Code reader and image processing device

Abstract

The invention relates to a code reader and an image processing apparatus. The fixed code reader includes: a housing that is long in a first direction and has a light receiving window that transmits light that transversely intersects the first direction; an illumination part accommodated in the housing and forming an irradiation surface arranged side by side with the light receiving window in the first direction; an imaging unit having an image sensor mounted in the first direction; a mirror that turns back an optical path corresponding to the field of view of the imaging unit toward the light receiving window in the housing; and an attachment portion disposed on one side of the housing and configured to attach the housing to the outer frame.

Description

Technical Field

[0001] The present disclosure relates to a code reader that reads a code attached to a workpiece conveyed by a conveying device and an image processing device that processes an image obtained by capturing an image of the workpiece. Background Art

[0002] For example, this type of code reader is used when reading a code attached to a workpiece conveyed by a conveying device at a distribution site or the like. The code reader disclosed in Japanese Patent Laid-Open No. 2021-149656 includes an illumination unit that illuminates the workpiece and an imaging unit that receives reflected light from the workpiece and generates a code image. The illumination unit includes a plurality of illumination blocks, and a light receiving window that transmits reflected light from the workpiece is provided on the front side of the code reader in a portion surrounded by the illumination blocks.

[0003] The light transmitted through the light receiving window is received by an imaging unit arranged on the back side of the lighting block.

[0004] The code reader can be used in a state of being attached to an external frame. When the code reader is attached to the frame and used, when the code reader protrudes from the frame toward the conveyor side, there is a problem that the code reader interferes with the workpiece conveyed by the conveyor. Therefore, there is a demand to minimize the amount of protrusion of the code reader from the frame toward the conveyor side.

[0005] In this regard, in the code reader of Japanese Patent Laid-Open No. 2021-149656, a plurality of lighting blocks are arranged to surround the light receiving window, and the camera unit is arranged on the back side of the lighting block, so that the dimension in the depth direction becomes long. For this reason, if it is assumed that the code reader of Japanese Patent Laid-Open No. 2021-149656 is attached to the frame and operated, it can be considered that the code reader protrudes greatly toward the conveying device side. This may lead to a reduction in the degree of freedom of installation of the code reader. Summary of the invention

[0006] The present disclosure has been made in view of such a point, and an object of the present disclosure is to reduce the protrusion amount of the code reader from the frame to the conveying device side to improve the degree of freedom of installation when the code reader is attached to an external frame and used.

[0007] In order to achieve the above-mentioned object, in the present aspect, a fixed-type code reader can be assumed, which is configured to be usable in a state of being attached to an external frame and reads a code attached to a workpiece conveyed by a conveying device. The code reader includes: a housing having a long side extending in a first direction and having a light receiving window for transmitting light that intersects the first direction transversely; an illumination unit housed in the housing and forming an illumination surface arranged side by side with the light receiving window along the first direction, the illumination surface being used to illuminate a workpiece with illumination light; an imaging unit including an image sensor and a lens, the image sensor having a two-dimensional light receiving surface and being mounted in the housing toward the first direction, the lens projecting an image corresponding to a code attached to the workpiece onto the light receiving surface of the image sensor in the housing; a mirror for folding an optical path corresponding to a field of view of the imaging unit in the housing in the direction of the light receiving window; a decoder for performing decoding processing of the code attached to the workpiece based on an image generated by the imaging unit; and an attachment unit disposed on a side of the housing different from the side of the light receiving window and configured to attach the housing to the external frame.

[0008] According to this configuration, since the housing is long in the first direction, for example, the housing arranged so that the longitudinal direction of the outer frame coincides with the first direction of the housing can be attached to the outer frame by the attachment portion. In this housing, since the irradiation surface of the illumination light formed by the illumination portion is aligned with the light receiving window along the first direction, the dimension of the housing in this direction is shortened when the optical axis direction of the illumination light irradiating the code is taken as a reference. Therefore, the protrusion amount of the code reader from the outer frame to the conveying device side is reduced.

[0009] A communication interface may be provided, the communication interface being arranged at an end of the housing in the first direction and being configured to transmit information related to a result of a decoding process using the decoder. In this case, since the direction in which the communication line is connected to the communication interface is along the first direction, the protrusion amount of the code reader including the communication line toward the conveying device side is reduced.

[0010] As described above, in the case where the code reader is attached to the external frame and used, the protrusion amount of the code reader from the frame to the conveying device side is reduced, so that the degree of freedom of installation can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a perspective view for explaining the operation of the code reader according to the embodiment of the present invention;

[0012] Figure 2 This is a front view illustrating the installation state of the code reader;

[0013] Figure 3 It is the block diagram of the code reader;

[0014] Figure 4 is a schematic diagram illustrating the relationship between a Scheimpflug optical system and a focal plane;

[0015] Figure 5 It is a stereogram of a code reader;

[0016] Figure 6 This is the front view of the code reader;

[0017] Figure 7 This is the bottom view of the code reader;

[0018] Figure 8 is a perspective view illustrating a code reader in a state where a box-shaped housing is removed;

[0019] Fig. 9 is an enlarged cross-sectional view of the mating portion between the box-shaped housing and the cover-shaped housing;

[0020] Fig.10 is an enlarged cross-sectional view of the mating portion between the box-shaped housing and the window frame;

[0021] Fig.11 is a cross-sectional view of a first lighting unit;

[0022] Fig.12 is a longitudinal cross-sectional view of the cover-shaped housing in the left-right direction;

[0023] Fig.13 is a longitudinal cross-sectional view of the cover-shaped housing in the depth direction;

[0024] Fig.14 is a perspective view of a lens holder;

[0025] Fig.15 is the state where the sensor substrate is removed and corresponds to Fig.14 's picture;

[0026] Fig.16 is the state corresponding to the sensor holder being removed. Fig.14 's picture;

[0027] Fig.17 is a diagram for explaining a state in which an image of the bottom surface of a workpiece being conveyed is captured;

[0028] Fig.18 is a flowchart illustrating an example of a series of processes from capturing an image to outputting a reading result;

[0029] Fig.19 is a side view illustrating an example of a code reader being attached to a frame;

[0030] Fig. 20 is the corresponding value at different angles Fig.19's picture;

[0031] Fig.21 is a front view of the state attached to the frame;

[0032] Fig. 22 is a bottom view of the housing with the bracket;

[0033] Fig.23 is a side view illustrating an installation example in which the optical axis is orthogonal to the reference surface;

[0034] Fig.24 is a side view illustrating an installation example using a mirror;

[0035] Fig.25 is a side view illustrating a comparison of mounting examples in a case where a bracket is attached to different sides;

[0036] Fig.26 is a diagram illustrating a schematic structure of a code reader according to a first example of another embodiment;

[0037] Fig. 27 is a diagram illustrating the field of view and depth of a code reader according to a first example;

[0038] Fig.28 is a diagram illustrating the field of view and depth of a code reader according to a second example;

[0039] Fig.29 is a diagram illustrating a schematic structure of a code reader according to a third example;

[0040] Fig.30 is a diagram illustrating a schematic structure of a code reader according to a fourth example; and

[0041] Fig.31 is a diagram illustrating the field of view and depth of a code reader according to the fifth example. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its application or use.

[0043] Figure 1 1A, 1B, 1C and 1D according to an embodiment of the present invention. Figure 2 1 is a front view showing the installation state of the code readers 1A, 1B, 1C and 1D. In this example, a case where a plurality of code readers 1A, 1B, 1C and 1D are used at a distribution site where a plurality of workpieces W are handled is shown. At the distribution site, a conveying device B is installed to sequentially convey a plurality of workpieces W in a predetermined conveying direction. The conveying direction of the workpieces W is determined by Figure 1The arrow A indicates that. Therefore, Figure 1 The right side of is the upstream side in the conveying direction, and Figure 1 The left side is the downstream side in the conveying direction.

[0044] The conveying device B has a plurality of conveying mechanisms B1 and B2. The conveying mechanisms B1 and B2 are composed of, for example, a belt conveyor, a roller conveyor, etc., and are provided with an upstream conveying mechanism B1 and a downstream conveying mechanism B2. The upper surfaces of the upstream conveying mechanism B1 and the downstream conveying mechanism B2 are conveying surfaces. In the present embodiment, the conveying direction of the workpiece W is defined as the Y direction, the direction on the conveying surface perpendicular to the Y direction is defined as the X direction, and the direction perpendicular to both the X direction and the Y direction is defined as the Z direction. In the distribution site, the X direction and the Y direction are usually approximately horizontal, but the Y direction can be inclined relative to the horizontal plane. The X direction can be referred to as the width direction of the conveying mechanisms B1 and B2, or can be referred to as the longitudinal direction of the gap of the conveying device B. In addition, the Z direction can also be referred to as the height direction (up and down direction). Note that the definition of the direction is for convenience of explanation and does not limit the direction during use.

