Image forming system, image forming method, and program

Abstract

To achieve, with a single-element detector, acquisition of a one-dimensional or two-dimensional image of a moving subject, or acquisition of a one-dimensional or two-dimensional image of the subject while moving.SOLUTION: An image forming system 100 comprises: an illumination projection unit 12 that irradiates a measurement object moving at a substantially uniform speed with light in a plurality of illumination patterns; a detection unit 13 that detects the intensity of reflected light from the measurement object irradiated with the light in the illumination patterns; an illumination control unit (control unit 11) that causes the illumination projection unit 12 to sequentially switch between the plurality of illumination patterns to irradiate the measurement object with light; and a creation unit (control unit 11) that creates a reconstructed image that is two-dimensionally reconstructed from the illumination patterns and the intensity of reflected light corresponding to the illumination patterns.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image forming system, an image forming method, and a program. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in visual inspection of an object, a single-element detector such as a photodiode or a PMT (photomultiplier tube) may be used. As a method for acquiring one-dimensional or two-dimensional images using a single-element detector, a technique called single pixel imaging (SPI), as disclosed in Patent Documents 1 and 2, is known.

[0003] SPI is a technique in which an object is illuminated with different illumination patterns multiple times, the scattered light intensity is acquired using a single-element detector, and a one- or two-dimensional image is reconstructed based on the detector's signal intensity in response to the illumination pattern. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2020-96272 [Patent Document 2] Patent Publication No. 2021-57848 Summary of the Invention [Problem to be solved by the invention]

[0005] Due to the nature of the technique, SPI requires that different lighting patterns be projected onto the same location multiple times, so it is assumed that both the object and the lighting pattern projection device are stationary.

[0006] Therefore, when considering visual inspection of objects during the manufacturing process in a factory, it is difficult to keep products / parts placed on a conveyer belt or products produced roll-to-roll. Furthermore, these products are produced continuously and do not have separate sections for each item. For this reason, SPI has not been applied to visual inspection of moving objects. SPI has also not been applied when performing visual inspection of moving objects.

[0007] SUMMARY OF THE DISCLOSURE It is an object of the present invention to provide a single element detector for acquiring one or two dimensional images of a moving object or for acquiring one or two dimensional images of an object while it is moving. [Means for solving the problem]

[0008] In order to solve the above problems, the image forming system of the present invention comprises: an illumination projection unit that irradiates light of a plurality of illumination patterns onto a measurement object moving at a substantially uniform speed; a detection unit that detects a light intensity of reflected light from the measurement object due to the light of the illumination pattern; an illumination control unit that sequentially switches the illumination pattern from among the plurality of illumination patterns and causes the illumination projection unit to emit light; a generation unit that generates a two-dimensional reconstructed image from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern; The present invention is characterized by comprising:

[0009] In order to solve the above problems, the image forming system of the present invention comprises: an illumination projection unit that moves at a substantially uniform speed and irradiates a measurement object with light of a plurality of illumination patterns; a detection unit that detects a light intensity of reflected light from the measurement object due to the light of the illumination pattern; an illumination control unit that sequentially switches the illumination pattern from among the plurality of illumination patterns and causes the illumination projection unit to emit light; a generation unit that generates a two-dimensional reconstructed image from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern; The present invention is characterized by comprising:

[0010] The image forming method of the present invention further comprises the steps of: A plurality of illumination patterns are sequentially switched to irradiate a measurement object moving at a substantially uniform speed, Detecting the light intensity of the light of the illumination pattern reflected from the measurement object; A reconstructed image is generated that is two-dimensionally reconstructed from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern.

[0011] The image forming method of the present invention further comprises the steps of: The object is irradiated with light from multiple illumination patterns by moving at a substantially constant speed and switching between them in sequence. Detecting the light intensity of the light of the illumination pattern reflected from the measurement object; A reconstructed image is generated that is two-dimensionally reconstructed from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern.

