured.
The object to be measured is related to the object to be measured by a phase shift method based on a plurality of image data of the object to be measured acquired by being imaged by the imaging means in a state where the relative positional relationship between the pattern light and the object to be measured is different. A three-dimensional measuring device characterized by being provided with an image processing means capable of performing three-dimensional measurement. Is given as an example.

Examples of the "object to be measured" include a printed circuit board on which cream solder is printed. That is, by using the projection device described in each of the above means, it is possible to perform three-dimensional measurement of the cream solder printed on the printed circuit board. As a result, in the cream solder inspection, the quality of the cream solder can be determined based on the measured value. Therefore, in such an inspection, the action and effect of each of the above means are exhibited, and the quality judgment can be performed with high accuracy. As a result, the inspection accuracy of the solder printing inspection apparatus can be improved.

It is a schematic diagram which shows the schematic structure of the substrate inspection apparatus. It is a plane schematic diagram which shows the schematic structure of the printed circuit board. It is sectional drawing of the printed circuit board. It is a schematic diagram which shows the mode of the stripe pattern projected on the printed circuit board. It is a schematic diagram which shows the schematic structure of the projection apparatus. It is a block diagram which shows the electrical structure of a substrate inspection apparatus. It is a schematic diagram which shows the schematic structure of the lattice unit. It is a figure for demonstrating the change of the relative positional relationship of a fixed lattice plate and a movable lattice plate, and (a) is a schematic of the relative positional relationship of a fixed lattice plate and a movable lattice plate at the time of projecting a long-period stripe pattern. FIG. 3B is a perspective view schematically showing the relative positional relationship between the fixed grid plate and the movable grid plate when projecting a short-period fringe pattern. It is a figure for demonstrating the change of the relative positional relationship of a fixed lattice plate and a movable lattice plate, and (a) shows the relative positional relationship of a fixed lattice plate and a movable lattice plate at the time of projecting a long-period stripe pattern. It is a schematic diagram, and (b) is a schematic diagram showing the relative positional relationship between the fixed grid plate and the movable grid plate when projecting a short-period fringe pattern. It is a figure for demonstrating the change of the relative positional relationship of the fixed lattice plate and the movable lattice plate in 2nd Embodiment, and (a) is the figure of the fixed lattice plate and the movable lattice plate at the time of projecting a long-period fringe pattern. It is a schematic diagram which shows the relative positional relationship, and (b) is a schematic diagram which shows the relative positional relationship of a fixed lattice plate and a movable lattice plate at the time of projecting a short-period stripe pattern. It is a figure for demonstrating the change of the relative positional relationship of the fixed lattice plate and the movable lattice plate in 3rd Embodiment, and (a) is the figure of the fixed lattice plate and the movable lattice plate at the time of projecting a long-period fringe pattern. It is a schematic diagram which shows the relative positional relationship, and (b) is a schematic diagram which shows the relative positional relationship of a fixed lattice plate and a movable lattice plate at the time of projecting a short-period stripe pattern. It is a figure for demonstrating the change of the relative positional relationship of the fixed lattice plate and the movable lattice plate in 4th Embodiment, and (a) is the figure of the fixed lattice plate and the movable lattice plate at the time of projecting a long-period fringe pattern. It is a schematic diagram which shows the relative positional relationship, and (b) is a schematic diagram which shows the relative positional relationship of a fixed lattice plate and a movable lattice plate at the time of projecting a short-period stripe pattern. It is a figure for demonstrating the change of the relative positional relationship of the fixed lattice plate and the movable lattice plate in 5th Embodiment, and (a) is the figure of the fixed lattice plate and the movable lattice plate at the time of projecting a long-period fringe pattern. It is a schematic diagram which shows the relative positional relationship, and (b) is a schematic diagram which shows the relative positional relationship of a fixed lattice plate and a movable lattice plate at the time of projecting a short-period stripe pattern. It is a figure for demonstrating the change of the relative positional relationship of the fixed lattice plate and the movable lattice plate in 6th Embodiment, and (a) is the figure of the fixed lattice plate and the movable lattice plate at the time of projecting a long-period fringe pattern. It is a schematic diagram which shows the relative positional relationship, and (b) is a schematic diagram which shows the relative positional relationship of a fixed lattice plate and a movable lattice plate at the time of projecting a short-period stripe pattern.

[First Embodiment]
Hereinafter, one embodiment will be described with reference to the drawings. First, the configuration of the printed circuit board 1 to be the object to be measured in the present embodiment will be described in detail (see FIGS. 2 and 3). FIG. 2 is a schematic plan view showing a schematic configuration of the printed circuit board 1. FIG. 3 is a schematic cross-sectional view of the printed circuit board 1.

As shown in FIGS. 2 and 3, the printed circuit board 1 has an electrode pattern 3A and a land 3B made of copper foil formed on the surface of a flat plate-shaped base substrate 2 made of glass epoxy resin or the like. A resist film 4 is coated on the surface of the base substrate 2 except for the land 3B and its vicinity. Then, the cream solder 5 is printed on the land 3B.

The printed circuit board 1 according to the present embodiment is an in-vehicle printed circuit board mounted on, for example, an electric vehicle, and includes a power circuit unit PA on which electronic components such as an inverter circuit through which a relatively large load current flows are mounted. A control circuit unit PB on which electronic components through which a relatively small signal current flows, such as a control circuit for controlling the control circuit, is mixed.

Next, the substrate inspection device 10 constituting the three-dimensional measuring device in the present embodiment will be described in detail (see FIG. 1). FIG. 1 is a schematic view showing a schematic configuration of a substrate inspection device 10. Hereinafter, the left-right direction of the paper surface in FIG. 1 will be referred to as the “X-axis direction”, the front-back direction of the paper surface will be referred to as the “Y-axis direction”, and the vertical direction (vertical direction) of the paper surface will be referred to as the “Z-axis direction”.

The substrate inspection device 10 is a solder printing inspection device that inspects the printing state of the cream solder 5 printed on the printed circuit board 1. The substrate inspection device 10 includes a transport mechanism 11 for transporting and positioning the printed circuit board 1, an inspection unit 12 for inspecting the printed circuit board 1, and a substrate inspection device 10 for driving control of the transport mechanism 11 and the inspection unit 12. It is provided with a control device 13 (see FIG. 6) for performing various controls, image processing, and arithmetic processing in the room.

The transfer mechanism 11 includes a pair of transfer rails 11a arranged along the transfer direction (Y-axis direction) of the printed substrate 1, an endless conveyor belt 11b rotatably arranged with respect to each transfer rail 11a, and the same. It is provided with a driving means (not shown) such as a motor for driving the conveyor belt 11b and a chuck mechanism (not shown) for positioning the printed substrate 1 at a predetermined position, and is driven and controlled by the control device 13.

Under the above configuration, the printed circuit board 1 carried into the substrate inspection device 10 has both side edges in the width direction (X-axis direction) orthogonal to the transport direction inserted into the transport rail 11a and on the conveyor belt 11b. It will be placed. Subsequently, the conveyor belt 11b starts operation, and the printed circuit board 1 is conveyed to a predetermined inspection position. When the printed circuit board 1 reaches the inspection position, the conveyor belt 11b stops and the chuck mechanism operates. By the operation of this chuck mechanism, the conveyor belt 11b is pushed up, and both side edges of the printed circuit board 1 are sandwiched between the conveyor belt 11b and the upper side of the transport rail 11a. As a result, the printed circuit board 1 is positioned and fixed at the inspection position. When the inspection is completed, the fixing by the chuck mechanism is released and the conveyor belt 11b starts operation. As a result, the printed circuit board 1 is carried out from the substrate inspection device 10. Of course, the configuration of the transport mechanism 11 is not limited to the above-mentioned form, and other configurations may be adopted.

The inspection unit 12 is arranged above the transport path (pair of transport rails 11a) of the printed circuit board 1. The inspection unit 12 includes a projection device 14 that projects a striped pattern W (see FIG. 4) from diagonally above a predetermined inspection range on the printed circuit board 1, and a predetermined inspection unit 12 on the printed circuit board 1 on which the striped pattern W is projected. A camera 15 as an imaging means that captures an inspection range from directly above, an X-axis moving mechanism 16 (see FIG. 6) that enables movement in the X-axis direction, and a Y-axis that enables movement in the Y-axis direction. It is provided with a moving mechanism 17 (see FIG. 6) and is driven and controlled by a control device 13.

