Visual inspection device

Abstract

A visual inspection device (1) comprises a light source (50), an image sensor (30), and a plate-like member (10) having light transmissivity, the visual inspection device (1) being characterized in that: the plate-like member (10) includes side surfaces opposing each other in a width direction, main surfaces opposing each other in a thickness direction orthogonal to the width direction, and end surfaces opposing each other in a length direction orthogonal to both the width direction and the thickness direction; the length direction is inclined relative to a horizontal plane orthogonal to a vertical direction; the width direction is substantially parallel to said horizontal plane; the main surfaces of the plate-like member include a sliding surface (10a) that is disposed on an upper side in the vertical direction and is for transporting components (100) along the length direction, and a non-sliding surface (10b) disposed on a lower side in the vertical direction; the light source (50) is provided on the non-sliding surface (10b) side of the plate-like member (10); the image sensor (30) is provided at a position facing the light source (50) with the plate-like member (10) interposed therebetween; and, among the components (100) transported on the sliding surface (10a), a plurality of the components (100) that are distributed in the width direction are simultaneously inspected by the image sensor (30).

Description

Visual inspection equipment

[0001] The present invention relates to a visual inspection apparatus.

[0002] In recent years, there has been a demand for mass production of electronic components, which has led to a demand for high-speed inspection of manufactured electronic components.

[0003] As an example of an inspection method for electronic components, Patent Document 1 describes a method in which an oblique light / transmitted illumination device and a television camera are provided along a chip component transport path, and the chip components are inspected by an image processing unit connected to the television camera that processes video signals to determine whether they are uninspectable, pass, or defective, and these chip components are sorted by operating a gate member for opening and closing the chute.

[0004] Japanese Patent Application Publication No. 1-249181

[0005] However, the method described in Patent Document 1 takes a long time for inspection, and a faster inspection method is desired.

[0006] The present invention has been made to solve the above problems, and has as its object to provide an appearance inspection apparatus that can inspect the appearance of parts at higher speeds than conventional apparatuses.

[0007] The visual inspection device of the present invention is an visual inspection device comprising a light source, an image sensor, and a light-transmitting plate-shaped member, wherein the plate-shaped member has side surfaces facing in the width direction, a main surface facing in the thickness direction perpendicular to the width direction, and end surfaces facing in the length direction perpendicular to the width direction and the thickness direction, and further, the length direction is inclined with respect to a horizontal plane perpendicular to the vertical direction, and the width direction is approximately parallel to the horizontal plane, the main surface of the plate-shaped member has a sliding surface arranged above the vertical direction for transporting parts along the length direction, and a non-sliding surface arranged below the vertical direction, the light source is provided on the non-sliding surface side of the plate-shaped member, and the image sensor is provided in a position opposite the light source via the plate-shaped member, and a plurality of parts distributed in the width direction among the parts transported on the sliding surface are simultaneously inspected by the image sensor.

[0008] According to the present invention, it is possible to provide a visual inspection apparatus that can inspect the visual appearance of a part at a higher speed than conventional methods.

[0009] Fig. 1 is a side view schematically showing an example of a visual inspection apparatus of the present invention, Fig. 2 is a view of the plate-like member of Fig. 1 as seen from the sliding surface side, and Fig. 3 is a side view schematically showing another example of a visual inspection apparatus of the present invention.

[0010] The visual inspection device of the present invention will be described below. However, the present invention is not limited to the following configuration, and can be appropriately modified and applied within the scope that does not change the gist of the present invention. Note that a combination of two or more of the individual desirable configurations of the present invention described below also constitutes the present invention.

[0011] In this specification, terms indicating the relationship between elements (e.g., "opposite," "orthogonal," etc.) and terms indicating the shape of elements (e.g., "rectangular," etc.) are not expressions that express only a strict meaning, but are expressions that include a substantially equal range, for example, a difference of a few percent.

[0012] The drawings shown below are schematic diagrams, and the dimensions, aspect ratios, and other scales may differ from those of the actual product.