[0012] In addition, the program of the present invention is A computer of an image forming system including an illumination projection unit that irradiates light of a plurality of illumination patterns onto a measurement object moving at a substantially uniform speed, and a detection unit that detects the light intensity of the reflected light from the measurement object due to the light of the illumination patterns, an illumination control unit that sequentially switches the illumination pattern from among the plurality of illumination patterns and causes the illumination projection unit to emit light; a generation unit that generates a two-dimensional reconstructed image from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern; Function as.

[0013] In addition, the program of the present invention is A computer of an image forming system including an illumination projection unit that moves at a substantially uniform speed and irradiates a measurement object with light of a plurality of illumination patterns, and a detection unit that detects the light intensity of reflected light from the measurement object due to the light of the illumination patterns, an illumination control unit that sequentially switches the illumination pattern from among the plurality of illumination patterns and causes the illumination projection unit to emit light; a generation unit that generates a two-dimensional reconstructed image from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern; Function as. Effect of the Invention

[0014] The present invention allows one to obtain one or two dimensional images of a moving object or to obtain one or two dimensional images of an object while it is moving with a single element detector. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of an image forming system according to a first embodiment. [Diagram 2] 1 is a block diagram showing a functional configuration of an image forming system according to a first embodiment. [Diagram 3] 1 is an example of a one-dimensional structure of an illumination projection unit. [Figure 4] 1 is an example of a one-dimensional illumination pattern. [Diagram 5] 4 is a flowchart of an image forming process. [Figure 6] FIG. 13 is a diagram illustrating the relationship between a scan period and a detection time. [Figure 7] FIG. 11 is a schematic diagram showing a schematic configuration of an image forming system according to a second embodiment. [Figure 8] 1 is an example of a two-dimensional structure of an illumination projection unit. [Figure 9] 1 is an example of a two-dimensional illumination pattern. [Figure 10] 4 is a flowchart of an image forming process. [Figure 11]1A and 1B are diagrams illustrating the relationship between the moving direction of an object and an illumination pattern irradiated to the same location. [Figure 12] FIG. 13 is a schematic diagram showing a schematic configuration of an image forming system according to a third embodiment. [Figure 13] FIG. 13 is a schematic diagram showing a schematic configuration of an image forming system according to a fourth embodiment. [Figure 14] FIG. 13 is a schematic diagram showing a schematic configuration of an image forming system according to another embodiment. [Figure 15] FIG. 13 is a schematic diagram showing a schematic configuration of an image forming system according to another embodiment. [Figure 16] FIG. 13 is a schematic diagram showing a schematic configuration of an image forming system according to another embodiment. [Figure 17] FIG. 13 is a schematic diagram showing a schematic configuration of an image forming system according to another embodiment. [Figure 18] 11 is a diagram showing the relationship between a scan period and a detection time in a conventional image forming system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the embodiments of the present invention will be described with reference to the drawings. However, the embodiments described below are subject to various limitations that are technically preferable for implementing the present invention, but the technical scope of the present invention is not limited to the following embodiments and illustrated examples. In particular, the drawings are simplified for the convenience of explanation, and the ratio of the illumination pattern to the object may differ.

[0017] First Embodiment (Configuration of Image Forming System) 1 is a schematic diagram showing a schematic configuration of an image forming system 100 according to a first embodiment. The image forming system 100 is used to output information about the appearance of a target object that is mainly a non-luminous object.

[0018] Fig. 1 shows an example of observing a measurement object H having a glossy surface such as a metallic electric saw blade. Fig. 2 is a block diagram showing the functional configuration of an image forming system 100 according to this embodiment. Here, the measurement object H, that is, the electric saw blade, is placed on a base 18 that moves at a substantially constant speed.

[0019] As shown in FIGS. 1 and 2, the image forming system 100 includes a control unit 11, an illumination projection unit 12, a detection unit 13, a storage unit 14, a display unit 15, an operation unit 16, a communication unit 17, and the like.