As shown in FIG. 2, the predetermined inspection range on the printed circuit board 1 is a plurality of areas (predetermined) set on the printed circuit board 1 with the size of the imaging field of view (imaging range) K of the camera 15 as one unit. It is one of the inspection ranges "1" to "15").

The control device 13 drives and controls the X-axis moving mechanism 16 and the Y-axis moving mechanism 17, so that the inspection unit 12 (imaging field of view K) is positioned and fixed at the inspection position in an arbitrary inspection range on the printed circuit board 1. It can be moved to the upper position. Then, while sequentially moving the inspection unit 12 to a plurality of inspection ranges set on the printed circuit board 1, the inspection process related to each inspection range is executed, so that the solder printing inspection related to the entire printed circuit board 1 is executed. It is configured to do.

As shown in FIG. 5, the projection device 14 is generated by a light source 19 that emits predetermined light, a grid unit 20 as a pattern generation unit that converts light from the light source 19 into a fringe pattern W, and the grid unit 20. A grid for changing the phase of the striped pattern W projected on the printed substrate 1 by displaced the projection lens unit 21 as a projection optical system that forms an image of the striped pattern W on the printed substrate 1 and the grid unit 20. It is provided with a unit moving mechanism 22 (see FIG. 7) and is driven and controlled by a control device 13.

The projection device 14 is arranged so that its optical axis J1 is parallel to the XZ plane and is inclined by a predetermined angle α (for example, 30 °) with respect to the Z axis direction.

The light source 19 is composed of a halogen lamp that emits white light. The light emitted from the light source 19 is incident on the lattice unit 20 along the optical axis J1 in a state of being parallelized through a pretreatment lens group (not shown) or the like.

Here, the configuration of the lattice unit 20 will be described in detail with reference to FIG. 7. FIG. 7 is a schematic view showing a schematic configuration of the lattice unit 20.

When describing the lattice unit 20 alone, for convenience, the left-right direction of the paper surface in FIG. 7 is defined as the "X'axis direction", the front-back direction of the paper surface is defined as the "Y'axis direction", and the vertical direction of the paper surface is defined as the "Z'axis". It will be described as "direction".

However, the coordinate system (X', Y', Z') for explaining the lattice unit 20 alone and the coordinate system (X, Y, Z) for explaining the entire substrate inspection device 10 (projection device 14) are Different coordinate systems. Here, the "X'axis direction" corresponds to the "first direction" in the present embodiment, and the "Z'axis direction" corresponds to the "second direction".

As shown in FIG. 7, the lattice unit 20 includes a main body case portion 24 constituting the outer shell, a fixed lattice plate 25 as a fixed lattice member provided in the main body case portion 24, and a movable lattice member. A grid plate moving mechanism (pattern cycle changing mechanism) 27 for rearranging the grid plate 26 and the movable grid plate 26 with respect to the fixed grid plate 25 to change the cycle of the fringe pattern W projected on the printed circuit board 1. It has. The grid plate moving mechanism 27 constitutes the grid moving means in the present embodiment.

The main body case portion 24 has translucency, and the front surface thereof is the incident surface 20a of the lattice unit 20 that allows the light emitted from the light source 19 to enter the inside of the lattice unit 20, and the back surface thereof is the lattice unit 20. It is an exit surface 20b of the grid unit 20 that emits light (striped pattern W) transmitted through the inside.

The fixed grid plate 25 and the movable grid plate 26 are opposed to their own optical axis J3 (vertical direction in FIG. 7 which is the Z'axis direction) orthogonal to the incident surface 20a and the exit surface 20b of the lattice unit 20. It is arranged.

The fixed grid plate 25 is fixed to the main body case portion 24 so as not to be relatively displaceable. On the other hand, the movable grid plate 26 is provided so as to be displaceable along the X'axis direction (horizontal direction in FIG. 7) orthogonal to the optical axis J3.

The grid plate moving mechanism 27 is provided on one side (left side in FIG. 7) of the movable grid plate 26 in the X'axis direction, and serves as an urging means for urging the movable grid plate 26 toward the other side (right side in FIG. 7). A spring member 27a and a solenoid 27b provided on the other side of the movable lattice plate 26 in the X'axial direction and as a driving means for sliding and displacementing the movable lattice plate 26 along the X'axis direction are provided by the control device 13. Drive controlled.

On each of the lattice plates 25 and 26, a translucent portion 31 that transmits light at a predetermined transmittance and a light-shielding portion 32 that blocks at least a part of light are arranged so as to be alternately arranged in the X'axis direction. The grid pattern 30 is formed [see FIGS. 8 (a) and 8 (b)]. 8 (a) and 8 (b) are schematic views for explaining the change in the relative positional relationship between the fixed grid plate 25 and the movable grid plate 26.

Specifically, in each of the lattice plates 25 and 26 of the present embodiment, the light-shielding portion 32 is formed on a base material 28 formed in a flat plate shape or a film shape by a predetermined translucent material (for example, glass or acrylic resin). The lattice pattern 30 is formed by being printed (deposited) at predetermined intervals in the X'axis direction.

Then, in the present embodiment, the lattice plates 25 and 26 are arranged so that the printing surface (lattice surface) of the lattice pattern 30 faces the light source 19 side, that is, the incident side of the light [FIGS. 8 (a), 8 (a), b) See]. However, in FIG. 7, for the sake of clarity, not only the surface of each of the grid plates 25 and 26 but also the entire thickness direction of each of the grid plates 25 and 26 is blacked out for the portion corresponding to the light-shielding portion 32. (The same applies to FIGS. 9 to 14 described later).

Further, in the present embodiment, the lattice patterns 30 formed on the fixed lattice plate 25 and the movable lattice plate 26 are the same. That is, in both lattice plates 25 and 26, the width of the light transmitting portion 31 in the X'axis direction is the same, the width of the light shielding portion 32 in the X'axis direction is the same, and the width of the light transmitting portion 31 in the X'axis direction is the same. The ratio of the portions 32 is the same, and the formation pitches of the translucent portion 31 and the light-shielding portion 32 in the X'axis direction are the same.

Specifically, in the lattice plates 25 and 26 according to the present embodiment, the width of the light transmitting portion 31 in the X'axis direction is "600 (30 x 20) μm", and the width of the light shielding portion 32 in the X'axis direction is It is set to "200 (10 x 20) μm", and the ratio of the translucent portion 31 to the light-shielding portion 32 is "3: 1" [see FIGS. 9 (a) and 9 (b)]. The widths of the light-transmitting portion 31 and the light-shielding portion 32 in FIG. 9 are notated in a manner that is easy to compare with other embodiments shown in FIGS. 10 to 14 described later.

Under the above configuration, the grid unit 20 can switch the generated fringe pattern W to two types of fringe patterns W having different periods (strip pitch).

Specifically, in the present embodiment, there are two types of stripe patterns W: a first stripe pattern W1 having a first period of 800 μm (height resolution of 8 μm) and a second stripe pattern W2 having a second period of 400 μm (height resolution of 4 μm). Can be switched to. The "first cycle 800 μm" corresponds to the "long cycle" in the present embodiment, and the "second cycle 400 μm" corresponds to the "short cycle".

Here, when the long-period first fringe pattern W1 is generated, the grid plate moving mechanism 27 is driven and controlled to slide-displace the movable grid plate 26 in the X'axis direction, as shown in FIG. 9A. The other end (left end) of the light-shielding portion 32 on the movable grid plate 26 side in the X'axial direction is aligned with the position of one end (right end) of the light-shielding portion 32 on the fixed grid plate 25 side in the X'axis direction. To do.

As a result, the lattice unit 20 has a composite lattice pattern in which the lattice patterns 30 of the lattice plates 25 and 26 are superposed, and the width of the translucent portion in the X'axis direction is "400 (20 x 20) μm", X. A virtual lattice pattern is formed in which the width of the light-shielding portion in the axial direction is "400 (20 x 20) μm" and the ratio of the light-transmitting portion to the light-shielding portion is "1: 1".

Then, the first fringe pattern W1 having a first period of 800 μm is generated by this synthetic lattice pattern. By projecting the first fringe pattern W1 onto the printed circuit board 1, the cream solder 5 in the height range of 0 μm to 800 μm can be measured with an accuracy of “8 μm”.

