Inspection equipment, inspection method

Abstract

This technology provides the ability to accurately identify defects in booklets. [Solution] An inspection device 1 for inspecting an object made of stacked paper sheets, comprising a measuring unit 103 for measuring the shape of the end face of the object, and a determination unit 102 for determining whether or not there is a defect on the end face based on the measurement result of the measuring unit 103.

Description

Technical Field

[0001] The present invention relates to a technique for determining defects in booklets.

Background Art

[0002] In a general bookbinding process, first, a bundle of paper sheets such as printed sheets with characters, figures, etc. (paper sheet bundle) is used as the main body of the booklet by arranging them in page order to form a folded booklet. Then, after that, or in some cases, after attaching the cover to integrate the main body and the cover by a cover-attaching device, three-side cutting is performed by a three-side cutting machine, and the booklet is formed into a specified size.

[0003] In related technologies, there is known a bookbinding apparatus including an X-Y actuator that enables a moving part to move freely in a two-dimensional direction, a hand unit provided on the moving part of the X-Y actuator to hold the main body, a plurality of bookbinding units two-dimensionally arranged in the movable range of the hand unit to execute each process for bookbinding, and a control unit that controls the X-Y actuator. Based on the control of the control unit, the X-Y actuator moves the moving part to move the hand unit that holds the main body to a plurality of necessary bookbinding units among the plurality of bookbinding units in a predetermined order, and moves the hand unit to positions necessary for executing each process in the bookbinding unit where the hand unit is moved (see Patent Document 1 below).

[0004] By the way, checking whether there are defects such as folding of the main body in the booklet at any timing in such a bookbinding process, for example, after three-side cutting, has been conventionally performed. Here, the folding refers to the folding of the paper sheets included in the booklet, particularly corner folding. In order to prevent the shipment of booklets with defects such as such folding, at present, visual inspection by an operator is performed.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Patent No. 4604149 [Overview of the project] [Problems that the invention aims to solve]

[0006] The problem that this invention aims to solve is to provide a technology that can appropriately determine defects in booklets. [Means for solving the problem]

[0007] One aspect of the present invention is an inspection device for inspecting an object consisting of stacked sheets of paper, comprising a shape measuring unit for measuring the shape of the end face of the object, and a determination unit for determining whether or not there is a defect on the end face based on the measurement result of the shape measuring unit. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a technology that can appropriately determine defects in booklets. [Brief explanation of the drawing]

[0009] [Figure 1] This is a block diagram showing the configuration of the inspection apparatus according to the embodiment. [Figure 2] This is a schematic perspective view showing an inspection apparatus according to an embodiment. [Figure 3] This diagram illustrates the operation of the discharge conveyor and exclusion device according to the embodiment. [Figure 4] This diagram illustrates the operation of the discharge conveyor and exclusion device according to the embodiment. [Figure 5] This is a block diagram showing the functional configuration of the inspection device according to this embodiment. [Figure 6] This diagram illustrates the shape measurement results for objects being inspected in an aligned state. [Figure 7] This diagram illustrates the shape measurement results for an object being inspected that is in a misaligned state. [Figure 8]A diagram showing graphs as shape measurement results at each determination point shown in FIG. 7. [Figure 9] A diagram for explaining a determination threshold according to an embodiment. [Figure 10] A flowchart showing a folding inspection process according to an embodiment. [Figure 11] A flowchart showing a defective product exclusion process according to an embodiment.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In this specification and the drawings, components having substantially the same function are denoted by the same reference numerals, and redundant description is omitted.

[0011] (Configuration of the inspection device) FIG. 1 is a block diagram showing the configuration of an inspection device according to this embodiment. FIG. 2 is a schematic perspective view showing the inspection device according to this embodiment. FIGS. 3 and 4 are diagrams for explaining the operations of a discharge conveyor and an exclusion device included in the inspection device according to this embodiment.