[0045] The upstream conveying mechanism B1 and the downstream conveying mechanism B2 are arranged at intervals in the conveying direction. The size (dimension) of the interval between the upstream conveying mechanism B1 and the downstream conveying mechanism B2 is not particularly limited, but is set so that the smallest workpiece W to be conveyed is smoothly transferred from the upstream conveying mechanism B1 to the downstream conveying mechanism B2 without falling from the gap. The dimension of the gap in the longitudinal direction (dimension in the X direction) is approximately the same as the width (dimension in the X direction) of the conveying mechanisms B1 and B2, but this is also not particularly limited.

[0046] The upstream conveying mechanism B1 and the downstream conveying mechanism B2 are supported on the floor surface C ( Figure 2 Therefore, since the conveying surfaces of the upstream conveying mechanism B1 and the downstream conveying mechanism B2 are located at positions separated upward from the ground C by a predetermined size, a space can be formed below the upstream conveying mechanism B1 and the downstream conveying mechanism B2.

[0047] although Figure 1 and Figure 2 An example in which four code readers 1A, 1B, 1C, and 1D are used in operation is illustrated, but the number of code readers in operation is not limited to four, and may be any number of three or less, or five or more. The code reader 1A is referred to as a first code reader 1A, the code reader 1B is referred to as a second code reader 1B, the code reader 1C is referred to as a third code reader 1C, and the code reader 1D is referred to as a fourth code reader 1D.

[0048] The first to fourth code readers 1A, 1B, 1C, and 1D are configured to be usable in a state of being attached to an external frame (hereinafter, simply referred to as a frame) 830, and are fixed code readers that read codes of the workpieces W conveyed by the conveying device B. The operation time of the fixed code readers 1A, 1B, 1C, and 1D is the time when operations for sequentially reading the codes of the workpieces W conveyed by the conveying device B are performed.

[0049] The frame 830 is a frame-shaped frame formed in a manner to surround the conveyor device B, and includes a lower member 831 arranged below the conveyor device B and extending in the width direction (X direction) of the conveyor device B, a pair of side members 832 extending upward (Z direction) from both sides of the lower member 831 in the longitudinal direction, and an upper member 833 extending in the width direction of the conveyor device B to connect the upper ends of the pair of side members 832. The frame 830 is fixed to the floor surface C ( Figure 2 shown) etc.

[0050] The housing 60 of the first code reader 1A for reading the code attached to the bottom surface of the workpiece W is attached to the lower member 831 via the bracket 810. Since the lower member 831 is located below the conveying surface of the conveying device B, the installation position of the first code reader 1A attached to the lower member 831 is located below the conveying surface of the conveying device B. The optical axis of the first code reader 1A attached to the lower member 831 faces upward, and the field of view of the first code reader 1A includes the gap between the upstream conveying mechanism B1 and the downstream conveying mechanism B2.

[0051] Since the gap between the upstream conveying mechanism B1 and the downstream conveying mechanism B2 is included in the field of view of the first code reader 1A, when the bottom surface of the workpiece W being conveyed passes through the gap between the upstream conveying mechanism B1 and the downstream conveying mechanism B2, the camera unit 3 ( Figure 3 The bottom surface is photographed by a first barcode reader 1A (shown in FIG. 1 ). The code may be attached to the bottom surface of the workpiece W. In the case where the code is attached to the bottom surface of the workpiece W, since the first barcode reader 1A is installed at a mounting position below the conveying surface of the conveying device B, the code attached to the bottom surface of the workpiece W can be read from below the conveying surface of the conveying device B through the gap between the upstream conveying mechanism B1 and the downstream conveying mechanism B2.

[0052] Similar to the first code reader 1A, the second code reader 1B for reading a code attached to one side of the workpiece W is attached to one side member 832 via a bracket (not illustrated). The optical axis of the second code reader 1B attached to one side member 832 is set to face one side of the workpiece W.

[0053] Similar to the first code reader 1A, the housing 60 of the third code reader 1C for reading the code attached to the other side of the workpiece W is attached to the other side member 832 via the bracket 810. The optical axis of the third code reader 1C attached to the other side member 832 is set to face the other side of the workpiece W.

[0054] Similar to the first code reader 1A, the housing 60 of the fourth code reader 1D for reading a code attached to the upper surface of the workpiece W is attached to the upper member 833 via the bracket 810. The optical axis of the fourth code reader 1D attached to the upper member 833 faces downward.

[0055] The structure of the frame 830 is an example, and may not be a frame-shaped frame. For example, the frame may be any one of a frame including only the lower member 831, a frame including only the side member 832, and a frame including only the upper member 833. In addition, the frame may include any two of the lower member 831, the side member 832, and the upper member 833. In addition, the code reader may not be attached to all of the lower members 831, the side members 832, and the upper member 833, and the code reader may be attached to any one of the lower member 831, the side member 832, and the upper member 833, or any two or more of them. In addition, the frame may be fixed to the conveying device B, other members, equipment, etc., for example. In addition, the shape of the frame may be straight, or may be curved or bent.

[0056] The code attached to the workpiece W includes both a barcode and a two-dimensional code. Examples of two-dimensional codes include QR code (registered trademark), micro QR code and data matrix (data code), Veri code, Aztec code, PDF417, Maxi code, etc. Two-dimensional codes include stacked type and matrix type, but the present invention can be applied to any two-dimensional code. The code can be attached by printing or embossing the code directly on the workpiece W, or the code can be attached by attaching the code to the workpiece W after printing the code on a label, and the manner and method thereof are not limited.

[0057] like Figure 1As shown, the first to fourth code readers 1A, 1B, 1C and 1D are connected to a computer 200 and a programmable logic controller (PLC) 201 by wiring via signal lines 200a and 201a, respectively. However, the present invention is not limited thereto. A wireless communication module may be incorporated into the first to fourth code readers 1A, 1B, 1C and 1D, the computer 200 and the PLC 201, and the first to fourth code readers 1A, 1B, 1C and 1D may be wirelessly connected to the computer 200 and the PLC 201. The PLC 201 is a control device that sequentially controls the conveying device B and the first to fourth code readers 1A, 1B, 1C and 1D, and a general-purpose PLC can be used. As the computer 200, a general-purpose or dedicated electronic computer, a portable terminal, etc. may be used.

[0058] In addition, the first to fourth code readers 1A, 1B, 1C, and 1D receive a read start trigger signal for defining the start timing of code reading from the PLC 201 via the signal line 201a when operating. Then, the first to fourth code readers 1A, 1B, 1C, and 1D perform code imaging and decoding processing based on the read start trigger signal. Thereafter, the decoding result of the decoding processing is transmitted to the PLC 201 via the signal line 201a. As described above, in the operation of the first to fourth code readers 1A, 1B, 1C, and 1D, the input of the read start trigger signal and the output of the decoding result are repeated between the first to fourth code readers 1A, 1B, 1C, and 1D and an external control device such as the PLC 201 via the signal line 201a. Note that the input of the read start trigger signal and the output of the decoding result may be performed via the signal line 201a between the first to fourth code readers 1A, 1B, 1C, and 1D and the PLC 201 as described above, or may be performed via other signal lines (not illustrated). For example, a sensor for detecting the arrival of the workpiece W may be directly connected to the first to fourth code readers 1A, 1B, 1C, and 1D, and the read start trigger signal may be input from the sensor to the first to fourth code readers 1A, 1B, 1C, and 1D.

[0059] The first to fourth code readers 1A, 1B, 1C and 1D are the same. Figure 3 The first code reader 1A is described in detail. The first code reader 1A includes an illumination unit 2, an imaging unit 3, a control unit 4, a storage unit 5, a communication unit 6, a plane mirror 33, and a housing 60. The illumination unit 2, the imaging unit 3, the control unit 4, the storage unit 5, the communication unit 6, and the plane mirror 33 are accommodated in the housing 60.

[0060] The control unit 4 includes an image capture control unit 41 that controls the image capture unit 3, an illumination control unit 42 that controls the illumination unit 2, a code detection unit 43, and a decoding unit 44. In addition, the storage unit 5 can be composed of a readable / writable storage device such as a solid state drive (SSD). The storage unit 5 can store, for example, various programs, decoding results, image data, setting information, etc., and includes a decoding result storage unit 51, an image data storage unit 52, and a setting storage unit 53. Although not shown in the figure, the decoding result storage unit 51, the image data storage unit 52, and the setting storage unit 53 can be set in different storage devices.