Normally, the light passing through the lattice is not completely parallel light, but is caused by the diffraction action at the boundary between the translucent part and the light-shielding part, and the projected fringe pattern "bright part" and "dark part". An intermediate gradation region will be generated at the boundary portion. Therefore, the striped pattern W projected onto the printed circuit board 1 is a pattern light having a sinusoidal light intensity distribution along a direction (X-axis direction) orthogonal to the transport direction (Y-axis direction) of the printed circuit board 1. (See FIG. 4).

However, in FIGS. 4 and 9, for the sake of simplicity, the intermediate gradation region is omitted, and the stripe pattern W is illustrated by a light-dark binary stripe pattern. Therefore, the notation of the widths of the bright portion and the dark portion of the fringe pattern W in FIG. 9 indicates the widths of the light-transmitting portion and the light-shielding portion in the composite lattice pattern (the same applies to FIGS. 10 to 14 described later).

On the other hand, when the second fringe pattern W2 having a short cycle is generated, the grid plate moving mechanism 27 is driven and controlled to slide and displace the movable grid plate 26 in the X'axis direction, as shown in FIG. 9B. The light-shielding portion 32 on the movable grid plate 26 side is aligned with the center portion in the X'axis direction of the translucent portion 31 on the fixed grid plate 25 side.

As a result, the lattice unit 20 has a composite lattice pattern in which the lattice patterns 30 of the lattice plates 25 and 26 are superposed, and the width of the translucent portion in the X'axis direction is "200 (10 x 20) μm", X. A virtual lattice pattern is formed in which the width of the light-shielding portion in the axial direction is "200 (10 x 20) μm" and the ratio of the light-transmitting portion to the light-shielding portion is "1: 1".

Then, the second fringe pattern W2 having a second period of 400 μm is generated by this synthetic lattice pattern. By projecting the second fringe pattern W2 onto the printed circuit board 1, the cream solder 5 in the height range of 0 μm to 400 μm can be measured with an accuracy of “4 μm”.

In the present embodiment, an example in which the projection magnification of the projection optical system (projection lens unit 21) is set to 1 is shown, but the projection magnification is not limited to this. The size of the grid pattern 30 on the grid plates 25 and 26 (the size of the composite grid pattern on the exit surface 20b of the grid unit 20) and the size of the striped pattern W projected on the printed circuit board 1 change depending on the projection magnification. To do.

Further, as shown in FIG. 7, the grid unit moving mechanism 22 for displacement of the grid unit 20 is provided on one side (left side in FIG. 7) of the grid unit 20 in the X'axis direction, and the grid unit 20 is placed on the other side (FIG. 7). As a spring member 22a as an urging means for urging toward (7 right side), and as a driving means provided on the other side of the lattice unit 20 in the X'axis direction and sliding and displacementing the lattice unit 20 along the X'axis direction. The piezo element 22b is provided, and is driven and controlled by the control device 13. The lattice unit moving mechanism 22 constitutes the pattern light displacement means in the present embodiment.

Returning to the description of FIG. 5, the projection lens unit 21 has an incident side lens 35 and an outgoing side lens 36, and both lenses 35 and 36 are configured as a bilateral telecentric optical system (bilateral telecentric lens).

Here, the incident side lens 35 collects the light (striped pattern W) emitted from the lattice unit 20, and has a telecentric structure in which the optical axis J1 and the main light beam are parallel to each other on the incident side.

The emitting side lens 36 is for forming an image of light (striped pattern W) transmitted through the incident side lens 35 on the printed substrate 1, and the optical axis J1 and the main ray are parallel to each other on the emitting side. It has a telecentric structure.

Further, in the projection device 14 according to the present embodiment, the optical axis J1 is focused so that the fringe pattern W projected on the printed circuit board 1 is in focus over the entire projection range (the same range as the imaging field of view K in the present embodiment). The grid unit 20 (optical axis J3) is set to be tilted with respect to the lattice unit 20 (see FIGS. 5 and 7).

Specifically, with respect to the printed circuit board 1, the exit surface (composite lattice surface) 20b of the lattice unit 20 and the main surface of the projection lens unit 21 are set so as to satisfy the conditions of Scheimpflug.

Here, the principle of Scheimpflug will be described with reference to FIG. The principle of Scheimpflug is that the plane S1 including the exit surface 20b of the grid unit 20 and the plane S2 including the main surface of the projection lens unit 21 are the same straight line C (a straight line perpendicular to the paper surface at the point C on FIG. 5). When intersecting above, the object surface S3 on which the stripe pattern W is projected in the focused state also intersects on the same straight line C. Therefore, the conditions based on the Scheimpflug principle are the plane S1 including the exit surface 20b of the lattice unit 20, the plane S2 including the main surface of the projection lens unit 21, and the surface (projection surface) of the printed circuit board 1. The included planes S3 intersect each other on the same straight line C.

Under the above configuration, in the projection device 14, the light emitted from the light source 19 is incident on the incident surface 20a of the lattice unit 20. The light transmitted through the lattice unit 20 is emitted as a striped pattern W from the exit surface 20b of the lattice unit 20. Then, it is projected onto the printed circuit board 1 via the projection lens unit 21. As a result, in the present embodiment, as shown in FIG. 4, the fringe pattern W parallel to the transport direction (Y-axis direction) of the printed circuit board 1 is projected.

As shown in FIG. 1, the camera 15 has an image pickup element 15a having a light receiving surface in which a plurality of light receiving elements are two-dimensionally arranged, and an image pickup field of the printed substrate 1 on which a striped pattern W is projected onto the image pickup element 15a. It has an image pickup lens unit 15b as an image pickup optical system for forming an image of K, and its optical axis J2 is set along a vertical direction (Z axis direction) perpendicular to the upper surface of the printed substrate 1. In this embodiment, a CCD area sensor is used as the image sensor 15a.

The image pickup lens unit 15b is composed of a two-sided telecentric lens (both-sided telecentric optical system) including an object-side lens, an aperture diaphragm, an image-side lens, and the like. However, in FIG. 1, for the sake of simplicity, the image pickup lens unit 15b is shown as one lens.

Here, the object-side lens collects the reflected light from the printed substrate 1, and has a telecentric structure in which the optical axis J2 and the main light beam are parallel to each other on the object-side. The image-side lens is for forming an image of light transmitted through the aperture diaphragm from the object-side lens on the light receiving surface of the image pickup element 15a, and has a telecentric structure in which the optical axis J2 and the main ray are parallel on the image side. Has.

The image data captured and acquired by the camera 15 is converted into a digital signal inside the camera 15 at any time, input to the control device 13 in the form of a digital signal, and stored in the image data storage device 44 described later. To. Then, the control device 13 performs image processing, arithmetic processing, and the like as described later based on the image data. The control device 13 constitutes the image processing means in the present embodiment.

Next, the electrical configuration of the control device 13 will be described with reference to FIG. FIG. 6 is a block diagram showing an electrical configuration of the substrate inspection device 10.

As shown in FIG. 6, the control device 13 includes a microcomputer 41 that controls the entire board inspection device 10, an input device 42 as an "input means" composed of a keyboard, a mouse, a touch panel, and the like, a CRT, a liquid crystal, and the like. A display device 43 as a "display means" having a display screen, an image data storage device 44 for storing image data captured and acquired by a camera 15, a three-dimensional measurement result obtained based on the image data, and the like. A calculation result storage device 45 for storing various calculation results, a setting data storage device 46 for storing various information such as Gerber data in advance, and the like are provided.

The microcomputer 41 includes a CPU 41a as a calculation means, a ROM 41b for storing various programs, a RAM 41c for temporarily storing various data such as calculation data and input / output data, and is electrically connected to the above devices 42 to 46 and the like. It is connected to the. Then, it has a function of performing input / output control of various data and signals with each of these devices 42 to 46 and the like.

The setting data storage device 46 stores information regarding a plurality of inspection ranges set on the printed circuit board 1 and the movement order of the imaging field of view K of the camera 15 with respect to these inspection ranges. Here, the "movement order of the imaging field of view K" defines the order in which the imaging field of view K of the camera 15 is moved with respect to the plurality of inspection ranges set on the printed circuit board 1.

The plurality of inspection ranges related to the printed circuit board 1 and the moving order of the imaging field of view K with respect to these are set automatically by a predetermined program in advance based on Gerber data or the like, or manually by an operator.