[0012] The inspection device according to this embodiment uses a booklet after three-sided cutting by a three-sided cutting machine included in a wireless binding machine as an inspection object, and performs a folding inspection for determining the presence or absence of defects, specifically, the presence or absence of folding, on the booklet. Here, the booklet is a book with a cover obtained by laminating folded sheets or paper sheets (for example, album paper, printed or unprinted paper sheets, sheets such as postcards) stitched together by a stitching machine as a bundle and performing various bookbinding processes such as attaching a cover. The paper sheets according to this embodiment may also include this cover.

[0013] <00,00089>As shown in FIG. 1, the inspection device 1 includes a conveyance conveyor 10, a pair of sensors 20, a discharge conveyor 30, a moving device 40, and a control device 50. Hereinafter, each of these devices will be described in detail.

[0014] (Transfer conveyor 10) As shown in FIG. 2, the transfer conveyor 10 has a plurality of columnar transfer rollers 12 arranged in series along the horizontal X direction, and a plurality of, here three, stacked booklets W to be inspected are placed in a state where the top and bottom directions are preferably parallel to the Y direction substantially orthogonal to the X direction and conveyed in the X direction. For example, on the downstream side in the X direction of the transfer conveyor 10, a good product recovery box or the like for recovering the inspection object W determined to be a good product by the inspection device 1 is arranged.

[0015] In the present embodiment, the transfer roller 12 includes a free roller and a driving roller, and the driving roller is interposed between a certain number of free rollers. The driving roller is rotationally driven by a driving device 14 (see FIG. 1) controllably connected to the control device 50. In the present embodiment, the driving device 14 uses a servo motor that rotationally drives a rotating shaft for rotating the driving roller based on a pulse signal sent from the control device 50. The driving device 14 has an encoder 142, and the control device 50 adjusts the pulse width of the pulse signal sent based on the detection result as a pulse signal from the encoder 142, that is, based on the rotation amount and / or speed of the rotating shaft.

[0016] In the present embodiment, based on the detection result from this encoder 142, the position of the inspection object W can be calculated, and thereby the dimensions can be measured. Details of this dimension measurement will be described later. When dimension measurement is not performed, the driving device 14 does not need to have an encoder 142, and any actuator may be used as long as it can rotationally drive the driving roller.

[0017] (Sensor 20) As shown in Figure 2, the pair of sensors 20 are individually positioned on the top and bottom sides of the booklet group, which is the object to be inspected W. Each sensor measures the shape, particularly the unevenness, of the opposing top or bottom end face, i.e., each cut surface, in line. These are so-called visual inspection sensors (3D scanners). Specifically, the sensors 20 irradiate the opposing end faces of the object to be inspected W with a strip of laser light, and as the object to be inspected W is transported by the conveyor belt 10, the entire surface of the end face is scanned. The laser light diffusely reflected from the end face of the object to be inspected W is imaged onto an image sensor such as a CMOS image sensor of the sensor 20 and converted into an electrical signal. As a result, the sensor 20 can detect changes in the shape of the end face in three dimensions based on the reflection time and angle data of the laser light, and measure the shape of the entire end face. The pair of sensors 20 are each connected to the control device 50 so as to be able to transmit their shape measurement results, and the control device 50 makes a determination of folds in the object to be inspected W based on the shape measurement results. Details regarding the shape measurement results and the determination of folds will be described later.

[0018] The sensor 20 preferably incorporates an auto-scan mechanism capable of integrally driving the laser light source and the image sensor. Furthermore, the light source is preferably capable of emitting a high-brightness blue semiconductor laser light compared to a general LED. Blue semiconductor laser light enables high light focusing and sharp imaging, and also increases the light reception density. In addition, the sensor 20 preferably employs an optical system incorporating the Scheinproof principle to achieve full focus. It is also preferable to have a detection mechanism that detects the intrusion of the object to be inspected W into a predetermined measurement range, enabling laser light irradiation when the object enters the range; however, the laser light may be continuously irradiated. Reference numeral 22 in Figure 2 indicates the measurement range. Alternatively, the inspection device 1 may be equipped with a separate sensor as this detection mechanism, in addition to the sensor 20. The laser irradiation range can be appropriate in the X direction, but in the vertical direction, it is preferable that it covers the entire end face of the object to be inspected W.