[0061] The communication unit 6 performs communication with the computer 200 and the PLC 201. The setting information using the computer 200 is received by the control unit 4 via the communication unit 6. In addition, the control unit 4 receives a read start trigger signal from the PLC 201 via the communication unit 6. Information related to the decoding result of the first code reader 1A is sent to the computer 200 or the PLC 201 via the communication unit 6. In addition, the communication unit 6 receives, for example, the size of the gap formed between the plurality of conveying mechanisms B1 and B2 of the conveying device B, the conveying speed of the conveying device B, etc. The user can input the size of the gap and the conveying speed in advance to the computer 200, etc. The inputted size of the gap and the conveying speed are stored in the computer 200, and after being sent from the computer 200, the size of the gap and the conveying speed are received and acquired by the communication unit 6.

[0062] The lighting unit 2 is a portion that irradiates the workpiece W with illumination light. When the first code reader 1A is attached to the lower member 831 of the frame 830, the illumination range of the illumination light of the lighting unit 2 includes the gap between the upstream conveying mechanism B1 and the downstream conveying mechanism B2. In this case, since the first code reader 1A is installed below the conveying surface of the conveying device B, the lighting unit 2 emits illumination light from below the conveying surface toward the gap. Thus, when the bottom surface of the workpiece W being conveyed passes through the gap between the upstream conveying mechanism B1 and the downstream conveying mechanism B2, the bottom surface can be illuminated by the lighting unit 2. When a code is attached to the bottom surface of the workpiece W, the code attached to the bottom surface of the workpiece W can be illuminated by the lighting unit 2.

[0063] Although not a necessary configuration, the illumination unit 2 includes a first illumination unit 2a and a second illumination unit 2b. The first illumination unit 2a and the second illumination unit 2b illuminate the Scheimpflug optical system 31 described later with illumination light ( Figure 4The first illumination section 2a and the second illumination section 2b include a light emitting section including, for example, a light emitting diode (LED) or the like. The illumination section 2 may include a single illumination section without including the first illumination section 2a and the second illumination section 2b. Note that the Scheimpflug optical system 31 is not necessarily included, and the present invention can also be applied to a case where the Scheimpflug optical system 31 is not included.

[0064] The lighting unit 2 and the camera unit 3 may be integrated, or the lighting unit 2 and the camera unit 3 may be separated. The lighting unit 2 is turned on, off, changes the brightness when lit, etc. by the control of the lighting control unit 42. When a read start trigger signal is input from the PLC 201, the lighting control unit 42 lights the lighting unit 2 for a predetermined time, and turns off the lighting unit 2 after the predetermined time has passed.

[0065] The camera unit 3 is a part that captures an image of the workpiece W through the gap between the upstream conveying mechanism B1 and the downstream conveying mechanism B2, generates a code image including a code, and outputs the code image to the control unit 4. In addition, the camera unit 3 of the second to fourth code readers 1B to 1D is a part that captures an image of the workpiece W from above the conveying surface of the conveying mechanism B, generates a code image including a code, and outputs the code image to the control unit 4. The camera unit 3 includes a Scheimpflug optical system 31 and a preprocessing circuit 32. Figure 4 As shown, the Scheimpflug optical system 31 includes a lens 31a and an image sensor 31b having a two-dimensional light receiving surface inclined relative to the optical axis 10 of the lens 31a. The lens 31a is an imaging lens that collects reflected light from the bottom surface of the workpiece W. The light incident on the lens 31a is emitted toward the light receiving surface of the image sensor 31b and forms an image on the light receiving surface, thereby projecting an image corresponding to the code attached to the workpiece W on the light receiving surface of the image sensor 31b.

[0066] In this example, since the Scheimpflug optical system 31 is provided, the focal plane 7 is formed to extend in the V direction of the image sensor 31 b , and the focal plane 7 is inclined in the V direction of the image sensor 31 b .

[0067] The image sensor 31b includes a light receiving element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS), which converts the image of the code obtained by the lens 31a into an electrical signal. Based on the amount of light received by the light receiving surface of the image sensor 31b, an image including the code is generated. The image sensor 31b includes a plurality of imaging elements arranged in the row direction and the column direction, and the image sensor 31b is configured so that the row direction is roughly consistent with the direction from the near side to the far side of the focal plane of the Scheimpflug optical system 31. The aspect ratio of the image sensor 31b is set to be smaller than the aspect ratio of the light receiving window 622 described later. Then, the image sensor 31b is configured to be able to partially output a signal from an imaging element corresponding to the light receiving window 622 among the plurality of imaging elements.

[0068] That is, if a line sensor is used as an image sensor, high-speed reading can be performed, but there is a risk that the frame rate becomes extremely high for reading the code and the heating value of the illumination unit 2 increases. In this regard, in the present embodiment, an area sensor in which a plurality of imaging elements are arranged in the row direction and the column direction is used as the image sensor 31b, and only a portion (partial row) corresponding to the light receiving window 622 is partially read, so that both heat suppression and high-speed reading can be achieved.

[0069] The image generated by the image sensor 31b is input to the pre-processing circuit 32. The pre-processing circuit 32 can be provided as needed and is not essential.

[0070] The preprocessing circuit 32 includes, for example, an integrated circuit such as a field programmable gate array (FPGA), and is a part that performs various preprocessing on the image output from the image sensor 31b. The preprocessing includes, for example, various filtering. The imaging unit 3 outputs the image preprocessed by the preprocessing circuit 32 to the control unit 4. It is also possible to perform preprocessing using the preprocessing circuit 32 as needed, and output the image without preprocessing to the control unit 4. The image output to the control unit 4 is stored in the image data storage unit 52 included in the storage unit 5.

[0071] The camera unit 3 is controlled by the camera control unit 41. When a read start trigger signal is input from the PLC 201, the camera control unit 41 generates an image by performing exposure for a preset exposure time. The camera control unit 41 also controls the camera unit 3 to perform a process of applying a preset gain to the image generated by the image sensor 31b as needed and amplifying the brightness of the image through digital image processing. In addition, the camera control unit 41 determines the frame rate (the number of shots per second) of the camera unit 3 based on the size of the gap between the conveying mechanisms B1 and B2 (the width of the gap) and the conveying speed received by the communication unit 6. For example, the camera control unit 41 increases the frame rate of the camera unit 3 as the conveying speed increases. For example, the frame rate can be set in the range of 500fps to 5000fps. As the frame rate increases, in order to obtain sufficient brightness within a short exposure time, stronger light is required, so that the calorific value of the lighting unit 2 also increases proportionally. Since the second to fourth code readers 1B to 1D do not capture images through the gap between the conveying mechanisms B1 and B2, it is not necessary to determine the frame rate based on the size of the gap between the conveying mechanisms B1 and B2.

[0072] like Figures 5 to 7 As shown, the first code reader 1A includes a housing 60 that accommodates the lighting unit 2, the camera unit 3, and the control unit 4. The housing 60 may accommodate the camera unit 3 and the control unit 4, and may not accommodate the lighting unit 2. In this case, the lighting unit 2 is a lighting unit that is configured separately from the housing 60 that accommodates the camera unit 3 and the control unit 4, but is synchronously controlled by the control unit 4 when capturing an image of the workpiece W. The lighting unit that is configured separately from the housing 60 is also called an external lighting unit.

[0073] The housing 60 has an elongated shape along a predetermined direction (first direction). Figure 2 As shown, the first code reader 1A and the fourth code reader 1D are installed so that the first direction is the horizontal direction (X direction). On the other hand, the second code reader 1B and the third code reader 1C are installed so that the first direction is the up-down direction (Z direction). As described above, the installation postures of the code readers 1A, 1B, 1C, and 1D can be set according to the structure of the conveying device B, which surface of the workpiece W is to be read, etc., and are not limited to the illustrated postures, and may be, for example, a posture inclined relative to the X direction or a posture inclined relative to the Z direction.

[0074] The housing 60 has a first side surface 61, a second side surface 62, a third side surface 63 and a fourth side surface 64, and also has a first end surface 65 and a second end surface 66. In this embodiment, as Figures 5 to 7As shown in the figure, the depth direction (front-back direction), left-right direction and up-down direction of the housing 60 are defined, but this definition is for the convenience of description and does not limit the actual use posture of the first code reader 1A. In fact, there may be a situation where the up-down direction is reversed, or the up-down direction is installed horizontally, and the directions described below can be replaced in consideration of the actual installation posture. Figures 5 to 7 In the case shown, the first direction is the left-right direction. Therefore, the size of the housing 60 in the left-right direction is longer than the size of the housing 60 in the up-down direction and the depth direction. In addition, the number of sides of the housing 60 is not limited to six, and may be a shape having six or more sides.