For example, in the example shown in FIG. 2, the movement order (inspection order) of the imaging field of view K is set starting from the inspection range in the upper right corner. In FIG. 2, the range surrounded by the two-dot chain line frame indicates the imaging field of view K (inspection range), and the circled numbers “1” to “15” in this frame indicate the inspection order. Further, in FIG. 2, the moving direction (moving path) of the imaging field of view K is indicated by a dotted arrow.

Next, the inspection routine of the printed circuit board 1 performed by the substrate inspection apparatus 10 will be described in detail. Such an inspection routine is executed by the control device 13 (microcomputer 41).

As described above, when the printed circuit board 1 carried into the substrate inspection device 10 is positioned and fixed at a predetermined inspection position, the control device 13 first executes the position detection process of the printed circuit board 1.

More specifically, the control device 13 detects a positioning mark (not shown) attached on the printed circuit board 1, and the position information (coordinates) of the detected mark and the position information of the mark stored in the Gerber data. Based on (coordinates), the position information (tilt, position deviation, etc.) of the printed circuit board 1 is calculated. As a result, the position detection process of the printed circuit board 1 is completed. Then, based on the position information of the printed circuit board 1, a correction process for correcting the deviation of the relative positional relationship between the inspection unit 12 (camera 15) and the printed circuit board 1 is executed.

After that, according to the inspection order stored in the setting data storage device 46, the movement process of moving the inspection unit 12 to the position corresponding to the “1st” inspection range on the printed circuit board 1 is executed.

During this time, the control device 13 executes a process of adjusting the cycle of the fringe pattern W projected on the "1st" inspection range to a cycle corresponding to the inspection range based on the Gerber data stored in the setting data storage device 46. To do.

As shown in FIG. 2, in the present embodiment, the “1st” inspection range is the control circuit unit PB, so here, the short-cycle second fringe pattern W2 is set.

When the movement process of the inspection unit 12 is completed and the imaging field of view K of the camera 15 is adjusted to the “1st” inspection range on the printed circuit board 1, the projection device 14 projects the second fringe pattern W2 to the printed circuit board. The inspection process related to the "1st" th inspection range on 1 is executed. The details of such inspection processing will be described later (the same applies to inspection processing related to other inspection ranges).

After that, when the inspection process related to the "1st" inspection range on the printed circuit board 1 is completed, the inspection unit 12 is inspected on the printed circuit board 1 according to the inspection order stored in the setting data storage device 46. Start the movement process to move to the position corresponding to the range.

During this time, the control device 13 executes a process of adjusting (changing) the cycle of the fringe pattern W projected on the "second" inspection range to the cycle corresponding to the inspection range, as described above.

As shown in FIG. 2, in the present embodiment, the “second” inspection range is the power circuit unit PA, so here, the long-period first fringe pattern W1 is set.

When the movement process of the inspection unit 12 is completed and the imaging field of view K of the camera 15 is adjusted to the “second” inspection range on the printed circuit board 1, the projection device 14 projects the first fringe pattern W1 to the printed circuit board. The inspection process related to the "2nd" inspection range on 1 is executed.

After that, when the inspection process related to the "2nd" inspection range on the printed circuit board 1 is completed, the inspection unit 12 is inspected on the printed circuit board 1 according to the inspection order stored in the setting data storage device 46. Start the movement process to move to the position corresponding to the range.

Similarly, the inspection process is executed for the "3rd" to "15th" inspection ranges on the printed circuit board 1 by the stripe pattern W (first stripe pattern W1 or second stripe pattern W2) corresponding to the inspection range. By doing so, the solder printing inspection for the entire printed circuit board 1 is completed.

Next, the inspection process performed in each inspection range of the printed circuit board 1 will be described. Such an inspection process is executed by the control device 13 (microcomputer 41).

In the present embodiment, the light intensity distribution is distributed by performing four imaging processes under the fringe pattern W having different phases while changing the phase of the fringe pattern W projected from the projection device 14 for each inspection range. Acquire four different types of image data. The details will be described below.

As described above, the control device 13 first drives and controls the X-axis moving mechanism 16 and the Y-axis moving mechanism 17 to move the inspection unit 12, and brings the imaging field of view K of the camera 15 into a predetermined inspection range of the printed circuit board 1. Align. At the same time, the grid unit 20 of the projection device 14 is moved and controlled, and the position of the grid unit 20 is set to a predetermined reference position (for example, the position of the phase “0 °”).

When the positioning of the grid unit 20 is completed, the control device 13 causes the light source 19 of the projection device 14 to emit light, projects a predetermined fringe pattern W (first fringe pattern W1 or second fringe pattern W2), and causes the camera 15 to emit light. Drive control is performed to execute the first imaging process under the fringe pattern W.

After that, the control device 13 turns off the light source 19 and executes the moving process of the grid unit 20 at the same time as the end of the first imaging process under the predetermined fringe pattern W. Specifically, the position of the grid unit 20 is moved from the reference position to a second position where the phase of the stripe pattern W is shifted by a quarter pitch (90 °).

When the movement process of the grid unit 20 is completed, the control device 13 causes the light source 19 to emit light, projects a predetermined fringe pattern W, and drives and controls the camera 15 to perform a second time under the fringe pattern W. Execute the imaging process.

After that, by repeating the same process, four types of image data having different light intensity distributions are acquired under the fringe pattern W having different phases by 90 ° (1/4 pitch). As a result, it is possible to acquire four types of image data in which the phase of the fringe pattern W having a sinusoidal light intensity distribution is shifted by 90 °.

Then, the control device 13 measures the cream solder 5 three-dimensionally (height of each coordinate) by a known phase shift method based on the four image data (four brightness values of each coordinate) acquired as described above. Measurement) is performed, and the measurement result is stored in the calculation result storage device 45.

Here, a known phase shift method will be described. The light intensities (luminances) I0, I1, I2, and I3 at predetermined coordinate positions on the printed circuit board 1 in the above four types of image data are represented by the following equations (1), (2), (3), and (4), respectively. be able to.

I0 = αsinθ + β ・ ・ ・ (1)
I1 = αsin (θ + 90 °) + β = αcosθ + β ・ ・ ・ (2)
I2 = αsin (θ + 180 °) + β = −αsinθ + β ・ ・ ・ (3)
I3 = αsin (θ + 270 °) + β = −αcosθ + β ・ ・ ・ (4)
However, α: gain, β: offset, θ: phase of the fringe pattern.

Then, by solving the above equations (1), (2), (3), and (4) with respect to the phase θ, the following equation (5) can be derived.

θ = tan ^-1 {(I0-I2) / (I1-I3)} ... (5)
By using the phase θ calculated in this way, the height (Z) at each coordinate (X, Y) on the printed circuit board 1 can be obtained based on the principle of triangulation.

Next, the control device 13 performs a quality determination process of the printing state of the cream solder 5 based on the three-dimensional measurement result (height data at each coordinate) obtained as described above. Specifically, the control device 13 is determined from the height reference plane determined for each inspection range (power circuit unit PA, control circuit unit PB) based on the measurement results of the inspection range obtained as described above. The amount of the printed cream solder 5 is calculated by detecting the printing range of the cream solder 5 which has become longer or longer and integrating the height of each portion within this range.

Subsequently, the control device 13 uses the data such as the position, area, height, or amount of the cream solder 5 thus obtained as reference data (gerba data, etc.) stored in the preset data storage device 46 in advance. A comparison judgment is made, and the quality of the printing state of the cream solder 5 in the inspection range is judged depending on whether or not the comparison result is within the permissible range.

After acquiring the four types of image data, the control device 13 moves the inspection unit 12 to the next inspection range while the quality determination process is being performed. After that, the above series of processes are repeated in the entire inspection range on the printed circuit board 1, so that the solder printing inspection for the entire printed circuit board 1 is completed.

As described in detail above, according to the present embodiment, the striped pattern W is projected onto the printed circuit board 1 from the projection device 14, and four types of image data having different phases of the striped pattern W are acquired. Based on these image data, three-dimensional measurement of the printed circuit board 1 is performed by the phase shift method.

At this time, in the present embodiment, the period (pitch) of the fringe pattern W projected from the projection device 14 is changed according to the degree of unevenness of the inspection range on the printed circuit board 1. Specifically, two types of fringe patterns W, a long-period first fringe pattern W1 and a short-period second fringe pattern W2, are switched and projected.