[0019] One example of such a sensor is the auto-scan 3D sensor manufactured by Keyence Corporation. The LJ-S8000 series is particularly preferred. However, the system is not limited to this sensor; any sensor capable of measuring the shape of the top and bottom end faces of the object W being inspected can be used.

[0020] (Discharge conveyor 30) As shown in Figure 2, the discharge conveyor 30 has multiple cylindrical transport rollers 32 arranged in series along the horizontal Y direction, and transports defective items W, i.e., items that have been bent or whose dimensions deviate from a predetermined threshold range, by the inspection device 1, along a different path in the Y direction from the inspection items W that have been determined to be good. For example, a defective item collection box or the like is placed downstream of the discharge conveyor 30 in the Y direction to collect the inspection items W that have been determined to be defective.

[0021] In this embodiment, the transport roller 32, like the transport roller 12, includes free rollers and drive rollers, with drive rollers interposed between a certain number of free rollers. The drive rollers are rotationally driven by a drive device 34 (see Figure 1) that is controllably connected to the control device 50. Unlike the transport conveyor 10, the discharge conveyor 30 does not need to know the exact position of the inspection target W that has been determined to be defective, so a motor without an encoder may be used as the drive device 34.

[0022] (Mobile device 40) As shown in Figure 2, the moving device 40 is located downstream of the sensor 20 in the transport direction X, and moves the object to be inspected W, which has been determined to be defective by the inspection device 1, from the transport conveyor 10 to the discharge conveyor 30, thereby preventing defective products from being mixed into the transport path of good products. The moving device 40 mainly consists of a damming plate 42 and an extrusion plate 44.

[0023] The damming plate 42 is a plate-shaped member formed between the transport rollers 12 of the transport conveyor 10 and positioned below the gap 16 located near the upstream end of the discharge conveyor 30. The damming plate 42 is connected to the vertical drive device 422 shown in Figure 1 and is movable vertically by the vertical drive device 422, meaning it can extend and retract from the transport surface formed by the multiple transport rollers 12 of the transport conveyor 10. Therefore, as shown in Figure 3, the damming plate 42, when protruding from the transport surface, can dam the object to be inspected W being transported by the transport conveyor 10.

[0024] The extrusion plate 44 is a plate-shaped member positioned so that the transport conveyor 10 is located between it and the upstream end of the discharge conveyor 30. The extrusion plate 44 is connected to the horizontal drive device 442 shown in Figure 1 and is movable along the horizontal direction by the horizontal drive device 442. Therefore, the object to be inspected W, which is blocked by the damming plate 42 as shown in Figure 3, can be moved onto the discharge conveyor 30 by advancing toward the discharge conveyor 30, as shown in Figure 4.

[0025] The sizes of the damming plate 42 and the extrusion plate 44 are appropriate, but they do not necessarily need to be longer than the vertical length of the object to be inspected W, as shown in Figures 2-4. As long as they can contact the booklet located at the bottom layer of the object to be inspected W, the object to be inspected W can be dammed and moved.

[0026] The vertical drive unit 422 and the horizontal drive unit 442 are each controlled by the control unit 50 and can be driven at any desired timing. In this embodiment, the control unit 50 can calculate the position of the object to be inspected W from the sensor 20 based on the detection result of the encoder 142 from the start of measurement by the sensor 20. Therefore, if a fold has occurred as a result of the shape measurement, i.e., if it is determined to be a defective product, it can determine whether the defective object to be inspected W has reached the position where the damming plate 42 should be driven, and at the timing when it is determined that it has reached that position, the damming plate 42 can be driven via the vertical drive unit 422.