[0020] In the image forming system 100, a one-dimensional illumination pattern P is sequentially changed by an illumination projection unit 12 having a one-dimensional structure at every fixed period (scan period s), and is irradiated onto a measurement object H moving at a substantially constant speed. Then, a detection unit 13 detects reflected light from the measurement object H, and sends a time-varying light receiving signal S to a control unit 11. Then, based on the sequentially changed one-dimensional illumination patterns P and the one-dimensional light receiving signals S corresponding to each one-dimensional illumination pattern P, the control unit 11 generates a one-dimensionally reconstructed reconstructed image (first image) at every fixed period (scan period s) using SPI technology, and generates a two-dimensional second image by arranging the first images.

[0021] The control unit 11 is composed of a CPU (Central Processing Unit), a RAM (Random Access Memory), etc. The control unit 11 is connected to each part (illumination projection unit 12, detection unit 13, storage unit 14, display unit 15, operation unit 16, communication unit 17) of the image forming system 100, and controls the operation of each part. In addition, the control unit 11 executes various processes including an image forming process described later in cooperation with a program stored in the storage unit 14. The control unit 11 controls the illumination pattern P of the illumination projection unit 12 as an illumination control unit. The control unit 11 also controls the scan period s and the detection time t. Here, the scan period s is the time for the image forming system 100 to one-dimensionally read (scan) the measurement object H for each fixed distance d (movement distance d) that the measurement object H moves. In other words, it is the time for the measurement object H to move by the fixed distance d. Note that the illumination pattern P irradiation area of ​​the measurement object H may be read (scanned) for each. The detection time t is the time for all illumination patterns P to be sequentially irradiated and the detection unit 13 to detect the reflected light. The relationship between the scan period s and the detection time t will be described in detail later. In addition, the control unit 11 acquires the light intensity (received light signal S) corresponding to the illumination pattern P from the detection unit 13, and generates a one-dimensionally reconstructed first image from the illumination pattern P and the light intensity (received light signal S) at regular intervals (scan period s). Moreover, the control unit 11 generates a new second image based on a plurality of first images generated at regular intervals (scanning intervals s).

[0022] The illumination projection unit 12 is, for example, a one-dimensional structure projector using a DMD (Digital Mirror Device). Note that the illumination projection unit 12 may be various types of projector and is not limited to a projector using a DMD. As shown in FIG. 3, the illumination projection unit 12 sequentially changes a one-dimensional illumination pattern P shown in FIG. The resolution of the one-dimensional illumination pattern P irradiated by the illumination projection unit 12 affects the resolution of the reconstructed image, and the number of one-dimensional illumination patterns P irradiated also affects the resolution of the reconstructed image. Although the frame rate of the DMD is 60 Hz or 120 Hz, the two-dimensional illumination pattern P per unit time can be increased by the following method. Due to its fundamental characteristics, the DMD is capable of projecting image bits in sequence. Generally, one pixel of an image is composed of 24 bits in total, 8 bits for each of RGB, and each bit corresponds to the clock frequency of the DMD as one image and is projected in sequence. However, an image in which one pixel is expressed by 1 bit cannot express gradations, and only so-called black and white images can be projected. For example, by using an image expressed as a so-called black and white image as the lighting pattern, such as Hadamard illumination, it is possible to project an image 24 times the frame rate per unit time.

[0023] The detection unit 13 measures the light intensity (light receiving signal S) of the reflected light from the measurement object H in response to the light of each illumination pattern P that is sequentially irradiated. The detection unit 13 may be, for example, a two-dimensional sensor such as a CCD (Charge-Coupled Device), a one-dimensional sensor such as a line CCD, an array of photodiodes (photodetectors), a single photodiode (photodetector), or the like.

[0024] The storage unit 14 is composed of a non-volatile semiconductor memory, a hard disk, etc., and stores programs executed by the control unit 11, data necessary for executing the programs, the illumination pattern P, the light receiving signal S of the detection unit 13, various generated images, the shooting history, etc. The illumination pattern P is created by the control unit 11. The illumination pattern P may also be stored in the storage unit 14 in advance.