In particular, according to the projection device 14 according to the present embodiment, a liquid crystal grid or the like is used by using the grid unit 20 (lattice plates 25, 26) as the pattern generation unit that converts the light from the light source 19 into the fringe pattern W. It is possible to project a brighter striped pattern W than in the case.

Further, by providing the grid plate moving mechanism 27 for changing the relative positional relationship between the two grid plates 25 and 26, the period of the stripe pattern W projected on the printed circuit board 1 can be set without exchanging the grid plates 25 and 26. It can be changed.

Further, in the present embodiment, since inexpensive optical members such as the existing lattice plates 25 and 26 in which the lattice pattern 30 is printed on the base material 28 such as a glass plate can be used, expensive optics such as a liquid crystal element can be used. Compared with the case where the control element is used as the pattern generation unit, the manufacturing cost of the pattern generation unit can be suppressed.

In addition, unlike the case of using an existing liquid crystal element or the like, it is not necessary to control the pixels, the control can be simplified, and the generated fringe pattern W is microscopically discontinuous. Therefore, it is possible to project a more ideal striped pattern W onto the printed circuit board 1.

[Second Embodiment]
Next, the second embodiment will be described in detail with reference to FIG. Regarding the parts that overlap with the first embodiment, detailed description thereof will be omitted by using the same member names and the same reference numerals, and the following parts will be mainly different from the first embodiment. This will be described (the same applies to the third to sixth embodiments described later).

In the fixed grid plate 25 and the movable grid plate 26 according to the present embodiment, the width of the light transmitting portion 31 in the X'axis direction is "580 (29 × 20) μm", and the width of the light shielding portion 32 in the X'axis direction is "580 (29 x 20) μm". It is set to "220 (11 x 20) μm", and the ratio of the translucent portion 31 to the light-shielding portion 32 is "29:11" [see FIGS. 10 (a) and 10 (b)].

Then, when the long-period first fringe pattern W1 is generated, the grid plate moving mechanism 27 is driven and controlled to slide and displace the movable grid plate 26 in the X'axis direction, as shown in FIG. 10 (a). , Includes a predetermined range including one end (right end) in the X'axial direction of the light-shielding portion 32 on the fixed grid plate 25 side, and the other end (left end) in the X'axis direction of the light-shielding portion 32 on the movable grid plate 26 side. Align with the predetermined range so that they overlap in the X'axis direction.

As a result, the lattice unit 20 has a composite lattice pattern in which the lattice patterns 30 of the lattice plates 25 and 26 are superposed, and the width of the translucent portion in the X'axis direction is "400 (20 x 20) μm", X. A virtual lattice pattern is formed in which the width of the light-shielding portion in the axial direction is "400 (20 x 20) μm" and the ratio of the light-transmitting portion to the light-shielding portion is "1: 1". Then, the first fringe pattern W1 having a first period of 800 μm is generated by this synthetic lattice pattern.

On the other hand, when the second fringe pattern W2 having a short cycle is generated, the grid plate moving mechanism 27 is driven and controlled to slide and displace the movable grid plate 26 in the X'axis direction, as shown in FIG. 10 (b). The light-shielding portion 32 on the movable grid plate 26 side is aligned with the center portion in the X'axis direction of the translucent portion 31 on the fixed grid plate 25 side.

As a result, the lattice unit 20 has a composite lattice pattern in which the lattice patterns 30 of the lattice plates 25 and 26 are superposed, and the width of the translucent portion in the X'axis direction is "180 (9 x 20) μm", X. A virtual lattice pattern is formed in which the width of the light-shielding portion in the axial direction is “220 (11 × 20) μm” and the ratio of the light-transmitting portion to the light-shielding portion is “9:11”. Then, the second fringe pattern W2 having a second period of 400 μm is generated by this synthetic lattice pattern.

As described in detail above, according to the present embodiment, the same effects as those of the first embodiment are exhibited.

In particular, according to the present embodiment, when the long-period first fringe pattern W1 is generated, a part of the light-shielding portion 32 on the fixed grid plate 25 side and a part of the light-shielding portion 32 on the movable grid plate 26 side are formed. By overlapping, light leakage can be suppressed. As a result, a more ideal striped pattern W can be projected onto the printed circuit board 1.

In the present embodiment, when the short-period second fringe pattern W2 is generated, the ratio of the light-transmitting portion and the light-shielding portion in the composite lattice pattern is not exactly the same as "1: 1", but the ratio is If they are substantially the same as “9:11”, it is possible to generate a fringe pattern W having a sinusoidal light intensity distribution with sufficient accuracy for performing three-dimensional measurement by the phase shift method.

[Third Embodiment]
Next, the third embodiment will be described in detail with reference to FIG. In the fixed grid plate 25 and the movable grid plate 26 according to the present embodiment, the width of the light transmitting portion 31 in the X'axis direction is "600 (30 x 20) μm", and the width of the light shielding portion 32 in the X'axis direction is "600 (30 x 20) μm". It is set to "200 (10 x 20) μm", and the ratio of the translucent portion 31 to the light-shielding portion 32 is "3: 1" [see FIGS. 11 (a) and 11 (b)].

Then, when the long-period first fringe pattern W1 is generated, the grid plate moving mechanism 27 is driven and controlled to slide and displace the movable grid plate 26 in the X'axis direction, as shown in FIG. 11 (a). , Includes a predetermined range including one end (right end) in the X'axial direction of the light-shielding portion 32 on the fixed grid plate 25 side, and the other end (left end) in the X'axis direction of the light-shielding portion 32 on the movable grid plate 26 side. Align with the predetermined range so that they overlap in the X'axis direction.

As a result, the lattice unit 20 has a composite lattice pattern in which the lattice patterns 30 of the lattice plates 25 and 26 are superposed, and the width of the translucent portion in the X'axis direction is "420 (21 x 20) μm", X. A virtual lattice pattern is formed in which the width of the light-shielding portion in the axial direction is “380 (19 × 20) μm” and the ratio of the light-transmitting portion to the light-shielding portion is “21:19”. Then, the first fringe pattern W1 having a first period of 800 μm is generated by this synthetic lattice pattern.

On the other hand, when the second fringe pattern W2 having a short cycle is generated, the grid plate moving mechanism 27 is driven and controlled to slide and displace the movable grid plate 26 in the X'axis direction, as shown in FIG. 11 (b). The light-shielding portion 32 on the movable grid plate 26 side is aligned with the center portion in the X'axis direction of the translucent portion 31 on the fixed grid plate 25 side.

As a result, the lattice unit 20 has a composite lattice pattern in which the lattice patterns 30 of the lattice plates 25 and 26 are superposed, and the width of the translucent portion in the X'axis direction is "200 (10 x 20) μm", X. A virtual lattice pattern is formed in which the width of the light-shielding portion in the axial direction is "200 (10 x 20) μm" and the ratio of the light-transmitting portion to the light-shielding portion is "1: 1". Then, the second fringe pattern W2 having a second period of 400 μm is generated by this synthetic lattice pattern.

As described in detail above, according to the present embodiment, the same effects as those of the first and second embodiments are exhibited.

[Fourth Embodiment]
Next, the fourth embodiment will be described in detail with reference to FIG. The grid unit 20 according to the present embodiment is composed of one fixed grid plate 25 and two movable grid plates 26. Specifically, it includes a first movable grid plate 26A located above the fixed grid plate 25 and a second movable grid plate 26B located below the fixed grid plate 25.

In the fixed grid plate 25 and the movable grid plate 26 (26A, 26B) according to the present embodiment, the width of the translucent portion 31 in the X'axis direction is "1000 (50 x 20) μm", and the light shielding portion in the X'axis direction. The width of 32 is set to "200 (10 x 20) μm", and the ratio of the translucent portion 31 to the light-shielding portion 32 is "5: 1" [see FIGS. 12 (a) and 12 (b)].

Then, when the long-period first fringe pattern W1 is generated, the grid plate moving mechanism 27 is driven and controlled to slide and displace the first movable grid plate 26A and the second movable grid plate 26B in the X'axis direction, respectively. As shown in FIG. 12A, the X'axis of the light-shielding portion 32 on the first movable grid plate 26A side is located at one end (left end) in the X'axis direction of the light-shielding portion 32 on the fixed grid plate 25 side. The other end in the direction (right end) is aligned, and the light-shielding portion 32 on the second movable grid plate 26B side is positioned at the other end (right end) in the X'axis direction of the light-shielding portion 32 on the fixed grid plate 25 side. Align one end (left end) in the X'axis direction of.