[0027] The vertical drive device 422 and the horizontal drive device 442 may be any device capable of reciprocating linear motion of the damming plate 42 and the push plate 44, such as a rotary drive device including a motor with a cam or crank mechanism, a hydraulic / pneumatic piston cylinder, a solenoid, etc.

[0028] (Control device 50) As shown in Figure 1, the control device 50 includes a CPU (Central Processing Unit) 52 that performs the main control of the control device 50, a memory 54 which is the CPU's work area, a storage device 56 which stores various information related to the folding inspection process by the inspection device 1, and an input / output device 58 which is the user interface.

[0029] The CPU 52 executes the BIOS, OS, general-purpose applications, and various programs read from the storage device 56 by loading them into memory 54. Examples of programs here include programs that cause the control device 50 to execute the fold inspection process (fold inspection method) described later. The control device 50 reads the various programs and uses the above-mentioned hardware resources to control the drive of the transport conveyor 10, sensor 20, discharge conveyor 30, and moving device 40. Other information stored in the storage device 56 includes, for example, the measurement range, the number and interval of judgment points, the judgment threshold, and the dimensional reference range of the object to be inspected W. Details about judgment points and judgment thresholds will be described later.

[0030] The input / output device 58 is a so-called control panel, which has, for example, pressable buttons and a display, preferably a touch panel display. The input / output device 58 displays shape information, which will be described later, to the operator, accepts operations from the operator, and accepts changes to various settings, such as inputting the number and interval of judgment points, judgment threshold, measurement range, and dimensional reference range of the object to be inspected W, which will be described later. The control device 50 may be configured as a PC (Personal Computer).

[0031] Figure 5 is a block diagram showing the functional configuration of the inspection device according to this embodiment. The inspection device 1 according to this embodiment includes a drive unit 101, a determination unit 102, a measurement unit 103, and a calculation unit 104 as its functions. These functions are realized through the cooperation of the various devices and hardware described above, mainly the CPU 52 and memory 54.

[0032] The drive unit 101 drives the transport conveyor 10, the discharge conveyor 30, and the moving device 40. The judgment unit 102 performs various judgments related to the bending inspection process and the defective product exclusion process described later. The measurement unit 103 performs shape measurement using the sensor 20 and acquires the shape measurement results. The calculation unit 104 acquires pulse signals from the encoder 142 and calculates the judgment reference line from the shape measurement results and calculates the dimensions of the object to be inspected W.

[0033] Next, we will explain the shape measurement results obtained by the sensor 20 and the method for determining folds from these measurement results. Figure 6 is a diagram illustrating the shape measurement results for an object to be inspected in an aligned state, and Figure 7 is a diagram illustrating the shape measurement results for an object to be inspected in an unaligned state. Figure 8 is a graph showing the shape measurement results at each judgment point shown in Figure 7. Figure 9 is a diagram illustrating the judgment threshold according to this embodiment. Note that the symbol Fo shown in Figure 7 indicates the folding of the paper sheets.

[0034] The shape measurement results obtained by the sensor 20 include three-dimensional values ​​for vertical (height), horizontal (length in the transport direction X), and depth (depth), including minute irregularities on the scanned end face. These values ​​are close to the actual measured values. Figures 6 and 7 show examples of the shape measurement results being displayed on the input / output device 58 as a three-dimensional model. In this embodiment, even if the object to be inspected W is in an aligned state where the end faces of each booklet W1 to W3 are aligned at a visual level, as shown in Figure 6, or in an unaligned state where each booklet is misaligned, that is, a booklet is rotated relative to an adjacent booklet, as shown in Figure 7, good shape measurement results can be obtained even if the object to be inspected W is in an unaligned state where, for example, the X-direction end of one booklet's end face is located about 10 mm behind or in front of the corresponding end of an adjacent booklet.