[0013] [Visual inspection device] The visual inspection device of the present invention is an visual inspection device comprising a light source, an image sensor, and a light-transmitting plate-like member, wherein the plate-like member has side surfaces facing in a width direction, a main surface facing in a thickness direction perpendicular to the width direction, and end surfaces facing in a length direction perpendicular to the width direction and the thickness direction, and further, the length direction is inclined with respect to a horizontal plane perpendicular to the vertical direction, and the width direction is approximately parallel to the horizontal plane, and the main surface of the plate-like member has a sliding surface arranged above in the vertical direction for transporting parts along the length direction, and a non-sliding surface arranged below in the vertical direction, the light source is provided on the non-sliding surface side of the plate-like member, and the image sensor is provided at a position opposite the light source via the plate-like member, and a plurality of parts distributed in the width direction among the parts transported on the sliding surface are simultaneously inspected by the image sensor.

[0014] 1 is a side view showing a schematic diagram of an example of the visual inspection apparatus of the present invention, which includes a plate-like member 10, an image sensor 30, and a light source 50.

[0015] The plate-like member 10 has side surfaces facing the width direction W, a main surface facing the thickness direction T perpendicular to the width direction W, and end surfaces facing the length direction L perpendicular to the width direction W and the thickness direction T.

[0016] The main surfaces of the plate-like member 10 include a sliding surface 10a and a non-sliding surface 10b that face each other in the thickness direction T. The sliding surface 10a is a main surface that is located on the upper side in the vertical direction and transports the part 100 along the length direction L. The non-sliding surface 10b is a main surface that is located on the lower side in the vertical direction.

[0017] 1, the long arrow shown above the component 100 indicates the direction in which the component 100 is conveyed. The direction in which the component 100 is conveyed is parallel to the length direction L of the plate-like member 10.

[0018] 1, a straight line L' parallel to the length direction L of the plate-shaped member 10 is inclined at an angle θ with respect to the horizontal plane H. Therefore, it can be said that the length direction L of the plate-shaped member 10 is also inclined at an angle θ with respect to the horizontal plane H.

[0019] The light source 50 is disposed on the non-gliding surface 10b side of the plate-shaped member 10. Light is emitted from the light source 50 toward the plate-shaped member 10. In Fig. 1, the light emitted from the light source 50 is indicated by three arrows. The light source 50 may be in contact with the non-gliding surface 10b of the plate-shaped member 10, or may be separated from it.

[0020] The light source 50 and the image sensor 30 face each other across the plate-like member 10. That is, the image sensor 30 is provided at a position facing the light source 50 across the plate-like member 10.

[0021] The image sensor 30 is disposed at a position a predetermined distance away from the sliding surface 10 a of the plate-like member 10 , facing the light source 50 .

[0022] Fig. 2 is a view of the plate-shaped member of Fig. 1 as seen from the sliding surface side. The side surfaces of the plate-shaped member 10 include a first side surface 10c and a second side surface 10d that face each other in the width direction W. In Fig. 2, the direction in which the part 100 is conveyed is indicated by an arrow on the left side of the first side surface 10c of the plate-shaped member 10. That is, the part 100 is conveyed on the sliding surface 10a of the plate-shaped member 10 along the length direction L of the plate-shaped member 10.

[0023] As shown in FIG. 2, a plurality of parts 100 are distributed on the sliding surface 10a in the width direction W of the plate-like member 10.

[0024] As shown in FIG. 2, the sliding surface 10a of the plate-like member has a predetermined area (a rectangular area indicated by a dashed line in FIG. 2, an inspection area A) where the parts are inspected by the image sensor 30. ｉ Inspection Area A ｉ In this system, of the parts 100 conveyed on the sliding surface 10a, a plurality of parts 100 distributed in the width direction are simultaneously inspected by the image sensor 30. By simultaneously inspecting a plurality of parts 100 distributed in the width direction by the image sensor 30, the appearance of the parts can be inspected faster than before.

[0025] The orientation of the multiple parts 100 conveyed on the sliding surface 10a does not need to be uniform.

[0026] Next, each component of the visual inspection device of the present invention will be described.