[0075] According to the above definition, the first side surface 61 is a surface (front) located at the front side of the shell 60, and has a shape that is elongated in the left-right direction. The second side surface 62 is a side surface adjacent to the first side surface 61, extending from the upper edge (one edge) of the first side surface 61 toward the back side, and also extending in the left-right direction, and is a surface (upper side) located at the upper side of the shell 60. The third side surface 63 is a side surface adjacent to the first side surface 61, extending from the lower edge (other edge) of the first side surface 61 toward the back side, and also extending in the left-right direction, and is a surface (lower side) located at the lower side of the shell 60. The fourth side surface 64 is a side surface located at a position opposite to the first side surface 61, extending from the edge on the back side of the second side surface 62 to the edge on the back side of the third side surface in the up-down direction, and also extending in the left-right direction, and is a surface (rear side) located at the rear side of the shell 60. The first side surface 61 and the fourth side surface 64 are substantially parallel to each other. In addition, the second side surface 62 and the third side surface 63 are substantially parallel to each other.

[0076] The first end surface 65 is the left end surface of the housing 60 and extends in the depth direction and the up-down direction. The second end surface 66 is the right end surface of the housing 60 and extends in the depth direction and the up-down direction. The first end surface 65 and the second end surface 66 are substantially parallel to each other.

[0077] The housing 60 includes a box-shaped housing 600 constituting a part of the housing 60 and a cover-shaped housing 610 constituting another part of the housing 60, and the box-shaped housing 600 and the cover-shaped housing 610 integrally form the housing 60. The cover-shaped housing 610 is a first housing constituent member, and the box-shaped housing 600 is a second housing constituent member.

[0078] The box-shaped housing 600 is a member constituting the first side 61, the second side 62, the fourth side 64, the first end face 65, and the second end face 66, and is made of a resin obtained by molding a resin material. The box-shaped housing 600 is a member constituting a portion other than the third side 63, and therefore has a shape in which the third side 63 is open. The cover-shaped housing 610 is a member constituting the third side 63, and is made of metal. Examples of the metal material constituting the cover-shaped housing 610 include metal materials with high heat transfer coefficients such as aluminum alloys. Therefore, the cover-shaped housing 610 is superior to the box-shaped housing 600 in terms of heat dissipation. On the other hand, the resin material constituting the box-shaped housing 600 is inferior to the metal material constituting the cover-shaped housing 610 in terms of heat dissipation, but has a low specific gravity. Therefore, the weight of the box-shaped housing 600 can be reduced.

[0079] The cover-like housing 610 is attached to the box-like housing 600 to cover an open portion of the box-like housing 600 . Figure 8 The box-shaped housing 600 is removed, and as shown in the figure, a main package 611 made of an elastic material such as rubber, thermoplastic elastomer, etc. is arranged on the joint surface 610a of the cover-shaped housing 610 with the box-shaped housing 600. The main package 611 is formed in an annular shape along the peripheral edge of the cover-shaped housing 610, and as shown in the figure, Fig. 9 As shown, the cover 610 is held in a state of being accommodated in a groove 600a formed in the box-shaped housing 600. Since the groove 600a of the box-shaped housing 600 is a portion for accommodating the annular main package 611, the groove has an annular shape similar to the main package 611 and is open to the cover-shaped housing 610 side. In addition, although not illustrated, a groove for accommodating the main package 611 may be formed in the cover-shaped housing 610.

[0080] In the state where the cover-shaped housing 610 is integrated with the box-shaped housing 600, the main package 611 accommodated in the groove 600a is in close contact with the joint surface 610a of the cover-shaped housing 610. As a result, the space between the box-shaped housing 600 and the cover-shaped housing 610 is sealed by the main package 611, and external water and the like do not enter the interior of the housing 60.

[0081] like Figure 5 and Figure 6As shown, a light-transmitting member 620 that transmits light such as reflected light from the workpiece W and illumination light emitted from the illumination unit 2 is provided on the first side surface 61 of the box-shaped housing 600. The light-transmitting member 620 is a member that constitutes a light-projecting window 621 that transmits the illumination light emitted from the illumination unit 2 to the outside of the housing 60 and a light-receiving window 622 that transmits the reflected light from the workpiece W to the inside of the housing 60. Since the light-projecting window 621 and the light-receiving window 622 are formed by the common light-transmitting member 620, the number of components can be reduced. In addition, since the first side surface 61 is one side surface of the housing 60, the housing 60 is a member having the light-projecting window 621 and the light-receiving window 622 on this side.

[0082] The light-transmitting member 620 forms a plane extending in the left-right direction and the up-down direction of the housing 60. The plane formed by the light-transmitting member 620 may also be defined as a virtual plane including the front (or back) of the light-transmitting member 620. Note that the light-transmitting member 620 may not be a perfect plane, and may be a surface curved to be optically flat.

[0083] The light transmitting member 620 has an elongated shape along the longitudinal direction of the housing 60. The light transmitting member 620 is not particularly limited but is made of, for example, acrylic, glass, polycarbonate, etc. Note that the light projecting window 621 and the light receiving window 622 may be configured as separate members.

[0084] like Figure 5 As shown, a window frame member 630 for fixing the light transmitting member 620 to the first side 61 of the box-shaped housing 600 is provided on the first side 61 of the box-shaped housing 600. The window frame member 630 has a rectangular shape long in the left-right direction to correspond to the outer shape of the light transmitting member 620.

[0085] On the joint surface (not shown) between the window frame member 630 and the box-shaped housing 600, a window frame package 631 ( Figure 8 ). The window frame package 631 is formed annularly along the peripheral edge of the window frame member 630, and as shown Fig.10 As shown, the window frame member 630 is held in a state of being accommodated in a groove 630a formed in the window frame member 630. Since the groove 630a of the window frame member 630 is a portion for accommodating the annular window frame package 631, the groove has an annular shape similar to the window frame package 631 and is open toward the box-shaped housing 600 side. In addition, although not illustrated, a groove for accommodating the window frame package 631 may be formed in the box-shaped housing 600.

[0086] The window frame package 631 accommodated in the groove 630a is in close contact with the outside of the light-transmitting member 620 in a state where the window frame member 630 is integrated with the box-shaped housing 600. As a result, the space between the light-transmitting member 620 and the window frame member 630 is sealed by the window frame package 631, and external water or the like does not enter the interior of the housing 60 from the window frame member 630.

[0087] The first lighting section 2a is accommodated on the right side of the center portion in the left-right direction of the housing 60. The second lighting section 2b is accommodated on the left side of the center portion in the left-right direction of the housing 60. That is, the lighting section 2 includes the first lighting section 2a and the second lighting section 2b that are arranged apart from each other in the longitudinal direction of the housing 60.

[0088] like Fig.11 As shown, the first lighting unit 2a includes a light-emitting substrate 2i equipped with a plurality of LEDs, a wide-angle lighting lens 2j, and a narrow-angle lighting lens 2k. The light-emitting substrate 2i extends in the left-right direction and the up-down direction. A plurality of LEDs are arranged in a matrix in front of the light-emitting substrate 2i at intervals in the left-right direction and the up-down direction. The wide-angle lighting lens 2j and the narrow-angle lighting lens 2k are attached to the common light-emitting substrate 2i. The plurality of wide-angle lighting lenses 2j and the plurality of narrow-angle lighting lenses 2k are integrally formed in a manner protruding in the optical axis direction and are formed by one member.

[0089] The wide-angle illumination lens 2j is arranged in a manner corresponding to the plurality of LEDs mounted on the right side of the light-emitting substrate 2i, and forms a wide angle so as to be able to illuminate a wide range with light from the LED. The wide-angle illumination lens 2j and the LED corresponding to the wide-angle illumination lens 2j constitute a first illumination angle illumination unit in which the extension of the illumination light is a first illumination angle.

[0090] The narrow-angle lighting lens 2k is arranged in a manner corresponding to the plurality of LEDs mounted on the left side of the light-emitting substrate 2i, and is formed to have a narrow angle so that the illumination light can be emitted to a narrower range compared to the wide-angle lighting lens 2j. The narrow-angle lighting lens 2k and the LED corresponding to the narrow-angle lighting lens 2k constitute a second illumination angle illumination unit that extends the illumination light to have a second illumination angle wider than the first illumination angle. Then, the wide-angle lighting lens 2j and the LED corresponding to the wide-angle lighting lens 2j, and the narrow-angle lighting lens 2k and the LED corresponding to the narrow-angle lighting lens 2k are arranged in the longitudinal direction of the housing 60.

[0091] The dimension of the narrow-angle illumination lens 2k in the optical axis direction is set to be longer than the dimension of the wide-angle illumination lens 2j in the optical axis direction. In addition, the dimension in the radial direction at the base of the narrow-angle illumination lens 2k is set to be shorter than the dimension in the radial direction at the base of the wide-angle illumination lens 2j. The second illumination portion 2b is symmetrical to the first illumination portion 2a on both sides. That is, in the longitudinal direction of the housing 60, the narrow-angle illumination lens 2k is arranged on the outside (away from the position of the camera unit 3 located in the center), and the wide-angle illumination lens 2j is arranged on the inside. As a result, the illumination distribution of the housing 60 in the longitudinal direction is made more uniform.

