Travel distance calculation device

Abstract

A movement distance calculation device is provided that can improve the accuracy in acquiring optical information about the surface of a workpiece compared to conventional devices. [Solution] A movement distance calculation device (1, 2, 3, 4, 5, 6) includes a light source (10) that irradiates light onto a workpiece moving in a movement direction, an optical system (20) that guides the light from the workpiece irradiated by the light source (10) along an optical axis (L2) that intersects with both the movement direction and an orthogonal direction that is perpendicular to the surface of the workpiece extending along the movement direction, an optical sensor (30, 130) that acquires optical information of the surface of the workpiece based on the light from the optical system (20), and a movement distance calculation unit (103) that calculates movement distance information regarding the movement distance of the workpiece during the period from the first time to the second time based on a correlation value that indicates the correlation between first optical information acquired by the optical sensor (30, 130) at a first time and second optical information acquired by the optical sensor (30, 130) at a second time.

Description

[Technical Field]

[0001] The present disclosure relates to a travel distance calculation device. [Background technology]

[0002] Conventionally, a displacement meter has been disclosed that measures the displacement (movement distance) of a measurement object (workpiece) transported by a transport device based on one-dimensional information (optical information) from a line sensor that detects reflected light from the surface of the measurement object (workpiece) (see, for example, Patent Document 1). This displacement meter detects the extremum of the cross-correlation function of multiple images detected at different times by the line sensor, and calculates the amount of displacement of the measurement object based on the detection results. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-170550 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, when an optical sensor is used to acquire optical information of the surface of a workpiece extending along the direction of movement of the workpiece, the position of the workpiece surface may change in a direction perpendicular to the surface of the workpiece due to workpiece vibration, individual differences in the workpiece, errors in the position of the workpiece, etc. In such cases, the optical information acquired by the optical sensor becomes blurred due to changes in the optical system that guides light from the surface of the workpiece to the optical sensor and the distance between the optical sensor and the surface of the workpiece, posing a problem that it is difficult to improve the accuracy in calculating the movement distance (amount of displacement) or movement speed of the workpiece.

[0005] The present disclosure was made in response to the recognition of the above-mentioned problem, and aims to provide a movement distance calculation device that can improve the accuracy of calculating information related to the movement distance of a workpiece compared to conventional devices. [Means for solving the problem]

[0006] The movement distance calculation device according to the present disclosure is characterized by comprising a light source that irradiates light onto a workpiece moving in a movement direction; an optical system that guides light from the workpiece irradiated by the light source along an optical axis that intersects both the movement direction and an orthogonal direction that is perpendicular to the surface of the workpiece extending along the movement direction; an optical sensor that acquires optical information of the surface based on the light from the optical system; and a movement distance calculation unit that calculates movement distance information regarding the movement distance of the workpiece during a period from the first time to the second time based on a correlation value that indicates the correlation between first optical information acquired by the optical sensor at a first time and second optical information acquired by the optical sensor at a second time. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to improve the accuracy in calculating information regarding the movement distance of a workpiece compared to the prior art. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing a schematic configuration of a travel distance calculation device according to a first embodiment. [Figure 2] 1 is a block diagram showing a schematic configuration of a travel distance calculation device according to a first embodiment. [Figure 3] 1 is a block diagram showing an example of a hardware configuration of an information processing device according to a first embodiment. [Figure 4] 1 is a block diagram showing an example of a hardware configuration of an information processing device according to a first embodiment. [Figure 5] 4 is a flowchart showing an example of processing performed by the information processing device according to the first embodiment. [Figure 6] FIG. 10 is a schematic diagram showing a schematic configuration of a travel distance calculation device according to a second embodiment. [Figure 7] FIG. 11 is a schematic diagram showing a schematic configuration of a travel distance calculation device according to a third embodiment. [Figure 8]FIG. 10 is a schematic diagram showing a schematic configuration of a travel distance calculation device according to a fourth embodiment. [Figure 9] FIG. 10 is a schematic diagram showing a schematic configuration of a travel distance calculation device according to a fifth embodiment. [Figure 10] FIG. 13 is a schematic diagram showing a schematic configuration of a travel distance calculation device according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Embodiment 1 First, with reference to FIG. 1, the configuration of a travel distance calculation device 1 according to the first embodiment will be described. FIG. 1 is a schematic diagram illustrating the overall configuration of the travel distance calculation device 1 according to the first embodiment. The travel distance calculation device 1 according to the first embodiment is, for example, a device for measuring the travel distance of a workpiece S0 based on changes in optical information of the surface of the moving workpiece S0. As shown in FIG. 1, the travel distance calculation device 1 includes a light source 10, an optical system 20, an optical sensor 30, and an information processing device 100. Note that in FIG. 1, the right direction is the X direction, the upward direction is the Z direction, and the direction from the back to the front is the Y direction. For example, the workpiece S0 is formed in a sheet shape extending in the X and Y directions. The workpiece S0 moves in the movement direction along the Y direction as the roll rotates while being unwound from a rolled-up state or while being wound up into a roll. Note that in the first embodiment, the upper surface of the workpiece shown in FIG. 1 is referred to as the surface of the workpiece. Note that in the first embodiment, the workpiece is not limited to being formed in a sheet shape, and may be formed in a plate-like, rod-like, block-like, or other shape.