[0027] (Plate-shaped member) The plate-shaped member has side surfaces facing in the width direction, a main surface facing in the thickness direction perpendicular to the width direction, and end surfaces facing in the length direction perpendicular to the width direction and the thickness direction.

[0028] The length direction of the plate-like member is inclined with respect to a horizontal plane perpendicular to the vertical direction. The inclination angle of the length direction of the plate-like member with respect to the horizontal plane is preferably 25° or more and 40° or less. In the appearance inspection device shown in Figure 1, the length direction L of the plate-like member is inclined with respect to the horizontal plane H by 30°.

[0029] The width direction of the plate-like member is preferably approximately parallel to the horizontal plane.

[0030] The main surface of the plate-like member has a sliding surface that is arranged on the upper side in the vertical direction and that conveys the parts along the length direction, and a non-sliding surface that is arranged on the lower side in the vertical direction. The parts are conveyed on the sliding surface.

[0031] The plate-shaped member has optical transparency, and may be made of any optically transparent material, such as resin or glass.

[0032] The width of the plate-like member is not particularly limited, but is preferably 40 mm to 80 mm, and is preferably 100 to 200 times the maximum dimension of the part to be conveyed.

[0033] The length of the plate-like member is not particularly limited, but is preferably 90 mm or more and 300 mm or less. The thickness of the plate-like member is not particularly limited, but is preferably 1 mm or more and 5 mm or less.

[0034] The static friction coefficient of the sliding surface of the plate-like member is preferably 0.15 or more and 0.2 or less. When the static friction coefficient of the sliding surface of the plate-like member is within the above range, the sliding property between the sliding surface and the parts is good, and the transportation (movement) of the parts on the sliding surface can be stabilized. The static friction coefficient of the sliding surface of the plate-like member can be measured in accordance with JIS K 7125 (1999).

[0035] The contact angle of the sliding surface of the plate-shaped member is preferably 1° or more and 10° or less, or 100° or more and 160° or less. When the contact angle of the sliding surface of the plate-shaped member is 1° or more and 10° or less, the sliding surface of the plate-shaped member becomes highly hydrophilic, and even if dirt or the like adheres, it can be easily removed with water or the like. When the contact angle of the sliding surface of the plate-shaped member is 100° or more and 160° or less, the sliding surface of the plate-shaped member becomes highly hydrophobic, and dirt is less likely to adhere to the sliding surface of the plate-shaped member, and even if dirt does adhere, it can be easily removed. The contact angle of the sliding surface of the plate-shaped member can be measured in accordance with the liquid drop method of JIS R 3257 (1999).

[0036] It is preferable that a coating layer is provided on the sliding surface of the plate-like member. When a coating layer is provided on the sliding surface, the sliding property between the sliding surface and the part is improved, and the transportation (movement) of the part on the sliding surface can be stabilized. In addition, it is easy to adjust the static friction coefficient and contact angle of the sliding surface to a desired range.

[0037] The coating layer may be a coating layer containing Si (silicon) or a coating layer containing F (fluorine), but a coating layer containing Si (silicon) is preferred. When a coating layer containing Si is provided on the sliding surface of the plate-like member, the transportation (movement) of the parts on the sliding surface is particularly likely to be stabilized.

[0038] Examples of the coating layer containing Si include a glass coating layer, etc. Examples of the coating layer containing fluorine include a coating layer made of a fluorine resin, etc.

[0039] The thickness of the coating layer is preferably 0.5 μm or more and 1.0 μm or less.

[0040] (Light Source) The light source is provided on the non-gliding surface side of the plate-like member. The light source may be in contact with the non-gliding surface of the plate-like member or may be separated from the non-gliding surface.

[0041] As the light source, various types of lighting such as dome lighting and ring lighting can be used, but bar lighting (also called line lighting) is preferred.

[0042] When the light source is a bar light (line light), it is preferable to arrange the light source so that the longitudinal direction of the light source is parallel to the width direction of the plate-like member. In this case, it is preferable that the length of the light source in the longitudinal direction is equal to or greater than the length of the plate-like member in the width direction.

[0043] The light source preferably includes at least a portion of the wavelength range, for example, from 400 nm to 1200 nm.