[0025] The display unit 15 displays an operation screen, the operating status of the image forming system 100, etc. on the display in accordance with the display control of the control unit 11.

[0026] The operation unit 16 includes a group of keys used for input operations such as starting processing, as well as a touch panel that is integrated with the display of the display unit 15, and generates operation signals in response to these operations and outputs them to the control unit 11.

[0027] The communication unit 17 includes a communication interface and communicates with external devices on the network.

[0028] (Image formation processing) The flow of the image formation process will be described with reference to Fig. 5. It is assumed that all the illumination patterns P are stored in the storage unit 14.

[0029] First, the control unit 11 causes the illumination projection unit 12 to irradiate one illumination pattern P onto the measurement object H in a certain scan period s (step S11).

[0030] Next, the control unit 11 acquires a light reception signal S representing light received from the object to be measured H from the detection unit 13 (step S12).

[0031] Next, the control unit 11 judges whether or not all the illumination patterns P have been irradiated by the illumination projection unit 12 (step S13). If all the illumination patterns P have been irradiated by the illumination projection unit 12 (step S13; YES), the process proceeds to step S14, and if not all the illumination patterns P have been irradiated by the illumination projection unit 12 (step S13; NO), the process proceeds to step S11, where the control unit 11 causes the illumination projection unit 12 to irradiate the next illumination pattern P.

[0032] Next, the control unit 11 reconstructs a one-dimensional image (first image) from the one-dimensional illumination pattern P and the light receiving signal S in a certain scan period s (step S14). Specifically, the measurement object H is considered to be substantially stationary during the detection time t in a certain scan period s, and the control unit 11 reconstructs a one-dimensional image (first image) using SPI from all the one-dimensional illumination patterns P sequentially irradiated onto the same location of the measurement object H and the light receiving signal S corresponding to each illumination pattern P. That is, a one-dimensional image (first image) of the illumination pattern P irradiated area of ​​the measurement object H is reconstructed.

[0033] Next, the control unit 11 generates a two-dimensional second image using the first image in each scan period s (step S15). Specifically, the control unit 11 generates the two-dimensional second image by arranging the first images in each scan period s in the order of the scan period s.

[0034] Next, the control unit 11 displays the second image on the display unit 15 (step S16).

[0035] Next, the control unit 11 determines whether the inspection is finished based on an instruction from the operation unit 16 (step S17). If the inspection is finished (step S17; YES), the image formation process ends, and if the inspection is not finished (step S17; NO), the process proceeds to step S18. Note that the control unit 11 may automatically determine whether the inspection is finished. For example, if there is an abnormality in the measurement object H on the second image, the control unit 11 automatically determines and ends the inspection.

[0036] Next, the control unit 11 judges whether the scan period s has elapsed since the timing when the illumination projection unit 12 irradiated the measurement object H with the first illumination pattern P in step S11 (step S18). If the scan period s has elapsed (step S18; YES), the process proceeds to step S11, where all illumination patterns P are sequentially irradiated again, and if the scan period s has not elapsed (step S18; NO), the process proceeds to step S18. That is, step S18 is repeated until the scan period s has elapsed.