[0010] The light source 10 irradiates light onto the workpiece S0 moving in the movement direction. For example, the light source 10 irradiates light onto a specific portion of the workpiece S0 extending in the movement direction. Specifically, the light source 10 irradiates light onto the surface of the workpiece S0 extending in the movement direction. For example, the light source 10 is configured as a laser light source that irradiates laser light toward the surface of the workpiece S0 along an optical axis L1. Specifically, the light source 10 has multiple light-emitting elements (not shown) arranged along a direction intersecting the XZ plane, and irradiates light onto a specific portion of the surface of the workpiece S0.

[0011] More specifically, the light source 10 has a plurality of light-emitting elements arranged along the Y direction, and emits sheet-like laser light from each of the plurality of light-emitting elements toward the surface of the workpiece S0 along an optical axis L1 that is parallel to the XZ plane, perpendicular to the Y direction, and intersects with both the X and Z directions. For example, the light source 10 has a plurality of light-emitting elements arranged along the Y direction, and emits sheet-like laser light from each of the plurality of light-emitting elements toward the surface of the workpiece S0 along an optical axis L1 that is parallel to the XZ plane, perpendicular to the Y direction, and intersects with both the X and Z directions at 45°. As a result, the optical system 20 is positioned relative to the light source 10 and the workpiece S0 at a position where light from the light source 10 is directly reflected (specularly reflected) from the surface of the workpiece S0.

[0012] The optical system 20 guides light from the workpiece S0 irradiated with light by the light source 10 along an optical axis L2 that intersects with both the Z direction and the Y direction. In other words, the optical system 20 guides light from the workpiece S0 irradiated with light by the light source 10 along the optical axis L2 that intersects with both the direction of movement of the workpiece S0 and an orthogonal direction that is perpendicular to the surface of the workpiece S0 and extends along the direction of movement of the workpiece S0. For example, the optical system 20 has multiple lenses including a first lens 21 and a second lens 22 that are arranged with a gap between them along the optical axis L2, and forms an image of the light from the workpiece S0 irradiated with light by the light source 10 on the light receiving surface of the optical sensor 30.

[0013] Furthermore, for example, the optical system 20 is disposed so that the optical axis L2 is perpendicular to the optical axis L1 of the light source 10 when viewed in the Y direction. Specifically, the optical system 20 is disposed so that the optical axis L2 is perpendicular to the optical axis L1 of the light source 10 when viewed in the Y direction and is also perpendicular to the Y direction. For example, if the light source 10 is disposed so as to irradiate the surface of the workpiece S0 with light along the optical axis L1 that is parallel to the XZ plane, perpendicular to the Y direction, and intersects each of the X direction and the Z direction at 45°, the optical system 20 is disposed so that the optical axis L2 is parallel to the XZ plane, perpendicular to the Y direction, and intersects each of the X direction and the Z direction at 45°.

[0014] The optical sensor 30 acquires optical information of the surface of the workpiece S0 based on the light from the optical system 20. For example, the optical sensor 30 captures an image of the surface of the workpiece S0 based on the light from the optical system 20 and acquires image information of the surface of the workpiece S0 as optical information. For example, the optical sensor 30 has a light receiving element (not shown) that converts the received light into an electrical signal, and acquires the optical information of the surface of the workpiece S0 by the light receiving element. Specifically, the optical sensor 30 has a light receiving element such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

[0015] Furthermore, for example, the optical sensor 30 is arranged at different positions in the movement direction of the workpiece S0 and has a plurality of light-receiving elements that receive light from the optical system 20. Specifically, the optical sensor 30 is configured as a two-dimensional area sensor in which N image pickup elements numbered 1 to N (for example, N is a natural number equal to or greater than 2) are linearly arranged along a first direction perpendicular to the optical axis L2, and M image pickup elements numbered 1 to M (for example, M is a natural number equal to or greater than 2) are linearly arranged along a second direction perpendicular to the optical axis L2 and the first direction. In other words, the optical sensor 30 is configured as a two-dimensional area sensor that is arranged in a plane along a virtual plane perpendicular to the optical axis L2 of the optical system 20 and has a plurality of light-receiving elements that receive light from the optical system 20. The optical sensor 30 outputs the acquired optical information to the information processing device 100.

[0016] Next, an information processing device 100 according to the first embodiment will be described with reference to Fig. 2. Fig. 2 is a block diagram showing a schematic configuration of a travel distance calculation device according to the first embodiment. As shown in Fig. 2, the information processing device 100 includes an optical information acquisition unit 101, a correlation value calculation unit 102, a travel distance calculation unit 103, and a storage unit 104.