As a result, the width of the translucent portion in the X'axis direction is "600 (30 x 20) μm" as a composite lattice pattern in which the lattice patterns 30 of the three lattice plates 25, 26A, and 26B are superposed on the lattice unit 20. , A virtual lattice pattern is formed in which the width of the light-shielding portion in the X'axis direction is "600 (30 x 20) μm" and the ratio of the light-transmitting portion to the light-shielding portion is "1: 1". Then, the first fringe pattern W1 having a first period of 1200 μm is generated by this synthetic lattice pattern.

On the other hand, when the second fringe pattern W2 having a short cycle is generated, the grid plate moving mechanism 27 is driven and controlled to slide and displace the first movable grid plate 26A and the second movable grid plate 26B in the X'axis direction, respectively. As shown in FIG. 12B, the light-shielding portion 32 on the first movable grid plate 26A side is moved from the light-shielding portion 32 on the fixed grid plate 25 side to one side (left side) in the X'axis direction by a predetermined amount [200 (10). × 20) μm] While separating, the light-shielding portion 32 on the second movable grid plate 26B side is moved from the light-shielding portion 32 on the fixed grid plate 25 side to the other side (right side) in the X'axis direction by a predetermined amount [200 (10 × 20). ) Μm] Separate.

As a result, the width of the translucent portion in the X'axis direction is "200 (10 x 20) μm" as a composite lattice pattern in which the lattice patterns 30 of the three lattice plates 25, 26A, and 26B are superposed on the lattice unit 20. , A virtual lattice pattern is formed in which the width of the light-shielding portion in the X'axis direction is "200 (10 x 20) μm" and the ratio of the light-transmitting portion to the light-shielding portion is "1: 1". Then, the second fringe pattern W2 having a second period of 400 μm is generated by this synthetic lattice pattern.

As described in detail above, according to the present embodiment, the same effects as those of the first embodiment are exhibited. In particular, according to the present embodiment, by using the three lattice plates 25, 26A and 26B, the difference in period between the long-period first fringe pattern W1 and the short-period second fringe pattern W2 can be increased. it can.

[Fifth Embodiment]
Next, the fifth embodiment will be described in detail with reference to FIG. In the fixed grid plate 25 and the movable grid plate 26 according to the present embodiment, the width of the light transmitting portion 31 in the X'axis direction is "500 (25 x 20) μm", and the width of the light shielding portion 32 in the X'axis direction is "500 (25 x 20) μm". It is set to "300 (15 x 20) μm", and the ratio of the translucent portion 31 to the light-shielding portion 32 is "5: 3" [see FIGS. 13 (a) and 13 (b)].

However, the light-shielding portion 32 in the present embodiment is composed of a plurality of portions having different transmittances. More specifically, a portion having a medium transmittance is provided between a portion having a high transmittance (translucent portion 31) and a portion having a low transmittance (a portion having a lower transmittance in the light-shielding portion 32). ing.

Specifically, a high light-shielding portion having a transmittance of 25% is provided in the "100 (5 x 20) μm" range of the central portion of the light-shielding portion 32 in the X'axial direction, and both sides of the high light-shielding portion in the X'axial direction are provided. In the "100 (5 x 20) μm" range, medium shading portions having a transmittance of 50% are provided. On the other hand, the transmittance of the translucent portion 31 in this embodiment is 100%.

Then, when the long-period first fringe pattern W1 is generated, the grid plate moving mechanism 27 is driven and controlled to slide and displace the movable grid plate 26 in the X'axis direction, as shown in FIG. 13 (a). , A predetermined range (a portion having a transmission rate of 50%) including one end (right end) of the light-shielding portion 32 on the fixed grid plate 25 side in the X'axis direction, and the X'axis direction of the light-shielding portion 32 on the movable grid plate 26 side, etc. Align the predetermined range (part with a transmission rate of 50%) including the end portion (left end portion) so as to overlap in the X'axis direction.

As a result, the lattice unit 20 has a composite lattice pattern in which the lattice patterns 30 of the lattice plates 25 and 26 are superposed, and the width of the translucent portion in the X'axis direction is "300 (15 x 20) μm", X. A virtual lattice pattern is formed in which the width of the light-shielding portion in the axial direction is “500 (25 × 20) μm” and the ratio of the light-transmitting portion to the light-shielding portion is “3: 5”.

However, the light-shielding portion of the composite lattice pattern has a high light-shielding portion having a transmittance of 25% in the "300 (15 × 20) μm" range at the center of the X'axis direction, and both sides of the high light-shielding portion in the X'axis direction. The "100 (5 x 20) μm" range is a light-shielding portion with a transmittance of 50%.

Then, the first fringe pattern W1 having a first period of 800 μm is generated by this synthetic lattice pattern.

On the other hand, when the second fringe pattern W2 having a short cycle is generated, the grid plate moving mechanism 27 is driven and controlled to slide and displace the movable grid plate 26 in the X'axis direction, as shown in FIG. 13 (b). The light-shielding portion 32 on the movable grid plate 26 side is aligned with the center portion in the X'axis direction of the translucent portion 31 on the fixed grid plate 25 side.

As a result, the lattice unit 20 has a composite lattice pattern in which the lattice patterns 30 of the lattice plates 25 and 26 are superposed, and the width of the translucent portion in the X'axis direction is "100 (5 x 20) μm", X. A virtual lattice pattern is formed in which the width of the light-shielding portion in the axial direction is “300 (15 × 20) μm” and the ratio of the light-transmitting portion to the light-shielding portion is “1: 3”.

However, the light-shielding portion of the synthetic lattice pattern has a high light-shielding portion having a transmittance of 25% in the "100 (5 × 20) μm" range at the center of the X'axis direction, and both sides of the high light-shielding portion in the X'axis direction. The "100 (5 x 20) μm" range is a light-shielding portion with a transmittance of 50%.

Then, the second fringe pattern W2 having a second period of 400 μm is generated by this synthetic lattice pattern.

As described in detail above, according to the present embodiment, the same effects as those of the first embodiment are exhibited. In particular, according to the present embodiment, the light-shielding portion 32 is composed of a plurality of portions having different transmittances, so that a more ideal fringe pattern W can be projected onto the printed circuit board 1.

[Sixth Embodiment]
Next, the sixth embodiment will be described in detail with reference to FIG. In the fixed grid plate 25 and the movable grid plate 26 according to the present embodiment, the width of the light transmitting portion 31 in the X'axis direction is "500 (25 x 20) μm", and the width of the light shielding portion 32 in the X'axis direction is "500 (25 x 20) μm". It is set to "300 (15 x 20) μm", and the ratio of the translucent portion 31 to the light-shielding portion 32 is "5: 3" [see FIGS. 14 (a) and 14 (b)].

However, the light-shielding portion 32 in the present embodiment is composed of a plurality of portions having different transmittances. More specifically, a portion having a medium transmittance is provided between a portion having a high transmittance (translucent portion 31) and a portion having a low transmittance (a portion having a lower transmittance in the light-shielding portion 32). ing.

Specifically, a medium light-shielding portion having a transmittance of 50% is provided in the "200 (10 x 20) μm" range of the central portion of the light-shielding portion 32 in the X'axial direction, and both sides of the medium light-shielding portion in the X'axial direction are provided. A low light-shielding portion having a transmittance of 75% is provided in each of the “50 (2.5 × 20) μm” ranges. On the other hand, the transmittance of the translucent portion 31 in this embodiment is 100%.

Then, when the long-period first fringe pattern W1 is generated, the grid plate moving mechanism 27 is driven and controlled to slide and displace the movable grid plate 26 in the X'axis direction, as shown in FIG. 14 (a). , A predetermined range (100 μm range) including one end (right end) of the light-shielding portion 32 on the fixed grid plate 25 side in the X'axis direction, and the other end (left end) of the light-shielding portion 32 on the movable grid plate 26 side in the X'axis direction. The predetermined range (100 μm range) including the portion) is aligned so as to overlap in the X'axis direction.