[0044] The light source may be any light source that emits at least some of the wavelengths described above, and examples thereof include a light emitting diode, a halogen lamp, an HID lamp, a low pressure discharge lamp, and a xenon lamp.

[0045] (Image Sensor) The image sensor is provided at a position facing the light source via a plate-like member.

[0046] The image sensor is preferably provided on the sliding surface side of the plate-like member so as not to come into contact with the sliding surface.

[0047] Among the parts being transported on the sliding surface, multiple parts distributed in the width direction are simultaneously inspected using an image sensor.

[0048] The image sensor acquires information about the parts being transported on the sliding surface, which can then be used to inspect the parts for cracks or chips (visual inspection).

[0049] The information about the component acquired by the image sensor depends on the type and arrangement of the image sensor, but may include, for example, the outer shape.

[0050] The following describes the case where an image sensor is used to acquire the outer shape of a part being transported on a sliding surface. In this case, the light source is located on the opposite side of the plate-like member from the image sensor, so the image sensor recognizes the area where the part exists as a dark area. Therefore, by recognizing the outline of the dark area, information about the outer shape of the part can be acquired.

[0051] By comparing the external shape of the part acquired by the image sensor with a predetermined external shape of the part, it is possible to determine whether the part has cracks, chips, etc. In addition, it is also possible to count the number of parts.

[0052] Examples of the image sensor include a charge-coupled device (CCD) image sensor and a complementary metal-oxide semiconductor (CMOS) image sensor, and the like. A plurality of these may be included.

[0053] The image sensor is preferably a line sensor, which is a sensor in which a plurality of image pickup elements are arranged in a line.

[0054] The total number of pixels in the width direction of the plate-like member of the imaging elements that make up the image sensor is preferably 6,000 or more. Also, the total number of pixels in the width direction of the plate-like member of the imaging elements that make up the image sensor is preferably 20,000 or less. If the total number of pixels in the imaging elements in the width direction of the plate-like member is 6,000 or more, good inspection accuracy can be achieved when multiple components distributed in the width direction are simultaneously inspected.

[0055] If the above configuration is satisfied, it becomes easy to simultaneously inspect one or more and 1000 or less components distributed in the width direction.

[0056] The total number of pixels in the length direction of the plate-like member of the imaging elements that make up the image sensor is preferably 1000 or more, and the total number of pixels in the length direction of the plate-like member of the imaging elements that make up the image sensor is preferably 2000 or less.

[0057] For example, if a line sensor is configured with six image sensors, each with 1,000 pixels in the vertical direction and 1,000 pixels in the horizontal direction, arranged in a line along the horizontal direction so that the direction in which the image sensors are arranged (horizontal direction) is parallel to the width direction of the plate-like member, then the total number of pixels in the image sensors in the width direction of the plate-like member is 6,000 pixels, and the total number of pixels in the length direction of the plate-like member is 1,000 pixels.Furthermore, a line sensor with eight image sensors arranged in a line along the horizontal direction is also possible.

[0058] The scan time of the imaging elements that make up the image sensor is preferably 35 μs or less.

[0059] The image sensor preferably performs visual inspection of at least one and at most 10,000 parts per second.

[0060] (Components) Components to be inspected by the visual inspection device of the present invention will be described. The components to be inspected by the visual inspection device of the present invention are not particularly limited, but examples thereof include electronic components such as multilayer ceramic capacitors, resistors, inductors, and thermistors.

[0061] The components are not limited to electronic components, but may be components that do not have internal electrodes, electronic components in the middle of manufacturing, etc.

[0062] The shape of the component is not particularly limited, but is preferably a substantially rectangular parallelepiped shape. The component may be provided with external electrodes, lead terminals, and the like.

[0063] The part may have, for example, a rectangular parallelepiped shape with a width dimension (W dimension) and a thickness dimension (T dimension) of 0.1 mm or more and 0.3 mm or less, and a length dimension (L dimension) of 0.2 mm or more and 0.6 mm or less.