[0017] The optical information acquisition unit 101 acquires optical information of the workpiece S0 moving in the X direction based on information from the optical sensor 30. For example, the optical information acquisition unit 101 acquires image data of the workpiece S0 moving in the X direction based on information from the optical sensor 30.

[0018] The correlation value calculation unit 102 calculates a correlation value indicating the correlation between the two pieces of optical information acquired at two different times by the optical information acquisition unit 101. For example, the correlation value calculation unit 102 calculates, by phase-only correlation, a correlation value indicating the correlation between reference optical information as first optical information serving as a reference and acquired in advance at a first time by the optical information acquisition unit 101, and measured optical information as second optical information acquired at a second time different from the first time.

[0019] The movement distance calculation unit 103 calculates movement distance information regarding the movement distance of the work S0 in the X direction based on the correlation value calculated by the correlation value calculation unit 102. For example, the movement distance calculation unit 103 calculates the distance between two pieces of optical information acquired at two different times, at which the correlation value of the optical information is highest, based on the correlation value calculated by the correlation value calculation unit 102, thereby calculating the movement distance of the work S0 in the X direction between the two times. Note that the movement distance calculation unit 103 is not limited to calculating only the movement distance of the work S0 in the X direction as movement distance information, and may be configured to calculate movement distance information regarding the movement distance of the work based on the correlation value calculated by the correlation value calculation unit 102. For example, information indicating the movement speed of the work is obtained by differentiating the movement distance of the work by the movement time, and therefore can be said to be information regarding the movement distance. For this reason, the movement distance calculation unit 103 may calculate the movement distance of the work S0 in the X direction as the movement distance information, or may calculate the movement speed of the work S0 in the X direction based on the calculated movement distance, or may calculate the movement speed of the work S0 in the X direction without using the calculation result of the movement distance of the work S0 in the X direction.

[0020] The storage unit 104 stores information used when the information processing device 100 performs each process and information indicating the results of each process. The storage unit 104 stores, for example, the optical information acquired by the optical information acquisition unit 101, a function indicating the waveform of each piece of optical information calculated by the correlation value calculation unit 102, the results of processing by the movement distance calculation unit 103, various setting values ​​used when each component of the information processing device 100 performs a process, etc. When each component of the information processing device 100 performs a process, it refers to and reads the information stored in the storage unit 104 as necessary, and stores the results of each process in the storage unit 104.

[0021] Next, the hardware configuration of the information processing device 100 will be described with reference to FIGS. 3 and 4. FIG. 3 is a block diagram showing an example of the hardware configuration of the information processing device 100 according to the first embodiment, and FIG. 4 is a block diagram showing an example of a hardware configuration of the information processing device 100 according to the first embodiment, which is different from that shown in FIG. 3. For example, as shown in FIG. 3, the information processing device 100 includes a processor 100a, a memory 100b, and an I / O port 100c, and is configured so that the processor 100a reads and executes a program stored in the memory 100b. The memory 100b is configured, for example, by a non-volatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, or an EEPROM, or a combination thereof. The memory 100b may also be a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, a DVD, or the like. The memory 100b may also be an HDD or an SSD.

[0022] 4, the information processing device 100 includes a processing circuit 100d and an I / O port 100c, which are dedicated hardware. The processing circuit 100d is configured, for example, by a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a system LSI (Large-Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. Each function of the information processing device 100 is realized by the processor 100a or the processing circuit 100d, which is dedicated hardware, executing a program that is software, firmware, or a combination of software and firmware. The information processing device 100 may also include hardware other than those described above, such as a hardware timer.

[0023] Next, with reference to Fig. 2 and Fig. 5, an example of processing in which the information processing device 100 measures the movement distance of the workpiece S0 based on changes in optical information of the surface of the moving workpiece S0 acquired by the movement distance calculation device 1 will be described. Fig. 5 is a flowchart showing an example of processing performed by the information processing device according to the fifth embodiment. First, when the information processing device starts processing, it acquires reference optical information (step ST01). In this processing, the information processing device 100 acquires image information, which is optical information acquired by the optical sensor 30 at time t, as reference optical information, which is optical information that serves as a reference when the correlation value calculation unit 102 calculates a correlation value.

[0024] After performing the process of step ST01, the information processing device 100 acquires measured optical information (step ST02). In this process, when the correlation value calculation unit 102 calculates the correlation value, the information processing device 100 acquires image information, which is optical information acquired by the optical sensor 30 at time (t+Δt), which is a time Δt after time t, as measured optical information that is optical information to be compared with the reference optical information acquired in the process of step ST01.

[0025] After performing the processing of step ST02, the information processing device 100 calculates a correlation value between the reference optical information and the immediately preceding measured optical information (step ST03). In this processing, the information processing device 100 obtains the results of fast Fourier transforms of the image information, which is the reference optical information acquired at time t in the processing of step ST01, and the image information, which is the measured optical information acquired at time (t + Δt) in the processing of the immediately preceding step ST02, and calculates a correlation value between the image information acquired at time t and the image information acquired at time (t + Δt) by phase-only correlation. In other words, the information processing device 100 performs pattern matching between the image information acquired at time t and the image information acquired at time (t + Δt) by phase-only correlation.