[0092] Since the first lighting unit 2a is accommodated on the right side of the housing 60, the first lighting unit 2a and the light receiving window 622 are arranged side by side along the first direction to form an irradiation surface (a surface of the light projection window 621) that irradiates the workpiece W with illumination light. In addition, since the second lighting unit 2b is accommodated on the left side of the housing 60, the second lighting unit 2b is also arranged side by side with the light receiving window 622 along the first direction to form an irradiation surface (a surface of the light projection window 621) that irradiates the workpiece W with illumination light.

[0093] like Figure 8 As shown, a first light shielding member 67 for forming a first light projection chamber R1 in which the first lighting unit 2a is accommodated and a second light shielding member 68 for forming a second light projection chamber R2 in which the second lighting unit 2b is accommodated are provided in the housing 60. The first light shielding member 67 is made of, for example, a resin material having a light shielding property, is accommodated on the right side in the housing 60, and is formed to surround the first lighting unit 2a. The second light shielding member 68 is made of a material similar to that of the first light shielding member 67, is accommodated on the left side in the housing 60, and is formed to surround the second lighting unit 2b.

[0094] Since the illumination light emitted from the first illumination section 2a is blocked by the first light shielding member 67, it is possible to suppress the illumination light from being incident on the lens 31a of the imaging unit 3. In addition, since the illumination light emitted from the second illumination section 2b is blocked by the second light shielding member 68, it is possible to suppress the illumination light from being incident on the lens 31a of the imaging unit 3.

[0095] The housing 60 includes a light receiving chamber R3 formed by a portion other than the first light projection chamber R1 and the second light projection chamber R2 in the housing 60. That is, since the light receiving chamber R3 is formed by the outer space of the first light shielding member 67 and the second light shielding member 68 in the housing 60, the light receiving chamber R3 is a chamber optically isolated from the lighting units 2a and 2b.

[0096] In the light receiving chamber R3, the image pickup unit 3 and the plane mirror 33 are accommodated. The image pickup unit 3 is arranged on the back side of the second lighting section 2b in the housing 60. The image sensor 31b is installed in the housing 60 in the longitudinal direction of the housing 60 as the first direction. In this embodiment, since the image sensor 31b is accommodated on the left side of the housing 60, the light receiving surface of the image sensor 31b faces the right. Note that the image pickup unit 3 may be arranged on the back side of the first lighting section 2a in the housing 60. In this case, the image sensor 31b may be arranged so that the light receiving surface faces the left.

[0097] Since the light receiving surface of the image sensor 31b faces the right side, the optical axis of the lens 31a points to the left and right directions, the side where light enters the lens 31a is the right side, and the side where light leaves the lens 31a is the left side. The lens 31a is also arranged on the back side of the second lighting unit 2b and is located on the right side of the image sensor 31b.

[0098] The plane mirror 33 is a component for turning back the optical path corresponding to the field of view of the imaging unit 3 in the direction of the light receiving window 622 in the housing 60. Specifically, the plane mirror 33 is arranged between the first lighting unit 2a and the second lighting unit 2b. The plane mirror 33 extends in the up-down direction and is inclined relative to the longitudinal direction of the housing 60 in such a manner that it is positioned more to the right as it moves toward the front side. The inclined arrangement of the plane mirror 33 enables the optical path corresponding to the field of view of the imaging unit 3 to be turned back in the direction of the light receiving window 622. In the present embodiment, the reflected light reflected from the workpiece W passes through the light receiving window 622 and then enters the plane mirror 33. The light incident on the plane mirror 33 is configured to be emitted toward the lens 31a of the imaging unit 3.

[0099] like Figure 6 and Figure 7 As shown, the housing 60 is provided with a polarization filter attachment 652 to cover the light-transmitting member 620. The polarization filter attachment 652 is attachable and detachable relative to the housing 60 and can be used as needed. Figure 5 A state in which the polarization filter attachment 652 is removed is illustrated.

[0100] The polarization filter attachment 652 is provided with a polarization filter 652a having a polarization film or the like so as to face the light-transmitting member 620. Between the polarization filter 652a and the light-transmitting member 620, a light-shielding material 652b is provided for suppressing the illumination light emitted from the first illumination section 2a and the second illumination section 2b from entering the optical system 31 of the imaging unit 3.

[0101] like Figure 5 and Figure 8As shown, the housing 60 is arranged to face the outside of the housing 60, forms a part of the light receiving chamber R3, and includes an indicator 69 that emits light based on the processing result of the decoding unit 44. The indicator 69 is controlled by the control unit 4, and emits light of a first color in the case where the decoding result of the decoding unit 44 is obtained normally, and emits light of a second color different from the first color in the case where an error occurs. Since the indicator 69 forms a part of the light receiving chamber R3, the light of the part of the indicator 69 can enter the light receiving chamber R3. On the other hand, in the present embodiment, at least during the exposure of the image pickup unit 3, the control unit 4 performs extinguishing control to extinguish the indicator 69. For example, by extinguishing the indicator 69 from the start to the end of the exposure of the image pickup unit 3, it is possible to prevent the light of the indicator 69 from affecting the image generated by the image pickup unit 3.

[0102] A plurality of heat sinks 640 extending in the left-right direction are provided on the third side surface 63 of the cover-shaped housing 610. Since the longitudinal direction of the light-transmitting member 620 is the left-right direction, the longitudinal direction of the heat sink 640 coincides with the longitudinal direction of the light-transmitting member 620. The plurality of heat sinks 640 are formed at intervals in the depth direction (width direction) of the housing 60. The heat sink 640 is made of the same material as the material of the portion constituting the second side surface 62, and thus has a high heat transfer coefficient.

[0103] like Figure 7 As shown, the housing 60 is provided with a covering portion 650 covering the front end portions of the plurality of heat sinks 640. Since the covering portion 650 covers the front end portions of the plurality of heat sinks 640, an air passage extending in the longitudinal direction of the light-transmitting member 620 is formed by the third side surface 63 of the housing 60, the spaces between the plurality of heat sinks 640, and the covering portion 650.

[0104] The first code reader 1A includes a fan 70 that blows air in the longitudinal direction of the heat sink 640. The heat sink 640 is located in a portion where air is forcedly blown by the fan 70.

[0105] The heat sink 640 is discontinuous in the longitudinal direction of the heat sink 640. Specifically, the cutout portion 640a is formed by cutting out the middle portion in the longitudinal direction of the heat sink 640. As a result, since the heat sink 640 is intermittently provided in the left-right direction, for example, even if the air passage is closed due to the end portions of the heat sink 640 in the left-right direction being in close contact with any member, the air blown into the air passage can escape from the cutout portion 640a to the outside, and a decrease in cooling efficiency can be suppressed.

[0106] like Fig.12 and Fig.13As shown, a through hole 612 that penetrates the cover-like housing 610 in the inner and outer directions is provided in the portion of the cover-like housing 610 where the fan 70 is arranged. A portion of the fan 70 attached to the cover-like housing 610 protrudes into the housing 60 while being accommodated in the through hole 612. Thus, while a large-diameter fan 70 can be used, the amount of downward protrusion of the fan 70 can be reduced, and as a result, the size of the first code reader 1A in the upper and lower directions can be shortened.

[0107] In addition, if Fig.12 As shown, the control board 90 provided with the control unit 4 is attached to the cover-like housing 610 via an attachment member 91. The attachment member 91 is, for example, a member having heat conductivity similar to the cover-like housing 610. Since the control unit 4 is a portion that performs a decoding process of a code attached to the workpiece W based on an image generated by the image sensor 31b, the temperature rises during operation. By inserting the attachment member 91, the heat of the control board 90 can escape to the cover-like housing 610 and be released by the heat sink 640.

[0108] Figures 14 to 16 The lens holder 300 that holds the lens 31a of the image pickup unit 3 is exemplified, and the lens holder 300 has a fixing portion 300a fixed to the cover-shaped housing 610 and has a pitch adjustment mechanism for the image sensor 31b. Specifically, as shown in FIG. Fig.14 The sensor substrate 301 shown in FIG. Fig.15 The sensor holder 302 shown is attached to the lens holder 300. The sensor substrate 301 is a member to which the image sensor 31b is fixed.