[0035] In the folding inspection process according to this embodiment, multiple judgment points are set along the longitudinal direction, that is, the direction parallel to the transport direction X, based on the shape measurement results, and a judgment reference line is calculated based on the values ​​of the judgment points. In Figure 8, the values ​​of the shape measurement results at the three judgment points P1 to P3 shown in Figure 7 are shown as a graph, with Figure 8(a) corresponding to judgment point P1, Figure 8(b) to judgment point P2, and Figure 8(c) to judgment point P3. The vertical axis De of this graph represents the depth (distance from the sensor 20), and the horizontal axis Le represents the height. In other words, Figure 8 can be said to be a cross-sectional view of the end face W of the object to be inspected, viewed from the opposite direction of the transport direction X at judgment points P1 to P3.

[0036] Figure 8(c) shows that the portion corresponding to booklet W5 exhibits an excessive decrease in value compared to the surrounding area, indicating that a slit-shaped recess has been formed on the edge. This means that the fold Fo is being measured accurately. Although only three judgment points are shown here for explanatory purposes, in reality, dozens, hundreds, or even thousands of judgment points are set at regular intervals, taking into account the type and size of the booklet. These judgment points can be changed as needed by the operator of the inspection device 1. A judgment reference line is generated for each of these judgment points.

[0037] Figure 9 is a diagram illustrating the judgment threshold according to this embodiment, and shows a graph of the shape measurement results at the same judgment point as in Figure 8(c). In this embodiment, the judgment reference line is curved (smoothed) using a known fitting process for each value of the shape measurement result. Various parameters such as the smoothing range (%) of the fitting process can be set appropriately depending on the type of booklet, but it is particularly preferable to set the smoothing range to approximately 5%. In addition, it may be generated by a process that can be curved, such as an existing smoothing process represented by a moving average. The symbol Od shown in Figure 9 is the original data of the judgment point P3, in other words, a group of numerical values ​​(shape information) that shows the shape of a part of the end face of the object to be inspected W, and the symbol S is the judgment reference line (judgment reference value) generated based on the original data Od. In the fold inspection process, the judgment unit 102 calculates the numerical difference (absolute value) of the depth De at each position on the horizontal axis Le between the judgment reference line S and the original data Od, and each numerical difference is a predetermined judgment threshold T h Whether or not a fold has occurred is determined by whether or not it exceeds (for example, 3 mm). Here, the numerical difference T1 on the horizontal axis Le1 is the determination threshold T h It was found that it exceeded the threshold T on the end face, and therefore the determination threshold T h It can be seen that there is a depression with a depth exceeding [a certain value]. In other words, the fold Fo occurring in booklet W5 can be accurately detected.

[0038] (Folding inspection process) Next, the folding inspection process according to this embodiment will be described in detail. Figure 10 is a flowchart of the folding inspection process according to this embodiment. This flow is executed when the power to the inspection device 1 is turned on and the start of the folding inspection process is input by the operator via the input / output device 58. Alternatively, it may be executed when the object to be inspected W is acquired from the three-sided trimmer.

[0039] First, the drive unit 101 sends a pulse signal, which causes the drive roller 14 to rotate and operate the conveyor belt 10 (S101). After operation, the determination unit 102 determines whether or not the object to be inspected W has entered the measurement range of the sensor 20 (S102). If the object to be inspected W has not entered the measurement range (S102, NO), this determination is repeated. On the other hand, if the object to be inspected W has entered the measurement range (S102, YES), the measurement unit 103 scans the object to be inspected W using the sensor 20.

[0040] The timing of the start of scanning is preferably approximately simultaneous with the detection of intrusion. The timing of the end of scanning is when the object W to be inspected deviates from the measurement range. At both the start and end of scanning timings, the calculation unit 104 stores the pulse signals from the encoder 142. In other words, the memory 54 or storage device 56 stores how many pulses after the start of scanning, that is, how many pulses of pulse signal were acquired by the control device 50 before the end of scanning. In other words, the pulse signals can be said to be information indicating the amount of movement of the object W to be inspected. These stored pulse signals are used for calculating the dimensions of the object W to be inspected, as described later. Pulse signals from the end of scanning timing are also continuously acquired and stored. These stored pulse signals are used during the defective product exclusion process, as described later, to remove the object W determined to be defective from the conveyor belt 10.