[0026] After performing the process of step ST03, the information processing device 100 calculates the movement distance of the workpiece S0 in the X direction, which is the measurement direction (step ST04). In this process, the information processing device 100 detects a peak in the intensity of the received light based on the result of the phase-only correlation method, and calculates the movement distance of the workpiece S0 in the X direction at time Δt based on the movement distance of the peak in the intensity of the received light and the distance between the multiple light-receiving elements of the optical sensor 30.

[0027] After performing the process of step ST04, the information processing device 100 determines whether the number of times reaches the end number (step ST05). In this process, the information processing device 100 determines whether a sufficient number of samples for calculating the movement distance of the work S0 has been acquired.

[0028] In the processing of step ST05, if the termination count has not been reached (NO in step ST05), the information processing device 100 returns the processing to step ST02 and acquires measured optical information for calculating a new movement distance. In this way, the information processing device 100 is configured to improve the calculation accuracy of the movement distance of the workpiece S0 in the X direction, for example, by repeating the processing from step ST02 to step ST05 multiple times to perform linear regression. In addition, the information processing device 100 can calculate the movement speed of the workpiece S0 based on the calculation result of the movement distance or the result of linear regression.

[0029] In the process of step ST05, if the number of times reaches the termination number (YES in step ST05), the information processing device 100 terminates the process.

[0030] Generally, when an optical sensor is used to acquire optical information about the surface of a moving workpiece, the position of the workpiece may change in a direction perpendicular to the workpiece surface due to workpiece vibration, individual workpiece differences, workpiece position errors, etc. In particular, when a sheet-shaped workpiece is moved at high speed, the position of the workpiece surface is likely to change in a direction perpendicular to the workpiece surface due to vibrations in a direction perpendicular to the workpiece surface. In such cases, the optical system that guides light from the workpiece surface to the optical sensor and the distance between the optical sensor and the workpiece surface change, blurring the optical information acquired by the optical sensor, making it difficult to improve the accuracy of acquiring optical information about the workpiece surface. For example, when an optical sensor is used to acquire image information as optical information about the workpiece surface, if the position of the workpiece surface changes in a direction perpendicular to the workpiece surface, the image becomes blurred, making the edges of the image unclear, making it difficult to improve the accuracy of the optical information.

[0031] In contrast, in the travel distance calculation device 1 according to the first embodiment, the optical system 20 is arranged so that the optical axis L2 of the optical system 20 is perpendicular to the optical axis L1 of the light source when viewed in the Y direction. This prevents the distance between the part of the workpiece irradiated with light by the light source 10 and the optical sensor 30 from changing, even if the position of the surface of the workpiece S0 changes between the workpiece S1 and the workpiece S2. In other words, the travel distance calculation device 1 prevents the optical path length from the surface of the workpiece to the optical sensor 30 from changing, even if the position of the surface of the workpiece S0 changes between the workpiece S1 and the workpiece S2. This makes it easier for light from the workpiece to be focused on the optical sensor 30, thereby improving the accuracy of acquiring optical information about the surface of the workpiece compared to conventional methods.

[0032] As described above, the travel distance calculation device 1 according to the first embodiment includes a light source 10 that irradiates light onto a workpiece moving in a travel direction, an optical system 20 that guides the light from the workpiece irradiated by the light source 10 along an optical axis L2 that intersects both the direction perpendicular to the surface of the workpiece extending along the travel direction and the travel direction, and an optical sensor 30 that acquires optical information of the surface of the workpiece based on the light from the optical system 20.

[0033] For example, in the travel distance calculation device 1 according to the first embodiment, the optical system 20 is arranged so that the optical axis L2 of the optical system 20 is perpendicular to the optical axis L1 of the light source 10 when viewed in the travel direction.

[0034] Configured in this manner, the movement distance calculation device 1 can suppress changes in the optical path length from the surface of the workpiece to the optical sensor 30 even if the position of the surface of the workpiece changes in a direction perpendicular to the surface of the workpiece.Therefore, by improving the accuracy in acquiring optical information about the surface of the workpiece compared to conventional methods, the accuracy in calculating information about the movement distance of the workpiece, such as the movement distance or movement speed, can be improved compared to conventional methods.

[0035] Furthermore, the travel distance calculation device 1 according to the first embodiment is configured so that specularly reflected light of light from the light source 10 on the surface of the workpiece S0 is incident on the optical system 20. With this configuration, the travel distance calculation device 1 can increase the amount of light received by the optical sensor 30 while suppressing the amount of light from the light source 10 and reducing power consumption, compared to a case where specularly reflected light of light from the light source 10 on the surface of the workpiece S0 is not incident on the optical system 20.