[0109] like Fig.16 As shown, in a state where the sensor holder 302 is removed, three springs 303 provided inside the lens holder 300 can be seen. The three springs (helical springs) 303 are arranged in a manner to surround the extension line of the optical axis of the lens 31a. The plate-shaped sensor holder 302 is arranged in a manner overlapping the springs 303. The adjustment screws 304 are inserted into the portion of the sensor holder 302 corresponding to the springs 303. Each adjustment screw 304 is screwed into the lens holder 300 in a state of being inserted into the spring 303. The angle of the sensor holder 302 can be changed by tightening or loosening each adjustment screw 304. Since the image sensor 31b is fixed to the sensor holder 302 via the sensor substrate 301, the relative angle (i.e., the pitch angle) between the image sensor 31b and the lens 31a can be adjusted by changing the angle of the sensor holder 302. After the adjustment, the components are bonded to the lens holder 300 with an adhesive in a manner that does not move relative to each other.

[0110] In such Figure 1 and Figure 2 In the case where the first code reader 1A is installed as shown, the bottom surface of the workpiece W conveyed by the conveying device B is exposed to the first code reader 1A side from the gap between the upstream conveying mechanism B1 and the downstream conveying mechanism B2. The depth of field of the camera unit 3 of the first code reader 1A includes the bottom surface of the workpiece W exposed from the gap of the conveying device B. Thus, the camera unit 3 can directly photograph the bottom surface of the workpiece W through the gap between the upstream conveying mechanism B1 and the downstream conveying mechanism B2. The so-called "directly" means that the camera unit 3 photographs the bottom surface of the workpiece W without inserting a reflective member such as a mirror.

[0111] In such Figure 1 and Figure 2 When the image sensor 31b is installed as shown, the light receiving window 622 is aligned with the gap of the conveying device B. In this state, the row direction of the image sensor 31b corresponds to the direction in which the gap of the conveying device B extends, and the column direction of the image sensor 31b corresponds to the conveying direction of the conveying device B ( Figure 1 corresponds to the direction indicated by the arrow A in the figure.

[0112] Therefore, if Fig.17 As shown, the imaging unit 3 outputs a plurality of images capturing a portion of a code attached to the bottom surface of the workpiece W by continuously capturing the bottom surface of the workpiece W exposed from the gap of the conveyor B and included in the depth of field of the imaging unit 3 . Fig.17 The upper side of the figure shows the upstream conveying mechanism B1 and the downstream conveying mechanism B2 conveying the workpiece W as viewed from below, and the workpiece W is conveyed from left to right as shown in the figure. Since the size of the code in the conveying direction is longer than the gap between the upstream conveying mechanism B1 and the downstream conveying mechanism B2, only a part of the code in the conveying direction is exposed downward from the gap between the upstream conveying mechanism B1 and the downstream conveying mechanism B2. Fig.17 As shown in the lower part of FIG. 1 , a plurality of images capturing a portion of the code in the conveying direction are sequentially output from the imaging unit 3. The plurality of images output from the imaging unit 3 are input to the control unit 4.

[0113] The control unit 4 is a unit that generates a composite image based on a plurality of images output from the imaging unit 3 and performs a decoding process on the code attached to the bottom surface of the workpiece W based on the composite image. Figure 2 As shown, as a specific configuration example of the control unit 4, for example, a configuration example including a microcomputer having a processor (including a central processing unit), ROM, RAM, etc. can be exemplified. The imaging control unit 41, the illumination control unit 42, the code detection unit 43, and the decoding unit (decoder) 44 are configured by hardware included in the control unit 4, software executed by the control unit 4, etc.

[0114] The code detection unit 43 of the control unit 4 is a unit that specifies a code area based on the code image output from the camera unit 3 and detects a code from the specified code area. The decoding unit 44 of the control unit 4 is a unit that decodes the code detected by the code detection unit 43, and specifically, since the code is represented by black and white binary data, the decoding unit decodes the black and white binary data. For decoding, a table indicating the contrast relationship of the encoded data can be used. In addition, the decoding unit 44 checks whether the decoding result is correct according to a predetermined inspection method. In the case where an error is found in the data, an error correction function is used to calculate the correct data. The error correction function varies depending on the type of code. Below, the details of the code detection unit 43 and the decoding unit 44 of the first code reader 1A are specifically described, but this also applies to the second to fourth code readers 1B, 1C, 1D.

[0115] Below, reference Fig.18 The flowchart shown in the figure explains the details of the processing of the control unit 4. This flowchart starts when the operation of the first code reader 1A for the bottom surface starts. In step SA1 after the start, a read start trigger signal is input from the PLC 201 to the first code reader 1A. When the read start trigger signal is input, the lighting control unit 42 turns on the lighting unit 2, and the imaging control unit 41 causes the imaging unit 3 to capture an image to generate an image.

[0116] In step SA2, the code detection unit 43 performs geometric correction as needed. For example, in the case where the first code reader 1A is installed on the side of the conveying device B, and in the installation state where the geometric change occurs according to the installation angle of the first code reader 1A, each image has a trapezoidal diameter. In this case, in step SA2, trapezoidal correction is performed on the trapezoidal shape of each image. Thereby, an image similar to an image in the case of taking a picture from directly below the workpiece W can be obtained.

[0117] In step SA3, the code detection unit 43 combines the multiple processed images that have been geometrically corrected in step SA2 to generate a combined image including the code. In step SA4, it is determined whether the number of times the camera unit 3 captures images has reached a specified number of times. The number of times is set to the number of times that the entire code can be captured. In the case of a negative determination in step SA4, the process proceeds to step SA1, and the image capture, geometric correction, and image synthesis are repeated until the entire code is captured. In the case of a positive determination in step SA4, the process proceeds to step SA5.

[0118] In step SA5, the code detection unit 43 generates a plurality of edge images by applying a plurality of edge extraction filters that extract edges of different frequencies to the images combined in step SA3, and then performs integration processing of the plurality of edge images. The code detection unit 43 determines the code candidate position based on the result of the edge integration processing. That is, in the edge-processed image, an area where many pixels with large brightness values ​​are gathered can be estimated as a code area.

[0119] For example, in order to search for the position of the code in the code image, the code detection unit 43 can generate a heat map image indicating the similarity of the code. That is, the code detection unit 43 quantifies the characteristic amount of the code, generates a heat map that assigns the size of the characteristic amount to each pixel value, and extracts the code candidate area where the code may exist on the heat map. As a specific example, there is a method for obtaining the characteristic part of the code in the area that is relatively hot (having a large characteristic amount) in the heat map. In the case of obtaining multiple characteristic parts, the characteristic parts can be preferentially extracted and stored in RAM, etc. By using the heat map image, the code area can be detected at high speed. The decoding unit 44 decodes the code searched by the code detection unit 43.

[0120] like Figure 3 , Figure 6 and Figure 8 As shown in FIG. 1 , the first code reader 1A includes a communication interface 80 for transmitting information related to the result of the decoding process of the decoding unit 44. The communication interface 80 is, for example, a portion that connects the signal lines 200a and 201a, etc., and is provided at an end portion in the longitudinal direction of the housing 60. In this embodiment, the communication interface 80 is provided on the side where the imaging unit 3 is arranged (i.e., the first end surface 65).

[0121] The connection direction of the signal lines 200a and 201a to the communication interface 80 is a direction along the longitudinal direction of the housing 60. Thus, the signal lines 200a and 201a do not protrude from the side surfaces 61 to 64 of the housing 60.

[0122] The first code reader 1A includes a bracket 810 as an attachment portion for attaching the housing 60 to the frame 830. The bracket 810 is provided on a side of the housing 60 different from the light receiving window 622 (i.e., the third side 63). The side on which the light receiving window 622 is provided is the first side 61, and the first side 61 and the third side 63 are adjacent to each other. That is, among the first side 61 to the fourth side 64 constituting the outer surface of the housing 60, the first side 61 (first side) including the light receiving window 622 and the irradiation surface 621 and the third side 63 (second side) on which the bracket 810 is provided are adjacent to each other.

[0123] The bracket 810 includes a housing side member 811 fixed to the housing 60, a frame side member 812 fixed to the frame 830, and a connecting shaft 813 rotatably connecting the housing side member 811 and the frame side member 812. By rotating the housing side member 811 relative to the frame side member 812, the installation angle of the housing 60 can be freely adjusted, and the housing 60 can be freely adjusted. Fig.19 The angle shown changes to Fig. 20 The housing side member 811 and the frame side member 812 can be fixed by a fastening member or the like so as not to rotate relative to each other.

[0124] A guide surface 60a used as a guide during installation is formed in the housing 60. The guide surface 60a is formed by chamfering a portion of the housing 60. For example, when the angle between the reading surface and the optical axis of the camera unit 3 is 60°, the angle of the guide surface 60a is set so that the guide surface 60a and the reading surface have a parallel relationship. In addition, when the angle between the reading surface and the optical axis of the camera unit 3 is 60°, the surface (reference surface) of the housing side member 811 on the reading surface side is formed to have a parallel relationship with the reading surface, and the distance between the reading surface and the reference surface can be regarded as the installation distance of the code reader 1A (particularly the camera unit 3).