[0041] After scanning is complete, the measurement unit 103 acquires shape measurement results from each of the pair of sensors 20 (S104), and the calculation unit 104 calculates a judgment reference line S for each judgment point based on the shape measurement results of the top end face and the bottom end face, and based on the setting information for the judgment points that have been set in advance (S105). Subsequently, the calculation unit 104 calculates the numerical difference between the judgment reference line S and the original data Od value for each length of the height direction of the object W to be inspected (horizontal axis Le shown in Figures 8 and 9), and performs this calculation for each judgment point (S106).

[0042] After calculating the numerical difference, the determination unit 102 determines that the absolute value of each calculated numerical difference is the determination threshold T. hBased on whether or not it exceeds a certain value, it is determined whether or not a fold has occurred in the object W to be inspected corresponding to the current shape measurement result (S107). If it is determined that no fold has occurred (S107, NO), the calculation unit 104 calculates the dimensions of the object W to be inspected in the transport direction X corresponding to the current shape measurement result based on the pulse signals recorded from the scan start timing to the scan end timing, and, if applicable, the elapsed time (S108).

[0043] After the dimension calculation, the determination unit 102 determines whether the calculated dimension is within a preset dimensional reference range (S109). If the calculated dimension is within the preset dimensional reference range (S109, YES), the determination unit 102 determines that the inspection object W corresponding to the current shape measurement result is a good product (S110), and proceeds to the determination process in step S102. At this time, the continuous acquisition of pulse signals from the end of scanning of the inspection object W corresponding to the current shape measurement result may be stopped, and the stored pulse signals may be deleted.

[0044] On the other hand, if the calculated dimensions are outside the preset dimensional reference range (S109, NO), the determination unit 102 determines that the inspection object W corresponding to the current shape measurement result is a defective product (S111). Pulse signals from the end of scanning corresponding to the inspection object W determined to be a defective product are continuously acquired, and information indicating a defective product is associated with these signals, and the process proceeds to the determination process in step S102. Similarly, in step S107, if the absolute value of any one of the calculated numerical differences is within the determination threshold T, h If there are any items that exceed this limit and it is determined that a fold has occurred (S107, YES), the process proceeds to step S111, which determines that the item is defective.

[0045] (Defective product exclusion process) Next, we will explain in detail the defective product exclusion process, which is performed in parallel with the folding inspection process. Figure 11 is a flowchart of the defective product exclusion process according to this embodiment. This flow is executed periodically when the object W to be inspected is determined to be a defective product.

[0046] First, the determination unit 102 determines whether the inspection object W determined to be defective has reached a predetermined exclusion position, that is, a position where it can reliably block only the inspection object W after the damming plate 42 of the moving device 40 has advanced, without obstructing the inspection object W determined to be good (S201). Since the pulse signal is continuously acquired even after the scanning is completed, and the distance from the measurement range of the sensor 20 to the exclusion position is known, it is possible to reliably determine that the inspection object W determined to be defective has reached the exclusion position based on these factors.

[0047] If the object W determined to be defective has not reached the exclusion position (S201, NO), this determination process continues. On the other hand, if the object W determined to be defective has reached the exclusion position (S201, YES), the drive unit 101 sends a control signal and moves the damming plate 42 upward using the vertical drive device 422 (S202), damming the object W determined to be defective. Next, the drive unit 101 sends a control signal and moves the push plate 44 toward the discharge conveyor 30 using the horizontal drive device 442 (S203), moving the object W determined to be defective from the transport conveyor 10 onto the discharge conveyor 30. After movement, the drive unit 101 retracts the damming plate 42 and the pushing plate 44 using the vertical drive unit 422 and the horizontal drive unit 442 (S204). Almost simultaneously, it sends a control signal to drive the drive rollers with the drive unit 34 to transport the moved inspection object W (S204), and then proceeds back to the judgment process in step S201. When steps S202 to S204 are being executed, it is preferable that the transport of other inspection objects W by the transport conveyor 10 continues in order to shorten the inspection time. In other words, it is preferable that the damming and pushing are completed before the inspection object W that is transported after the inspection object W that has been determined to be defective passes the exclusion position.