[0036] Moreover, the travel distance calculation device 1 according to the first embodiment is configured to irradiate light onto a specific portion of the workpiece extending in the movement direction, and to have a plurality of light receiving elements that are arranged in a plane along a virtual plane perpendicular to the optical axis L1 of the optical system 20 and receive light from the optical system 20. With this configuration, the travel distance calculation device 1 can be used to calculate information relating to the travel distance of the workpiece, for example, by performing pattern matching of optical information before and after the movement of the workpiece.

[0037] In the first embodiment, the travel distance calculation device 1 is configured so that light from the light source 10 is directly reflected on the surface of the workpiece S0 and enters the optical system 20, but is not limited to this. The travel distance calculation device may be configured so that light from the workpiece irradiated with light by the light source enters the optical system, and for example, the travel distance calculation device may be configured so that light from the light source is diffusely reflected on the surface of the workpiece S0 and enters the optical system.

[0038] Embodiment 2 Next, a travel distance calculation device 2 according to a second embodiment will be described with reference to Fig. 6. The travel distance calculation device 2 according to the second embodiment is an example of a travel distance calculation device configured so that light from a light source is diffusely reflected on the surface of a workpiece S0 and enters an optical system. The travel distance calculation device 2 according to the second embodiment differs from the travel distance calculation device 1 according to the first embodiment in the positions of the light source 10, the optical system 20, and the optical sensor 30 relative to the surface of the workpiece, but other features are similar, and the same components as those in the first embodiment are denoted by the same reference numerals and names, and description thereof will be omitted.

[0039] FIG. 6 is a schematic diagram showing a general configuration of a travel distance calculation device 2 according to a second embodiment. As shown in FIG. 6, the travel distance calculation device 2 includes a light source 10, an optical system 20, an optical sensor 30, and an information processing device 100. The light source 10 according to the second embodiment irradiates light onto the surface of the workpiece S0 moving in the movement direction. For example, the light source 10 according to the second embodiment is arranged so that light reflected directly from the surface of the workpiece S0 does not enter the optical system 20 by irradiating light onto the surface of the workpiece S0 along an optical axis L1 that is parallel to the XZ plane, perpendicular to the Y direction, and intersects with the X direction at an angle greater than 0° and less than 45°.

[0040] 6, when the range of positions on the surface of the workpiece S0 where the distance between the part of the workpiece irradiated with light by the light source 10 and the optical system 20 and optical sensor 30 does not change is between the workpieces S1 and S2, the light source 10 and the optical system 20 are arranged so that light from the light source 10 directly reflected along any of the optical axes L10 of light directly reflected by the surface of the workpiece S0, L11 of light directly reflected by the surface of the workpiece S1, and L12 of light directly reflected by the surface of the workpiece S2 does not enter the optical system 20. Note that in the travel distance calculation device 2 according to the second embodiment, the relative positions of the light source 10, the optical system 20, and the optical sensor 30 are the same as those in the travel distance calculation device 1 according to the first embodiment.

[0041] As described above, the travel distance calculation device 2 according to the second embodiment includes a light source 10 that irradiates light onto a workpiece moving in a movement direction, an optical system 20 that guides the light from the workpiece irradiated by the light source 10 along an optical axis L2 that intersects with both the movement direction and an orthogonal direction that is perpendicular to the surface of the workpiece extending along the movement direction, and an optical sensor 30 that acquires optical information about the surface of the workpiece based on the light from the optical system 20. For example, the travel distance calculation device 2 according to the second embodiment is configured so that specularly reflected light from the light source 10 on the surface of the workpiece S0 does not enter the optical system 20. Specifically, the travel distance calculation device 2 according to the second embodiment is configured to include a light source 10 that irradiates light onto the surface of the workpiece S0 along an optical axis L1 that intersects with the X direction at an angle greater than 0° and less than 45° when viewed in the Y direction.

[0042] With this configuration, when the workpiece S0 is made of a material that easily reflects light, the travel distance calculation device 2 can avoid a situation in which the light received by the optical sensor 30 is too strong, making it difficult for visual changes on the surface of the workpiece S0 to be reflected in the optical information acquired by the optical sensor 30. Furthermore, with this configuration, the travel distance calculation device 2 can reduce the distance in the X direction between the optical system 20 and the optical sensor 30, and can reduce the size of the device as a whole in the X direction, compared to a case in which the light source 10 is provided that irradiates light toward the surface of the workpiece S0 along the optical axis L1 that intersects with the Z direction at an angle greater than 0° and less than 45° when viewed in the Y direction.

[0043] Embodiment 3 Next, a travel distance calculation device 3 according to a third embodiment will be described with reference to Fig. 7. The travel distance calculation device 3 according to the third embodiment is an example of a travel distance calculation device different from that of the second embodiment, in that the light from the light source is diffusely reflected on the surface of the workpiece S0 and enters the optical system. The travel distance calculation device 3 according to the third embodiment differs from the travel distance calculation device 1 according to the first embodiment in the positions of the light source 10, the optical system 20, and the optical sensor 30 relative to the surface of the workpiece, but other features are the same. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals and names, and description thereof will be omitted.