As a result, the lattice unit 20 has a composite lattice pattern in which the lattice patterns 30 of the lattice plates 25 and 26 are superposed, and the width of the translucent portion in the X'axis direction is "300 (15 x 20) μm", X. A virtual lattice pattern is formed in which the width of the light-shielding portion in the axial direction is “500 (25 × 20) μm” and the ratio of the light-transmitting portion to the light-shielding portion is “3: 5”.

However, the light-shielding portion of the synthetic lattice pattern has a high light-shielding portion having a transmittance of 38% in the "100 (5 x 20) μm" range at the center of the X'axis direction, and both sides of the high light-shielding portion in the X'axis direction. The "150 (7.5 x 20) μm" range is a medium light-shielding part with a transmittance of 50%, and the outer "50 (2.5 x 20) μm" range is a low-light-shielding part with a transmittance of 75%. It has become.

Then, the first fringe pattern W1 having a first period of 800 μm is generated by this synthetic lattice pattern.

On the other hand, when the second fringe pattern W2 having a short cycle is generated, the grid plate moving mechanism 27 is driven and controlled to slide and displace the movable grid plate 26 in the X'axis direction, as shown in FIG. 14 (b). The light-shielding portion 32 on the movable grid plate 26 side is aligned with the center portion in the X'axis direction of the translucent portion 31 on the fixed grid plate 25 side.

As a result, the lattice unit 20 has a composite lattice pattern in which the lattice patterns 30 of the lattice plates 25 and 26 are superposed, and the width of the translucent portion in the X'axis direction is "100 (5 x 20) μm", X. A virtual lattice pattern is formed in which the width of the light-shielding portion in the axial direction is “300 (15 × 20) μm” and the ratio of the light-transmitting portion to the light-shielding portion is “1: 3”.

However, the light-shielding portion of the synthetic lattice pattern has a medium light-shielding portion having a transmittance of 50% in the "200 (10 x 20) μm" range at the center of the X'axial direction, and both sides of the medium-light-shielding portion in the X'axis direction. Each of the "50 (2.5 x 20) μm" ranges is a low light-shielding portion having a transmittance of 75%.

Then, the second fringe pattern W2 having a second period of 400 μm is generated by this synthetic lattice pattern.

As described in detail above, according to the present embodiment, the same effects as those of the first and fifth embodiments are exhibited.

The content is not limited to the description of the above embodiment, and may be implemented as follows, for example. Of course, other application examples and modification examples not illustrated below are also possible.

(A) In each of the above embodiments, the projection device and the three-dimensional measuring device of the present invention are embodied in a substrate inspection device 10 for inspecting the printed state of the cream solder 5 printed on the printed circuit board 1. The present invention is not limited to this, and may be embodied in a device for inspecting other objects such as an electronic component mounted on a printed circuit board. Of course, the configuration may be such that three-dimensional measurement is performed using an object different from the printed circuit board as the object to be measured.

(B) In each of the above embodiments, the printed circuit board 1 in which the power circuit unit PA and the control circuit unit PB are mixed is used as an object to be measured, and the power circuit unit PA on the printed circuit board 1 has a long-period first stripe. A pattern W1 is projected to perform three-dimensional measurement, and a short-period second fringe pattern W2 is projected onto the control circuit unit PB to perform three-dimensional measurement. The cycle of the stripe pattern W is switched according to the degree of unevenness.

Not limited to this, a printed circuit board having only the power circuit unit PA is used as an object to be measured, and only the long-period first fringe pattern W1 is projected onto the printed circuit board to perform three-dimensional measurement, and only the control circuit unit PB is provided. The striped pattern W is used as the object to be measured, and the striped pattern W is projected according to the type of the printed circuit board manufactured on the production line, such as projecting only the second striped pattern W2 with a short cycle to perform three-dimensional measurement. It may be configured to switch the period of.

Further, the power circuit unit PA may be configured to project both the long-period first fringe pattern W1 and the short-period second fringe pattern W2 in a plurality of ways, and combine the two to perform three-dimensional measurement. Good. As a result, although the measurement time is increased, the dynamic range can be expanded without degrading the height resolution.

(C) In each of the above embodiments, four types of image data in which the phases of the fringe pattern W differ by 90 ° are acquired in performing three-dimensional measurement by the phase shift method. The phase shift amount is not limited to these. Other phase shift counts and phase shift amounts that can be three-dimensionally measured by the phase shift method may be adopted. For example, a configuration may be configured in which three types of image data having different phases of 120 ° or 90 ° are acquired and three-dimensional measurement is performed.

(D) In each of the above embodiments, pattern light having a sinusoidal light intensity distribution is projected as the fringe pattern W in performing three-dimensional measurement by the phase shift method, but the present invention is not limited to this. The striped pattern W may be configured to project pattern light having a non-sinusoidal light intensity distribution such as a rectangular wave shape or a triangular wave shape.

However, the measurement accuracy is better when the pattern light having a sinusoidal light intensity distribution is projected and the three-dimensional measurement is performed than when the pattern light having a non-sinusoidal light intensity distribution is projected and the three-dimensional measurement is performed. Therefore, from the viewpoint of improving the measurement accuracy, it is preferable to have a configuration in which pattern light having a sinusoidal light intensity distribution is projected to perform three-dimensional measurement.

(E) In each of the above embodiments, the striped pattern W is projected onto the printed circuit board 1 and three-dimensional measurement is performed by the phase shift method. However, the present invention is not limited to this, and for example, the space code method and the moire method are used. , It may be configured to perform three-dimensional measurement by using another pattern projection method. However, when measuring a small measurement target such as cream solder 5, it is more preferable to adopt a measurement method with high measurement accuracy such as a phase shift method.

(F) In each of the above embodiments, the inspection unit 12 (projection device 14 and camera 15) is sequentially moved with respect to a plurality of inspection ranges on the printed circuit board 1 fixed at a predetermined position, whereby the entire area of the printed circuit board 1 is covered. It is configured to perform inspection. Not limited to this, the entire printed circuit board 1 may be inspected by moving the printed circuit board 1 with the inspection unit 12 fixed.

Further, in each of the above embodiments, the projection device 14 is provided with a grid unit moving mechanism 22 that displaces the grid unit 20, so that the inspection unit 12 and the printed circuit board 1 are not moved relative to each other, and the printed circuit board is fixed at a predetermined position. The structure is such that the relative positional relationship between the substrate 1 and the striped pattern W projected on the substrate 1 is changed (phase shift), but the striped pattern W and the printed circuit board 1 are relatively displaced (pattern optical displacement means). Is not limited to the above embodiment.

For example, as described above, when the period of the fringe pattern W to be projected is not switched over the entire printed circuit board, the printed circuit board is continuously moved by a conveyor or the like, or the inspection unit 12 is continuously moved with respect to the fixed printed circuit board. As a result, the relative positional relationship between the printed circuit board and the fringe pattern W projected on the printed circuit board may be changed (phase shift).

(G) In each of the above embodiments, the light source 19 is composed of a halogen lamp that emits white light. Not limited to this, a configuration using another light source such as a white LED may be used.

(H) The configuration of the pattern generation unit is not limited to the grid unit 20 according to each of the above embodiments.

For example, in each of the above embodiments, the fixed grid plate 25 and the movable grid plate 26 are housed in the translucent main body case portion 24, but the present invention is not limited to this, and the fixed grid is not limited to this, for example, by means of a frame or the like. The plate 25, the movable grid plate 26, and the like may be unitized.

In each of the above embodiments, one fixed grid plate 25 and one or two movable grid plates 26 are provided, but the present invention is not limited to this, and four or more grid plates are opposed to each other. It may be configured so as to do so.

Further, all the lattice plates may be movable lattice plates. For example, a first movable lattice plate and a second movable lattice plate may be provided, and the relative positional relationship between the two may be changed by moving each of them.

(I) In the grid unit 20 according to each of the above embodiments, a long-period first fringe pattern W1 is generated corresponding to the power circuit unit PA on the printed circuit board 1, and is short corresponding to the control circuit unit PB. Although the configuration is such that the second fringe pattern W2 of the period is generated, the number (type) of the fringe pattern W generated by the lattice unit 20 and the specific period are not limited to each of the above embodiments. ..

For example, the configuration may be such that three or more types of stripe patterns W having different cycles can be generated according to the degree of unevenness of the inspection range on the printed circuit board 1.