[0064] [Other Configurations] The visual inspection device of the present invention may include configurations other than the plate-like member, image sensor, and light source described above. Examples of configurations other than the plate-like member, image sensor, and light source include a hopper, a parts feeder, a chute, a case, and a housing for accommodating these.

[0065] (Parts Feeder) The parts feeder supplies parts to the plate-like member. The parts feeder is preferably disposed upstream of the plate-like member.

[0066] The part feeder may be provided with a groove for conveying parts that extends in the direction of part conveyance. Since parts are conveyed along the groove, it becomes easier to control the direction of part conveyance. Furthermore, the groove makes it easier to form a line of parts on the top surface of the part feeder.

[0067] The part feeder may be provided with a plurality of the grooves along a direction substantially perpendicular to the direction of component conveyance. When a plurality of the grooves are provided, rows of components are formed on the top surface of the part feeder, the number of rows corresponding to the number of grooves. Therefore, the number of rows of components supplied from the part feeder can be adjusted by adjusting the number of grooves.

[0068] The parts feeder preferably supplies 10,000 to 1,000,000 parts to the plate-like member in 60 seconds. In this case, for example, it is preferable that the parts feeder has 100 to 150 grooves formed on its upper surface.

[0069] The parts feeder may be installed horizontally or at an angle.

[0070] The parts feeder may be a straight-advance type, a bowl type, or a combination of both the straight-advance type and the bowl type.

[0071] It is preferable that vibration is applied to the parts feeder, and that the parts are fed by the vibration. The mechanism for applying vibration to the parts feeder is preferably, for example, a piezoelectric element.

[0072] (Hopper) A hopper may be installed further upstream of the parts feeder. The hopper supplies parts to the parts feeder.

[0073] The approximate number of parts on the parts feeder may be detected by a camera or sensor, and when the number decreases, parts may be supplied from the hopper.

[0074] The size of the hopper is not particularly limited, but it is preferable that the hopper be large enough to store, for example, approximately 300,000 parts with a maximum length of approximately 0.6 mm, or approximately 600,000 parts with a maximum length of approximately 0.4 mm. The size of the storage section of the hopper that satisfies the above conditions is approximately 0.5 L.

[0075] (Case) A case for collecting parts that have passed through the plate-like member may be provided downstream of the plate-like member.

[0076] The shape of the case is not particularly limited, but may be, for example, a rectangular parallelepiped shape with a sliding lid on the surface.

[0077] The sliding lid may be linked to the placement of the case in a predetermined position. For example, the sliding lid may be closed before the case is placed in the predetermined position, but may be configured to open when the case is placed in the predetermined position. This configuration can prevent impurities other than the components from entering the case.

[0078] The case may have an RFID tag attached thereto, which may contain information such as whether or not a component is contained therein, and information about the component (model number, dimensions, quantity), as needed.

[0079] If an RFID tag is provided on the case, the visual inspection device preferably further includes an RFID reader / writer. The RFID reader / writer is preferably provided near the case. Information about the components to be housed in the case may be written to the RFID tag in advance, and after the case is installed, the information in the RFID tag may be read to verify whether the installed case is the case that will house the components to be housed. Alternatively, after the components are housed in the case, the fact that the components have been housed in the case and information about the housed components (model number, dimensions, quantity, etc.) may be written.

[0080] (Chute) A chute may be disposed between the plate-like member and the case to collect the parts discharged from the plate-like member and guide them to the case. By disposing the chute between the plate-like member and the case, the parts that have passed through the plate-like member can be reliably accommodated in the case.

[0081] The chute is preferably funnel-shaped with a large opening at the inlet located on the plate-like member side and a small opening at the outlet located on the case side.

[0082] The chute may have a vibration mechanism, which can prevent components from clogging the chute.

[0083] When a chute is provided between the plate-like member and the case, multiple cases may be installed. When multiple cases are installed, once all chips to be accommodated in a first case have been accommodated, the first case that has been accommodated may be moved, the connection between the chute and the first case may be released, and another empty case (second case) may be moved and connected to the chute. Alternatively, the chute may be moved instead of the first case, the connection between the chute and the first case may be released, and the chute may be connected to the second case.