[0044] FIG. 7 is a schematic diagram showing the overall configuration of a travel distance calculation device 3 according to a third embodiment. As shown in FIG. 7, the travel distance calculation device 3 includes a light source 10, an optical system 20, an optical sensor 30, and an information processing device 100. The light source 10 according to the third embodiment irradiates light onto the surface of the workpiece S0 moving in the movement direction. For example, the light source 10 according to the third embodiment is arranged so that the light is irradiated toward the surface of the workpiece S0 along an optical axis L1 that is parallel to the XZ plane, perpendicular to the Y direction, and intersects with the Z direction at an angle greater than 0° and less than 45°, thereby preventing direct reflection of light from the surface of the workpiece S0 from entering the optical system 20 and preventing diffuse reflection of light from the light source on the surface of the workpiece S0 from entering the optical system.

[0045] 7, when the range of positions on the surface of the workpiece S0 where the distance between the part of the workpiece irradiated with light by the light source 10 and the optical system 20 and optical sensor 30 does not change is between the workpieces S1 and S2, the light source 10 and the optical system 20 are arranged so that light from the light source 10 directly reflected along any of the optical axes L10 of light directly reflected by the surface of the workpiece S0, L11 of light directly reflected by the surface of the workpiece S1, and L12 of light directly reflected by the surface of the workpiece S2 does not enter the optical system 20. Note that in the travel distance calculation device 3 according to the third embodiment, the relative positions of the light source 10, the optical system 20, and the optical sensor 30 are the same as those in the travel distance calculation device 1 according to the first embodiment.

[0046] As described above, the travel distance calculation device 3 according to the third embodiment includes a light source 10 that irradiates light onto a workpiece moving in a movement direction, an optical system 20 that guides the light from the workpiece irradiated by the light source 10 along an optical axis L2 that intersects with both the movement direction and an orthogonal direction that is perpendicular to the surface of the workpiece extending along the movement direction, and an optical sensor 30 that acquires optical information about the surface of the workpiece based on the light from the optical system 20. For example, the travel distance calculation device 3 according to the third embodiment is configured so that specularly reflected light from the light source 10 on the surface of the workpiece S0 does not enter the optical system 20. Specifically, the travel distance calculation device 3 according to the third embodiment is configured to include a light source 10 that irradiates light onto the surface of the workpiece S0 along an optical axis L1 that intersects with the Z direction at an angle greater than 0° and less than 45° when viewed in the Y direction.

[0047] With this configuration, when the workpiece S0 is made of a material that easily reflects light, the travel distance calculation device 3 can avoid a situation in which the light received by the optical sensor 30 is too strong, making it difficult for visual changes on the surface of the workpiece S0 to be reflected in the optical information acquired by the optical sensor 30. Furthermore, with this configuration, the travel distance calculation device 3 can reduce the distance in the Z direction between the optical system 20 and the optical sensor 30, and can reduce the size of the device as a whole in the Z direction, compared to a case in which the light source 10 is provided that irradiates light toward the surface of the workpiece S0 along an optical axis L1 that intersects with the X direction at an angle greater than 0° and less than 45° when viewed in the Y direction.

[0048] In addition, in the embodiments 1-3, the travel distance calculation device includes an optical sensor 30 as an area sensor that is arranged in a plane along a virtual plane perpendicular to the optical axis L2 of the optical system 20 and has a plurality of light receiving elements that receive light from the optical system 20, but is not limited to this. The travel distance calculation device only needs to include an optical sensor that acquires optical information of the surface of the workpiece based on light from the optical system, and for example, the optical sensor may be configured with a single light receiving element, or may be configured with a one-dimensional line sensor in which N light receiving elements from number 1 to number N (for example, N is a natural number equal to or greater than 2) are linearly arranged.

[0049] Embodiment 4 Next, a travel distance calculation device 4 according to a fourth embodiment will be described with reference to Fig. 8. The travel distance calculation device 4 according to the fourth embodiment is an example of a travel distance calculation device equipped with an optical sensor configured with a one-dimensional line sensor. The travel distance calculation device 4 according to the fourth embodiment has different configurations of an optical system and an optical sensor compared to the travel distance calculation device 1 according to the first embodiment, but other configurations are the same. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals and names, and description thereof will be omitted.

[0050] 8 is a schematic diagram showing a schematic configuration of a travel distance calculation device 4 according to embodiment 4. As shown in FIG. 8, the travel distance calculation device 4 includes a light source 10, an optical system 120, an optical sensor 130, and an information processing device 100.

[0051] The optical system 120 guides light from the workpiece S0 irradiated with light by the light source 10 along an optical axis L2 that intersects with both the Z direction and the Y direction. In other words, the optical system 20 guides light from the workpiece S0 irradiated with light by the light source 10 along the optical axis L2 that intersects with both the direction perpendicular to the surface of the workpiece S0 that extends along the direction of movement of the workpiece S0 and the direction perpendicular to the surface of the workpiece S0. For example, the optical system 20 has a first lens 21, a second lens 22, and a third lens 23 that are arranged along the optical axis L2 with gaps between them.