[0125] Here, in order to respond to various needs and uses from users, it is assumed that a plurality of types of code readers (i.e., optical systems) with different reading distances are developed. In the case of attaching the bracket 810 (housing side member 811) to the code reader 1, as long as the reference surface of the bracket 810 and the camera unit 3 of the code reader 1 are designed to have approximately the same positional relationship, regardless of the type of the code reader 1, the user is only required to measure the installation distance based on the common reference surface of the bracket 810. Therefore, the user's attachment is simplified, and there is no need to provide a separate bracket 810 for each type of code reader 1.

[0126] Fig.21 The case 60 is shown as viewed from the front. As shown in the figure, the bracket 810 is provided with a pressing portion 814 for pressing the signal line 201a. By providing the pressing portion 814, the signal line 201a can be positioned at a predetermined position. The pressing portion 814 includes, for example, a convex portion.

[0127] Fig. 22811 is a bottom view of a housing side member 811 fixed to the housing 60. The housing side member 811 is formed with an attachment hole 815 for attaching to the housing 60, and by using the attachment hole 815, the housing side member 811 can be fixed to the housing 60 using a screw (not shown). In addition, the housing side member 811 is provided with a field of view center mark 816 for indicating the field of view center. By viewing the field of view center mark 816 at the time of installation and aligning the field of view center mark with the frame side member 812, the field of view center can be easily grasped.

[0128] Fig.23 1 is a side view illustrating an example of attachment in which the optical axis of the image pickup unit 3 is perpendicular to the reference plane. As shown in the figure, the mounting angle of the housing 60 can be adjusted so that the optical axis of the image pickup unit 3 is perpendicular to the reference plane. Fig.24 An installation example in the case of using a mirror is illustrated, and the housing 60 may also be installed so that the mirror 880 is interposed between the imaging unit 3 and the workpiece W. When the mirror 880 is inserted, the reflected light from the code is reflected by the mirror 880 and enters the imaging unit 3. In addition, the illumination light emitted from the illumination section 2 is reflected by the mirror 880 and reaches the workpiece W to which the code is attached. Inserting the mirror 880 improves the degree of freedom when installing the housing 60.

[0129] Fig.25 An example of mounting in the case where the attachment surface of the bracket 810 is changed is illustrated. Fig.25 The left side of the example illustrates a case where the bracket 810 is attached to the third side surface 63 of the housing 60, and Fig.25 The right side of FIG. 1 illustrates a case where the bracket 810 is attached to the fourth side 64 of the housing 60. Fig.25 As shown, by attaching the bracket 810 to the third side 63 of the housing 60, the height of the frame 830 relative to the reference plane becomes the first height H1, and can be lower than the case of attaching to the fourth side 64 (the second height H2). Figure 1 and Figure 2 In the code readers 1A to 1D shown, the protrusion amount of the code readers 1A to 1D from the respective members 831 to 833 of the frame 830 toward the conveying device B side is reduced, so that the degree of freedom in installation can be improved.

[0130] (Other embodiments)

[0131] Embodiments of the present invention are not limited to the above-described embodiments, and may be, for example, other embodiments described below. In the following description of other embodiments, the same components as those in the above-described embodiments are represented by the same reference numerals, descriptions thereof are omitted, and different parts are described in detail. In addition, by combining the above-described embodiments with the following other embodiments, other embodiments may also be formed. When combining the above-described embodiments with the following other embodiments, the position of the above-described embodiments and a part of the following other embodiments may be combined.

[0132] Fig.26 The first example shown is an example in which the camera unit 30 of the fourth code reader 1D includes a first camera unit 30a and a second camera unit 30b. The first to third code readers 1A, 1B, and 1C can be configured similarly. The first camera unit 30a and the second camera unit 30b are accommodated in a state of being divided into left and right. The first camera unit 30a is accommodated on the left side of the housing 60, and the second camera unit 30b is accommodated on the right side of the housing 60. A first mirror 881 and a second mirror 882 are accommodated in the center of the housing 60 in the left-right direction. The first mirror 881 is a member for allowing the reflected light from the code to enter the first camera unit 30a. The second mirror 882 is a member for allowing the reflected light from the code to enter the second camera unit 30b.

[0133] The first camera unit 30a includes a first image sensor 30c and a first optical system 30d. The first image sensor 30c has a two-dimensional light-receiving surface for forming a predetermined field of view, and is a component that generates an image corresponding to an image projected onto the light-receiving surface via the light-receiving window 622. The first optical system 30d is a component that is interposed between the light-receiving window 622 and the light-receiving surface of the first image sensor 30c, and projects an image corresponding to a code mounted to the workpiece W onto the light-receiving surface of the first image sensor 30c in the housing 60. The first optical system 30d is long along the longitudinal direction of the light-receiving window 622, and forms an optical path whose optical axis passing through the center of the field of view is inclined relative to the longitudinal direction. The field of view and depth of the first camera unit 30a can be set by various parameters of the first optical system 30d.

[0134] The second camera unit 30b includes a second image sensor 30e and a second optical system 30f. The second image sensor 30e has a two-dimensional light-receiving surface for forming a predetermined field of view, and is a component that generates an image corresponding to the image projected onto the light-receiving surface via the light-receiving window 622. The second optical system 30f is a component that is interposed between the light-receiving window 622 and the light-receiving surface of the second image sensor 30e, and projects an image corresponding to the code mounted to the workpiece W onto the light-receiving surface of the second image sensor 30e in the housing 60. The second optical system 30f is long along the longitudinal direction of the light-receiving window 622, and forms an optical path in which the optical axis passing through the center of the field of view is inclined relative to the longitudinal direction. The field of view and depth of the second camera unit 30b can be set by various parameters of the second optical system 30f. The optical axis of the first camera unit 30a and the optical axis of the second camera unit 30b have a close relationship.

[0135] The field of view and depth of the first camera unit 30a are different from the field of view and depth of the second camera unit 30b. Specifically, the field of view and depth of the first camera unit 30a are determined by Fig. 27 The range surrounded by the dotted frame shown by the reference numeral 8A in the figure (referred to as the first range). Various parameters of the first optical system 30d are set to be within the first range 8A. On the other hand, the field of view and depth of the second camera unit 30b are within the range defined by Fig. 27 The range surrounded by the solid-line frame shown by the reference numeral 8B in FIG. 8 (referred to as a second range). Various parameters of the second optical system 30f are set to be within the second range 8B.

[0136] The first range 8A is set to include an area farther than the second range 8B, and the farthest field of view A1 of the first range 8A extends from the farthest field of view A2 of the second range 8B. The second range 8B is set to include an area closer than the first range 8A. By setting the first image sensor 30c and the second image sensor 30e, the field of view and depth of the camera unit 30 are expanded. In short, the camera unit 30 includes the first image sensor 30c and the second image sensor 30e to expand the field of view and depth in the depth direction orthogonal to the plane forming the light receiving window 622 in the camera field of view. Note that in addition to the first camera unit 30a and the second camera unit 30b, a third camera unit can also be set. In this case, the fields of view and depths of the first camera unit 30a, the second camera unit 30b and the third camera unit can be configured to be different from each other.

[0137] Since the first camera unit 30a is a camera unit capable of photographing a farther side than the second camera unit 30b, it can be referred to as a telephoto camera unit. On the other hand, since the second camera unit 30b is a camera unit capable of photographing a near side of the first camera unit 30a, it can be referred to as a close-up camera unit. As described above, the camera unit 30 includes a close-up camera unit for photographing a near side and a telephoto camera unit for photographing a far side. In the case where a third camera unit is provided, the third camera unit can be, for example, a close-up camera unit.

[0138] The first code reader 1A further includes a light amount reducing member 30g ( Fig.26 As shown, the light reducing component 30g reduces the light difference between the light incident on the first image sensor 30c of the first camera unit 30a as the far-side camera unit and the light incident on the second image sensor 30e of the second camera unit 30b as the near-side camera unit. Thus, since the brightness difference of the images obtained by each camera unit is suppressed, parameter switching caused by the difference in brightness value is not required in the subsequent image processing, and the processing load can be reduced. The light reducing component 30g includes a light reduction filter (for example, an ND filter) provided in the second optical system 30f of the second camera unit 30b. The light reduction amount of the light reduction filter can be arbitrarily set. The light reducing component 30g can be set as needed and can be omitted.