[0048] As described above, this embodiment allows for the acquisition of shape measurement results showing the three-dimensional shape of the top and bottom end faces of the transported inspection object W. Based on these results, the presence or absence of folds can be accurately determined. Therefore, compared to visual checks by workers, defects in the booklet can be appropriately determined without errors due to fatigue, and personnel costs can be reduced, as well as inspection speed can be improved. Furthermore, since dimensional measurement can be performed simultaneously with the detection of folds, defects during three-sided trimming can also be appropriately determined. In addition, since defective inspection objects W can be reliably separated from good products, it is possible to prevent situations where defective products are mixed in with good products. Moreover, according to this embodiment, even if the thickness of the booklet changes, as long as the size in the longitudinal and transverse directions does not change, the inspection device 1 can perform the fold inspection process without changing its settings, which is extremely convenient. Furthermore, since the shape measurement results are obtained using a laser light sensor 20, a light source is not required compared to obtaining shape measurement results from images captured by a camera, thus eliminating the need for adjustment work and reducing mechanical and time costs.

[0049] In this embodiment, the inspection device 1 is described as a separate device from the perfect binder, but this is not the only way to do so. The inspection device 1 and the binding device such as the perfect binder may be configured as an integrated unit, in which case the control device 50 will be shared with the control device of the binding device, and the functions of the control device 50 will be performed by the control device. Furthermore, although the inspection device 1 was used to inspect stacked booklets after three-sided trimming, a single booklet may be used as the object of inspection W, or the inspection device 1 may be interposed before three-sided trimming, for example after collating or after attaching the cover, to perform folding inspection processing and defective product exclusion processing, or the object of inspection W may be stacked paper sheets with covers instead of booklets.

[0050] Furthermore, in this embodiment, the shapes of the top and bottom end faces were measured, but the end face of the front end may be measured instead. In this case, for example, a new sensor 20 can be installed above the object W to be inspected and on the transport direction X side by providing a rail extending in the transport direction Y and a slider that can reciprocate on the rail, and attaching the new sensor 20 to the slider. In this case, it is necessary to stop the transport conveyor 10 when measuring the front end face. On the other hand, the rail may be constructed to be movable further in the transport direction X side, and the rail may be moved at the same speed as the transport of the object W to be inspected by the transport conveyor 10, thereby measuring the front end face without stopping the transport conveyor 10.

[0051] Furthermore, if there is excessive misalignment between stacked booklets, it may be impossible to perform accurate dimensional measurements. Therefore, it is possible to determine whether or not such misalignment has occurred based on the shape measurement results. For example, if misalignment has occurred, excessive irregularities will appear on the end face shape as shown in Figures 8(a) and 8(c). Therefore, for example, if the difference between the minimum and maximum depth values ​​on the judgment reference line S is greater than or equal to a predetermined threshold, it may be determined that there is excessive misalignment between the booklets of the object to be inspected W.

[0052] Furthermore, in this embodiment, the inspection method of the inspection device 1 was described as a folding inspection process targeting folding as a defect on the top and bottom end faces of the object to be inspected W. However, by adjusting the value of the judgment threshold and reusing the folding inspection process, it is also possible to inspect defects other than folding, such as excessive burr generation during cutting.

[0053] Furthermore, in this embodiment, if there is a change in the length and width of the booklet, it is preferable to adjust the distance between each of the pair of sensors 20 and the object W to be inspected. On the other hand, this adjustment may be performed automatically. For example, a rail extending in the transport direction Y and a slider capable of reciprocating on the rail are provided, the sensor 20 is placed on the slider, and the size of the booklet is input to the inspection device 1 via the input / output device 58. By moving the slider along the rail, the distance between the sensor 20 and the object W to be inspected can be automatically adjusted. It is preferable to use linear guides or the like that can be positioned with high precision for such a slider and rail. It is also preferable to store a list that associates the size of the booklet with the slider position in a storage device 56, and when the size of the booklet is input, the list is read from the storage device 56 by the drive unit 101 or the like, and the slider is moved automatically.