[0052] The third lens 23 is disposed between the second lens 22 and the optical sensor 130, and is formed as a cylindrical lens that focuses light from the workpiece, which is incident via the first lens 21 and the second lens 22, in a straight line toward the light receiving surface of the optical sensor 130. Configured in this way, the optical system 120 forms an image of the light from the workpiece S0, which is irradiated with light by the light source 10, on the light receiving surface of the optical sensor 130.

[0053] The optical sensor 130 is arranged at different positions in the movement direction of the workpiece S0 and has a plurality of light receiving elements that receive light from the optical system 120. Specifically, the optical sensor 130 is configured as a one-dimensional line sensor in which N light receiving elements, numbered 1 to N (for example, N is a natural number equal to or greater than 2), are linearly arranged. In other words, the optical sensor 130 is configured as a one-dimensional line sensor that has a plurality of light receiving elements that are linearly arranged along the Y direction and receive light from the optical system 120. The optical sensor 130 outputs the acquired optical information to the information processing device 100.

[0054] The optical information acquiring unit 101 according to the fourth embodiment acquires optical information of the workpiece S0 moving in the X direction based on information from the optical sensor 30. For example, the optical information acquiring unit 101 according to the fourth embodiment acquires one-dimensional image data along the Y direction of the workpiece S0 moving in the X direction as optical information of the workpiece S0 based on information from the optical sensor 130. Note that the details of the correlation value calculating unit 102, the movement distance calculating unit 103, and the storage unit 104 according to the fourth embodiment are the same as those of the first embodiment, and therefore description thereof will be omitted.

[0055] As described above, the travel distance calculation device 4 according to the fourth embodiment includes a light source 10 that irradiates light onto a workpiece moving in the movement direction, an optical system 120 that guides the light from the workpiece irradiated with light by the light source 10 along an optical axis L2 that intersects with both the movement direction and an orthogonal direction that is perpendicular to the surface of the workpiece extending along the movement direction, and the movement direction, and an optical sensor 130 that acquires optical information of the surface of the workpiece based on the light from the optical system 120. For example, the travel distance calculation device 4 according to the fourth embodiment includes an optical sensor 130 that is arranged linearly along the movement direction and has a plurality of light receiving elements that receive light from the optical system 120, and an optical system 120 that has a cylindrical lens that linearly focuses light from the workpiece toward the plurality of light receiving elements.

[0056] Configured in this manner, the movement distance calculation device 4 is able to compress the amount of information compared to when optical information is acquired by an optical sensor configured as a two-dimensional line sensor, and it is possible to reduce the processing burden when processing using the optical information acquired by the optical sensor, for example, when calculating the movement distance of a workpiece.

[0057] In the first to fourth embodiments, the travel distance calculation device is configured such that the optical axis L2 of the optical system is perpendicular to the optical axis L1 of the light source, but is not limited to this. The travel distance calculation device may include an optical system that guides light from a workpiece irradiated with light by the light source along optical axes that intersect both the movement direction and an orthogonal direction that is perpendicular to the surface of the workpiece extending along the movement direction. For example, the travel distance calculation device may be configured such that the optical axis L2 of the optical system is perpendicular to the optical axis L1 of the light source when viewed in the Y direction, but that the optical axis L2 of the optical system is not actually perpendicular to the optical axis L1 of the light source, or may be configured such that the optical axis L2 of the optical system is not perpendicular to the optical axis L1 of the light source when viewed in the Y direction.

[0058] Embodiment 5. Next, a travel distance calculation device 5 according to a fifth embodiment will be described with reference to Fig. 9. The travel distance calculation device 5 according to the fifth embodiment is an example of a travel distance calculation device configured such that the optical axis L2 of the optical system is not perpendicular to the optical axis L1 of the light source. The travel distance calculation device 5 according to the fifth embodiment differs from the travel distance calculation device 1 according to the first embodiment in the arrangement of the light source, optical system, and optical sensor, but other features are similar. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals and names, and description thereof will be omitted.

[0059] FIG. 9 is a schematic diagram showing a general configuration of a travel distance calculation device 5 according to a fifth embodiment. As shown in FIG. 9, the travel distance calculation device 5 includes a light source 10, an optical system 20, an optical sensor 30, and an information processing device 100. In the fifth embodiment, the light source 10, the optical system 20, and the optical sensor 30 are arranged such that, when viewed in the Y direction, the optical axis L1 of the light source 10, the principal surface of the lens of the optical system 20 (or the principal surface of the combined lens if multiple lenses are included), and the light receiving surface of the optical sensor 30 intersect at one point, thereby satisfying the Scheimpflug principle. For example, the light source 10 is arranged such that the optical axis L1 is perpendicular to the surface of the workpiece S0 when viewed in the Y direction.