(J) The configuration relating to the grid moving means is not limited to the grid plate moving mechanism 27 according to each of the above embodiments. For example, the lattice plate moving mechanism 27 uses a solenoid 27b as a driving means for sliding displacement of the movable lattice plate 26, but the present invention is not limited to this, and other actuators such as a piezo element may be adopted.

(K) The configuration of the pattern optical displacement means is not limited to the grid unit moving mechanism 22 according to each of the above embodiments. For example, the lattice unit moving mechanism 22 uses a piezo element 22b as a driving means for sliding displacement of the lattice unit 20, but the present invention is not limited to this, and other actuators such as a solenoid may be adopted.

(L) The configuration of the lattice member and the lattice pattern is not limited to the fixed lattice plate 25, the movable lattice plate 26, and the lattice pattern 30 according to each of the above embodiments.

For example, the lattice plates 25 and 26 according to each of the above embodiments are arranged so that the printed surface of the lattice pattern 30 faces the incident side, but the present invention is not limited to this, and for example, the printed surface of the lattice pattern 30 may be arranged. The configuration may be arranged so as to face the exit side.

Further, the fixed lattice plate 25 and the movable lattice plate 26 may be arranged so that the printed surfaces of the lattice pattern 30 face each other, or the non-printed surfaces of the lattice pattern 30 may be arranged so as to face each other. It may be a configured configuration. It is preferable to arrange the printed surfaces of the lattice pattern 30 so as to face each other in terms of facilitating focusing of the striped pattern W.

Although not particularly mentioned in each of the above embodiments, the fixed grid plate 25 and the movable grid plate 26 may be arranged in a contact state as shown in FIG. 7, or as shown in FIG. 8 and the like. It may be arranged in a state of being separated (close to) from each other.

(M) In the lattice plates 25 and 26 according to each of the above embodiments, the light-shielding portion 32 is formed on a base material 28 formed in a flat plate shape or a film shape by a predetermined translucent material (for example, glass or acrylic resin). The lattice pattern 30 is formed by being printed (deposited).

The present invention is not limited to this, and the lattice pattern may be formed by another method such as laser processing.

Further, a lattice plate or the like in which a lattice pattern is formed by processing an opaque resin, metal or the like to form an opening such as a slit may be adopted.

Further, the transmittance of the light transmitting portion 31 and the light shielding portion 32 is not limited to each of the above embodiments. For example, the transmittance of the light transmitting portion 31 is not limited to 100%, and may be about 95%.

In each of the above embodiments, the grid patterns 30 formed on the fixed grid plate 25 and the movable grid plate 26 are the same. Not limited to this, if a plurality of stripe patterns W having different periods can be generated by these lattice plates 25 and 26, the lattice patterns 30 formed on these lattice plates 25 and 26 do not have to be the same.

Further, the specific size of the lattice pattern 30, such as the width of the light transmitting portion 31 and the light shielding portion 32, is not limited to each of the above embodiments.

(N) The configuration related to the projection optical system is not limited to the projection lens unit 21 according to each of the above embodiments.

For example, the projection lens unit 21 according to each of the above embodiments has an incident side lens 35 and an outgoing side lens 36, and both lenses 35 and 36 are configured as a bilateral telecentric optical system (bilateral telecentric lens). Not limited to this, an object-side telecentric lens (object-side telecentric optical system) may be adopted as the projection lens unit 21. Further, the configuration may not have a telecentric structure.

(O) The imaging means is not limited to the camera 15 of the above embodiment. For example, in the above embodiment, the CCD area sensor is adopted as the image sensor 15a, but the present invention is not limited to this, and for example, a CMOS area sensor or the like may be adopted.

Further, the image pickup lens unit 15b is composed of both sides telecentric lenses (both sides telecentric optical system). Not limited to this, an object-side telecentric lens (object-side telecentric optical system) may be adopted as the image pickup lens unit 15b. Further, the configuration may not have a telecentric structure.

(P) In the projection device 14 according to each of the above embodiments, the exit surface 20b of the lattice unit 20 and the main surface of the projection lens unit 21 are set so as to satisfy the conditions of Scheimpflug with respect to the printed circuit board 1.

Not limited to this, depending on the focusing state of the fringe pattern W over the entire projection range, it may not necessarily be set so as to satisfy the conditions of Scheimpflug.

Further, it is preferable that the above-mentioned Scheimpflug condition takes into consideration the arrangement configuration of the lattice plates 25 and 26 and the like.

Since the composite lattice pattern formed on the exit surface 20b of the lattice unit 20 is a lattice pattern in which the lattice patterns 30 of the lattice plates 25 and 26 are overlapped, it is not necessary to consider the arrangement configuration of the lattice plates 25 and 26. If the emission surface 20b of the lattice unit 20 and the main surface of the projection lens unit 21 are arranged so as to satisfy the conditions of Scheimpflug, there is a possibility that a slight error may occur.

1 ... Printed circuit board, 5 ... Cream solder, 10 ... Board inspection device, 12 ... Inspection unit, 13 ... Control device, 14 ... Projection device, 15 ... Camera, 19 ... Light source, 20 ... Lattice unit, 21 ... Projection lens unit, 22 ... Lattice unit moving mechanism, 25 ... Fixed grid plate, 26 ... Movable grid plate, 27 ... Lattice plate moving mechanism, 30 ... Lattice pattern, 31 ... Translucent part, 32 ... Shading part, J1 ... Optical axis of projection device, J3 ... Optical axis of the grid unit, PA ... Power circuit unit, PB ... Control circuit unit, W (W1, W2) ... Striped pattern.

Claims (9)

A projection device that projects a predetermined pattern of light onto a predetermined object to be measured when performing three-dimensional measurement on the object to be measured.
A light source that emits a predetermined amount of light,
A pattern generator that converts light incident from the light source into pattern light and emits it.
It is provided with a projection optical system that forms an image of pattern light emitted from the pattern generation unit on the object to be measured.
The pattern generator
A plurality of lattice members having a lattice pattern in which light-transmitting portions that transmit light at a predetermined transmittance and light-shielding portions that block at least a part of light are alternately arranged in the first direction are orthogonal to the first direction. In addition to being arranged so as to face each other in the second direction
By providing a lattice moving means capable of changing the relative positional relationship of the plurality of lattice members with respect to the first direction.
A projection device characterized in that the period of pattern light projected on the object to be measured can be changed. The projection device according to claim 1, wherein the lattice patterns formed on the plurality of lattice members are the same. The pattern generator
The light-shielding portion of the lattice pattern in one of the two lattice members facing each other in the second direction and the light-shielding portion of the lattice pattern in the other lattice member are connected in the first direction. By arranging the two lattice members, a long-period pattern light can be generated.
By arranging the two lattice members so that the light-shielding portion of the lattice pattern in the one lattice member and the light-shielding portion of the lattice pattern in the other lattice member are separated from each other in the first direction, the two lattice members are shortened. The projection device according to claim 1 or 2, wherein the projection device is configured to be capable of generating a periodic pattern light. The pattern generator
The position of the end of the light-shielding portion of the lattice pattern on one of the lattice members on the one-sided end in the first direction and the position of the end of the light-shielding portion of the lattice pattern on the other lattice member on the other-side of the first direction are first. The projection device according to claim 3, wherein the two lattice members are arranged so as to be in the same position in the same direction so that the long-period pattern light can be generated. The pattern generator
The predetermined range including the one end portion of the light-shielding portion of the lattice pattern in the one lattice member in the first direction and the predetermined range including the other end portion of the light-shielding portion of the lattice pattern in the other lattice member in the first direction are described above. The projection device according to claim 3, wherein the two lattice members are arranged so as to overlap each other in the first direction so that the long-period pattern light can be generated. The plurality of lattice members according to claims 1 to 5, wherein the plurality of lattice members are composed of one fixed fixed lattice member and at least one movable lattice member provided so as to be relatively displaceable with respect to the fixed lattice member. The projection device according to any one. The projection device according to any one of claims 1 to 6, wherein the light-shielding portion is composed of a plurality of portions having different transmittances. The projection device according to any one of claims 1 to 7, wherein as the pattern light, a pattern light having a striped light intensity distribution can be projected. The projection device according to any one of claims 1 to 8.
An imaging means capable of capturing a predetermined range of the object to be measured on which the pattern light is projected, and an imaging means.
A three-dimensional measuring device provided with an image processing means capable of performing three-dimensional measurement relating to the object to be measured based on the image data captured and acquired by the imaging means.

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