[0084] 3 is a side view showing a schematic diagram of another example of the visual inspection apparatus of the present invention. The visual inspection apparatus 2 shown in FIG. 3 includes a plate-like member 10, an image sensor 30, a light source 50, and further includes a parts feeder 60, a hopper 70, a chute 80, and a case 90.

[0085] The parts 100 to be subjected to visual inspection are stored in a hopper 70. The parts 100 stored in the hopper 70 are supplied onto a part feeder 60. The parts 100 supplied onto the part feeder 60 are sequentially supplied onto the plate-like member 10 by the part feeder 60.

[0086] As the parts 100 supplied to the plate-like member 10 are conveyed on the sliding surface 10a, information is acquired by the image sensor 30 and an appearance inspection is performed. The method for inspecting the appearance of the parts is the same as the method for inspecting the appearance using the appearance inspection device 1 shown in Figures 1 and 2.

[0087] After the visual inspection is completed, the parts discharged from the downstream side of the plate-like member 10 are housed in a case 90 via a chute 80 .

[0088] The chute 80 is funnel-shaped with an inlet opening 80a larger than an outlet opening 80b. The outlet opening 80b of the chute 80 is located near the opening 90a of the case 90. Therefore, the component 100 that reaches the inlet opening 80a of the chute 80 is housed inside the case 90.

[0089] This specification discloses the following inventions:

[0090] The present disclosure (1) is an appearance inspection device comprising a light source, an image sensor, and a plate-like member having optical transparency, wherein the plate-like member has side surfaces facing in a width direction, a main surface facing in a thickness direction perpendicular to the width direction, and end surfaces facing in a length direction perpendicular to the width direction and the thickness direction, and further, the length direction is inclined with respect to a horizontal plane perpendicular to the vertical direction, and the width direction is approximately parallel to the horizontal plane, the main surface of the plate-like member has a sliding surface arranged above in the vertical direction and transporting parts along the length direction, and a non-sliding surface arranged below in the vertical direction, the light source is provided on the non-sliding surface side of the plate-like member, and the image sensor is provided at a position opposite the light source via the plate-like member, and the appearance inspection device is characterized in that of the parts transported on the sliding surface, a plurality of parts distributed in the width direction are simultaneously inspected by the image sensor.

[0091] The present disclosure (2) is the appearance inspection device according to the present disclosure (1), wherein a coating layer containing Si is formed on the sliding surface of the plate-like member.

[0092] The present disclosure (3) is an appearance inspection device according to the present disclosure (1) or (2), wherein the inclination angle of the length direction of the plate-like member relative to the horizontal plane is 25° or more and 40° or less.

[0093] 1, 2 Appearance inspection device 10 Plate-like member 10a Slide surface 10b Non-slide surface 30 Image sensor 50 Light source 60 Parts feeder 70 Hopper 80 Chute 90 Case 100 Part A ｉ Inspection area L: Length direction of plate-shaped member H: Horizontal plane T: Thickness direction of plate-shaped member W: Width direction of plate-shaped member

Claims

1. A visual inspection device comprising a light source, an image sensor, and a light-transmitting plate-like member, wherein the plate-like member has side surfaces opposing in a width direction, a main surface opposing in a thickness direction perpendicular to the width direction, and end surfaces opposing in a length direction perpendicular to the width and thickness directions, the length direction being inclined with respect to a horizontal plane perpendicular to the vertical direction, and the width direction being approximately parallel to the horizontal plane, the main surface of the plate-like member having a sliding surface arranged above in the vertical direction for transporting parts along the length direction, and a non-sliding surface arranged below in the vertical direction, the light source being provided on the non-sliding surface side of the plate-like member, and the image sensor being provided in a position opposite the light source across the plate-like member, and wherein a plurality of parts distributed in the width direction among the parts transported on the sliding surface are simultaneously inspected by the image sensor.

2. The visual inspection device according to claim 1, wherein a coating layer containing Si is formed on the sliding surface of the plate-like member.

3. An appearance inspection device according to claim 1 or 2, wherein the inclination angle of the length direction of the plate-like member relative to the horizontal plane is 25° or more and 40° or less.

Images