[0060] Configured in this manner, the travel distance calculation device 5 of embodiment 5 makes it easier for light incident on the optical system 20 to be focused on the optical sensor 30, even if the position of the surface of the workpiece S0 changes between the workpiece S1 and the workpiece S2, thereby improving the accuracy in obtaining optical information about the surface of the workpiece compared to conventional methods.

[0061] In the first to fifth embodiments, the travel distance calculation device includes a light source 10 that irradiates light onto the surface of the workpiece S0 extending in the movement direction, but is not limited to this. The travel distance calculation device may include a light source that irradiates light onto the workpiece moving in the movement direction, an optical system that guides the light from the workpiece irradiated by the light source along an optical axis that intersects with both the movement direction and the orthogonal direction perpendicular to the surface of the workpiece extending along the movement direction, and an optical sensor that acquires optical information of the surface based on the light from the optical system. For example, instead of including the light source 10 that irradiates light onto the surface of the workpiece S0 extending in the movement direction, the travel distance calculation device may include a light source 10 that irradiates light onto the back surface of the workpiece S0 extending in the movement direction of a sheet-shaped workpiece S0.

[0062] Embodiment 6 Next, a travel distance calculation device 6 according to a sixth embodiment will be described with reference to Fig. 10. The travel distance calculation device 6 according to the sixth embodiment is an example of a travel distance calculation device that is provided with a light source 10 that irradiates light onto the back surface of a workpiece S0 that extends in the movement direction, of a workpiece S0 that is formed in a sheet shape, instead of including a light source 10 that irradiates light onto the front surface of the workpiece S0 that extends in the movement direction. The travel distance calculation device 6 according to the sixth embodiment differs from the travel distance calculation device 1 according to the first embodiment in the arrangement of the light sources, but other features are similar, and the same components as those in the first embodiment will be assigned the same reference numerals and names and will not be described again.

[0063] FIG. 10 is a schematic diagram showing the overall configuration of a travel distance calculation device 6 according to a sixth embodiment. As shown in FIG. 10, the travel distance calculation device 6 includes a light source 10, an optical system 20, an optical sensor 30, and an information processing device 100. In the sixth embodiment, the light source 10 irradiates light onto the back surface of a sheet-shaped workpiece S0 that extends in the direction of movement. With this configuration, the travel distance calculation device 6 can acquire optical information about the surface of a workpiece, for example, made of a material that easily transmits light, based on the difference in the amount of light transmitted between a portion that easily transmits light and a portion that does not easily transmit light.

[0064] In addition, the present disclosure allows for free combination of the respective embodiments, modification of any of the components of the respective embodiments, or omission of any of the components of the respective embodiments. [Explanation of symbols]

[0065] 1, 2, 3, 4, 5, 6: Travel distance calculation device 10:Light source 20, 120: Optical system 21: First lens 22: Second lens 23: Third lens 30, 130: Optical sensor 100: Information processing device 100a: Processor 100b:Memory 100c: I / O port 100d: Processing circuit 101:Optical information acquisition section 102: Correlation value calculation unit 103: Travel distance calculation unit 104: Storage section L1, L2: Optical axis S0, S1, S2: Work

Claims

1. a light source that irradiates light onto a workpiece moving in the movement direction; an optical system that guides light from the workpiece irradiated by the light source along an optical axis that intersects with both a direction perpendicular to the surface of the workpiece extending along the movement direction and the movement direction; an optical sensor that acquires optical information of the surface based on light from the optical system; a movement distance calculation unit that calculates movement distance information regarding a movement distance of the workpiece during a period from the first time to the second time based on a correlation value indicating a correlation between first optical information acquired by the optical sensor at a first time and second optical information acquired by the optical sensor at a second time. A travel distance calculation device characterized by:

2. The optical system is disposed so that the optical axis of the optical system is perpendicular to the optical axis of the light source when viewed in the movement direction.

2. The travel distance calculation device according to claim 1.

3. The optical system is disposed at a position where specularly reflected light from the light source is incident on the surface.

2. The travel distance calculation device according to claim 1.

4. The optical system is disposed at a position where light from the light source is not specularly reflected by the surface.

2. The travel distance calculation device according to claim 1.

5. The light source irradiates light onto a specific portion of the workpiece extending in the movement direction, The optical sensor is arranged in a plane along a virtual plane perpendicular to the optical axis of the optical system, and has a plurality of light receiving elements that receive light from the optical system.

2. The travel distance calculation device according to claim 1.

6. The light source irradiates light onto a specific portion of the workpiece extending in the movement direction, the optical sensor includes a plurality of light receiving elements that are linearly arranged along the movement direction and receive light from the optical system; The optical system has a cylindrical lens that focuses light from the workpiece in a linear manner toward the plurality of light receiving elements.

2. The travel distance calculation device according to claim 1.

7. The light source, the optical system, and the optical sensor are arranged such that, when viewed in the movement direction, an optical axis of the light source, a principal surface of a lens included in the optical system, and a light receiving surface of the optical sensor that receives light intersect at one point.

2. The travel distance calculation device according to claim 1.

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