[0139] Fig.28A second example is shown which is the same as the first example in that the imaging unit 30 includes the first imaging unit 30a and the second imaging unit 30b, but is different from the first example in the field of view and depth of the first image sensor 30c and the second image sensor 30e. In addition, compared with the first example, the optical axis of the first imaging unit 30a and the optical axis of the second imaging unit 30b are separated from each other. That is, in the second example, the first range 8A is set to be located below the second range 8B and includes an area farther than the second range 8B. The field of view and depth of the imaging unit 30 extend from the farthest field of view range A1 of the first range 8A and the farthest field of view range A2 of the second range 8B. In the second example, since the optical path of the first imaging unit 30a and the optical path of the second imaging unit 30b are inconsistent, a partial area of ​​the light receiving window 622 is a portion corresponding to the optical path of the first imaging unit 30a, and the other area is a portion corresponding to the optical path of the second imaging unit 30b. In this case, the light amount reducing member 30g may include a dimming filter provided in a portion of the light receiving window 622 corresponding to the optical path of the second imaging unit 30b. This can reduce the difference in light quantity between the light quantity incident on the second image sensor 30e of the second imaging unit 30b and the light quantity incident on the first image sensor 30c of the first imaging unit 30a. In the second example, similarly to the first example, a light reduction filter may be provided in the second optical system 30f.

[0140] Fig.29 30a and 30b are accommodated on the left side of the housing 60. In the third example, a mirror 883 is accommodated in the center of the housing 60 in the left-right direction. The mirror 883 is a member for allowing the reflected light from the code to enter the first camera unit 30a and the second camera unit 30b. In addition, in this example, by providing the first camera unit 30a and the second camera unit 30b, the field of view and the depth can be expanded as described above. Note that the first camera unit 30a and the second camera unit 30b can be accommodated on the right side of the housing 60.

[0141] Fig.30 6 is a diagram illustrating a fourth example in which the first and second imaging units 30a and 30b are housed in the left-right center of the housing 60. In the fourth example, reflected light from the code passes through the light receiving window 622 and then enters the first and second imaging units 30a and 30b.

[0142] Fig.313 is a diagram illustrating a case where a zoom lens capable of focus adjustment is used as the lens 31a of the image pickup unit 3. By using a variable focus lens, the depth of the image pickup unit 3 can be changed in multiple stages. In this example, the depth of the image pickup unit 3 is changed in three stages, in which the first range 8A focuses on the far side, the second range 8B focuses on the near side, and the third range 8C focuses on the intermediate distance. As a result, the field of view and the depth can be expanded without increasing the number of image pickup units 3. Note that the depth of the image pickup unit 3 can be changed in 2 stages, or in 4 or more stages. The variable focus lens includes, for example, a mechanically movable lens and a liquid lens.

[0143] The multiple other embodiments described above may be independent of each other, but any multiple other embodiments among the multiple other embodiments may be combined with each other.

[0144] The present invention is not limited to the code reader. For example, a part of the present invention can also be applied to a case where a control unit configured not to perform code decoding processing is provided. In this case, the image processing device is an image processing device that processes an image acquired by photographing an image of the workpiece W conveyed by the conveying device B, and the control unit is a part that performs various types of image processing. Examples of various types of image processing include OCR processing and image inspection processing.

[0145] The above embodiments are merely examples in all aspects and should not be interpreted in a limiting manner. In addition, all modifications and changes that fall within the equivalent scope of the claims are within the scope of the present invention.

[0146] As described above, the code reader according to the present disclosure can be used in the case of, for example, reading a code attached to a workpiece.

Claims

1. A fixed code reader configured to be used in a state of being attached to an external frame and to read a code attached to a workpiece conveyed by a conveying device, the code reader comprising: a housing having a long side extending in a first direction and having a light receiving window for transmitting light transversely intersecting the first direction; an illumination unit, which is accommodated in the housing and forms an illumination surface arranged side by side with the light receiving window along the first direction, the illumination surface being used to illuminate the workpiece with illumination light; an imaging unit including an image sensor having a two-dimensional light-receiving surface and mounted in the housing toward the first direction, and a lens for projecting an image corresponding to a code attached to the workpiece on the light-receiving surface of the image sensor in the housing; a mirror, for folding the light path corresponding to the field of view of the camera unit in the housing in the direction of the light receiving window; a decoder for performing a decoding process of a code attached to a workpiece based on the image generated by the imaging unit; as well as An attachment portion is provided on a side of the housing different from a side of the light receiving window and is configured to attach the housing to the outer frame.

2. The code reader according to claim 1, further comprising: A communication interface is provided at an end of the housing in the first direction and is configured to transmit information related to a result of a decoding process by the decoder.

3. The code reader according to claim 1, wherein: Among the plurality of side surfaces constituting the outer surface of the housing, a first side surface including the light receiving window and the irradiated surface and a second side surface provided with the attachment portion are adjacent to each other.

4. The code reader according to claim 1, wherein: The light receiving surface is inclined relative to the optical axis of the lens, and The lens and the image sensor constitute a Sham optical system.

5. The code reader according to claim 1, wherein: The imaging unit includes the lens or the plurality of image sensors for expanding the field of view or depth in a depth direction orthogonal to a plane forming the light receiving window in the field of view.

6. The code reader according to claim 1, wherein: The camera unit includes a near camera unit for photographing a near side and a far camera unit for photographing a far side, and The code reader further includes a light amount reducing member configured to reduce a light amount difference from an amount of light incident on the image sensor of the telephoto imaging unit by reducing an amount of light incident on the image sensor of the close imaging unit.

7. The code reader according to claim 6, wherein: The light amount reducing member includes a light reduction filter provided in an optical system of the close-up imaging unit.

8. The code reader according to claim 6, wherein: The light amount reducing member includes a light reduction filter provided in a portion of the light receiving window corresponding to an optical path of the close-up imaging unit.

9. The code reader according to claim 1, wherein: The lighting section includes a first lighting section and a second lighting section that are spaced apart from each other in the first direction.

10. The code reader according to claim 9, wherein: The mirror is arranged between the first lighting section and the second lighting section.

11. The code reader according to claim 10, wherein: The imaging unit is disposed on the back side of the first lighting section or the back side of the second lighting section in the housing.

12. The code reader according to claim 1, wherein: The lighting section includes a first illumination angle lighting section and a second illumination angle lighting section, in which the expansion of the illumination light has a first illumination angle, and in which the expansion of the illumination light has a second illumination angle wider than the first illumination angle, and the first illumination angle lighting section and the second illumination angle lighting section are arranged in the first direction.

13. The code reader according to claim 1, wherein: A light projection window configured to transmit illumination light emitted from the illumination unit to the outside of the housing and the light receiving window are formed by a common light-transmitting member.

14. The code reader according to claim 13, wherein: The light-transmitting member is formed to have a long side extending in the first direction, and The code reader also includes: a window frame member for fixing the light-transmitting member to the housing; and A packaging member is interposed between the window frame member and the light-transmitting member.

15. The code reader according to claim 1, wherein: A light shielding member for preventing illumination light emitted from the illumination section from entering the lens of the image pickup unit is provided inside the housing.

16. The code reader according to claim 1, wherein: At least a portion of the housing is formed by a first housing-constituting member made of metal and having fins extending in a predetermined direction, A control board provided with the decoder is attached to the first case constituting member via a member having a heat transfer property.

17. The code reader according to claim 16, wherein: The heat sink extends along the first direction, and The code reader further includes a fan configured to blow air in a longitudinal direction of the heat sink.

18. The code reader according to claim 16, wherein: A portion of the housing is formed by the first housing component, Another part of the housing is formed by a second housing constituent member made of resin, and The first housing component and the second housing component are integral.

19. The code reader according to claim 1, wherein: The housing comprises: a light receiving chamber for accommodating the imaging unit and the mirror and isolated from the lighting unit, and an indicator for forming a part of the light receiving chamber and emitting light based on the processing result of the decoder, The code reader further comprises a control unit for controlling the camera unit, the decoder and the indicator, and The control unit performs light-off control to light off the indicator at least during exposure of the imaging unit.

20. A fixed image processing device configured to be usable in a state of being attached to an external frame and to process an image acquired by photographing an image of a workpiece conveyed by a conveying device, the image processing device comprising: a housing having a long side extending in a first direction and having a light receiving window for transmitting light transversely intersecting the first direction; an illumination unit, which is accommodated in the housing and forms an illumination surface arranged side by side with the light receiving window along the first direction, the illumination surface being used to illuminate the workpiece with illumination light; an imaging unit, comprising an image sensor and a lens, wherein the image sensor has a two-dimensional light-receiving surface and is mounted in the housing toward the first direction, and wherein the lens projects an image corresponding to the workpiece onto the light-receiving surface of the image sensor in the housing; a mirror, for folding the light path corresponding to the field of view of the camera unit in the housing in the direction of the light receiving window; a control unit, configured to perform image processing based on the image generated by the camera unit; as well as An attachment portion is provided at one side of the housing and is configured to attach the housing to the external frame.

Images