[0054] While embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications are possible without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as described in the claims. [Explanation of symbols]

[0055] 1. Inspection device 10. Conveyor belt (first conveying section) 20. Sensor (Shape Measurement Unit) 30. Discharge conveyor (second transport section) 40 Mobile device (moving part) 42 Damming plate (damming section) 44. Extruded plate (extrusion section) 102 Judgment section 103 Measuring part (shape measuring part) 104 Calculation Unit (Reference Surface Calculation Unit, Dimension Calculation Unit) T h Judgment threshold (predetermined threshold) W: Object to be inspected (object)

Claims

1. An inspection device for inspecting an object which is a collection of multiple booklets made up of stacked sheets of paper, A shape measuring unit for measuring the shape of the end face of the object in which the paper sheets are stacked in a substantially vertical direction, A reference surface calculation unit calculates a reference surface by smoothing shape information, which is a group of numerical values ​​indicating the shape of the end face of the object, included in the measurement results of the shape measuring unit, A determination unit that determines whether or not there is a defect on the end face based on the measurement result and the reference surface, Equipped with, The shape measuring unit has a sensor for obtaining the measurement result, which includes information on the length, width, and depth of the end face, by irradiating the end face with laser light to scan the end face and measuring the three-dimensional shape of the end face based on the reflected light from the end face. The determination unit calculates the numerical difference between the measurement result and the reference surface at the same position, and if there is a numerical difference that exceeds a predetermined threshold, it determines that there is a depression with a depth exceeding the threshold relative to the reference surface, and determines that there is a defect. Inspection device.

2. The aforementioned defect is the folding of the paper sheets contained in the object. The inspection apparatus according to claim 1.

3. The system further comprises a first conveying unit that conveys the aforementioned object in one direction, The shape measuring unit detects whether the object has entered the measurement range while the object is being transported by the first transport unit, and measures the shape of the end face of the object if it has entered the measurement range. The inspection apparatus according to claim 1.

4. A first transport unit for transporting the aforementioned object, A second transport unit transports the object that has been determined to have the defect, and the transport route is different from that of the first transport unit. If the determination unit determines that the object has a defect, the moving unit moves the object from the first transport unit to the second transport unit. The inspection apparatus according to claim 1, further comprising:

5. The aforementioned movable part is A damming section is positioned below the first conveying section and moves upward to block the object being conveyed by the first conveying section, An extrusion unit pushes the object being held back by the damming unit to move it to the second transport unit. The inspection apparatus according to claim 4, having the following features.

6. A first transport unit for transporting the aforementioned object, A dimension calculation unit calculates the dimensions of the object based on information indicating the amount of movement of the object by the first transport unit from the start of measurement of the end face of the object by the shape measuring unit to the end of measurement, and The inspection apparatus according to claim 1, further comprising:

7. An inspection method for inspecting an object which is a stack of paper sheets arranged in multiple booklets using an inspection device, By irradiating the end face of the object, in which the paper sheets are stacked in a substantially vertical direction, with a laser beam, the end face is scanned, and the three-dimensional shape of the end face is measured based on the reflected light from the end face, thereby obtaining measurement results including information on the length, width, and depth of the end face. The shape information, which is a set of numerical values ​​indicating the shape of the end face of the object, included in the measurement results, is smoothed to calculate the reference surface. Based on the measurement results and the reference surface, it is determined whether or not the object has a defect. In the determination described above, the numerical difference between the measurement result and the reference surface at the same position is calculated, and if the numerical difference exceeds a predetermined threshold, it is determined that there is a depression with a depth exceeding the threshold relative to the reference surface, and the defect is determined to exist. Testing method.

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