[0037] Here, the relationship between the scan period s and the detection time t will be described using Fig. 6 and the process of Fig. 5. The detection time t is the time it takes for all the illumination patterns P to be sequentially irradiated and the detection unit 13 to detect the reflected light, and therefore refers to the time from when the loop of the processes from step S11 to step S13 is started (step S11) to when it is ended (step S13; YES). On the other hand, the scan period s is the time it takes for the image forming system 100 to one-dimensionally read the measurement target H for each illumination pattern P irradiated area of ​​the measurement target H, and therefore refers to the time from when the loop of the processes from step S11 to step S18 is started (step S11) to when it is ended (step S18; YES). FIG. 18 is a diagram showing the relationship between the scan period s and the detection time t in the case where a conventional line sensor camera or a standard SPI is applied one-dimensionally. In the conventional line sensor camera, the feed speed, scan rate (scan period s), and exposure time (detection time t) of the target object are controlled to continuously acquire images. Therefore, in order to acquire a suitable image, the feed speed and scan rate are restricted by the condition scan rate = feed speed / resolution, and in order to acquire an image of the target object that is almost stationary, it is necessary to make the exposure time ≦ scan rate as shown in FIG. 18(a) and to make the exposure time sufficiently short. In addition, in the SPI using the conventional illumination pattern with one-dimensional structure, the illumination pattern is switched in sequence repeatedly as 1, 2, 3···N, 1, 2, 3···N, ···, so the scan period and the detection time t must be roughly the same.

[0038] Moreover, the processes from step S14 to step S17 are performed in parallel with steps S11 to S13 and step S18. That is, even if the reconstruction of the first image in step S14, the generation of the second image in step S15, the display of the second image in step S16, and the process of determining whether the examination is completed in step S17 are prolonged and not completed, if the scan period s has elapsed since the timing of irradiating the first illumination pattern P in step S11, it is determined in step S18 that the scan period s has elapsed (step S18; YES), and the process proceeds to step S11.

[0039] <Second embodiment> 7 is a schematic diagram showing a schematic configuration of an image forming system 100 according to the second embodiment. The following describes aspects different from the first embodiment.

[0040] In the image forming system 100, a one-dimensional illumination pattern P is sequentially changed by the illumination projection unit 22 having a two-dimensional structure at every fixed period (scan period s), and is irradiated onto a measurement object H moving at a substantially constant speed. Then, the detection unit 13 detects the reflected light from the measurement object H, and sends a time-varying light receiving signal S to the control unit 11. Then, based on the sequentially changed one-dimensional illumination pattern P and the one-dimensional light receiving signal S corresponding to each illumination pattern P, the control unit 11 generates a one-dimensionally reconstructed image (first image) at every fixed period (scan period s) using SPI technology, and generates a two-dimensional second image by arranging the first images.

[0041] The illumination projection unit 22 is, for example, a two-dimensional projector using a DMD (Digital Mirror Device). As shown in FIG. 8, the illumination projection unit 22 sequentially changes, for example, the two-dimensional illumination pattern P shown in FIG. 9 to a row-by-row (P[0], P[1], P[2]...P[N-1]; one-dimensional illumination pattern P), and irradiates the measurement object H with the pattern.

[0042] (Image formation processing) The flow of the image formation process will be described with reference to Fig. 10. It is assumed that all the illumination patterns P are stored in the storage unit 14. In Fig. 10, all the illumination patterns P refer to the one-dimensional illumination patterns P of all the rows of the two-dimensional illumination patterns P, and one illumination pattern P refers to the one-dimensional illumination pattern P for each row.

[0043] First, steps S21 to S23 are the same as steps S11 to S13 in FIG.

[0044] Next, the control unit 11 judges whether all the illumination patterns P have been projected by the illumination projection unit 22 onto the same location of the measurement object H (step S24). Specifically, for example, when all the illumination patterns P are projected sequentially the number of rows of two-dimensional illumination patterns P, all the illumination patterns P are projected onto a portion of the measurement object H at a distance d from the front end in the movement direction, so that a one-dimensional image (first image) can be reconstructed in step S25. When the control unit 11 determines that all the illumination patterns P have been irradiated to the same location of the measurement object H by the illumination projection unit 22 (step S24; YES), the process proceeds to step S25, where a one-dimensional image (first image) is reconstructed. On the other hand, when the control unit 11 determines that the illumination patterns P have not been irradiated (step S24; NO), the process proceeds to step S28.

[0045] Here, the method of reconstructing the first image in step S25 will be described with reference to Fig. 11. Fig. 11 shows a one-dimensional illumination pattern P sequentially irradiated onto the measurement object H in each scan period s by the illumination projection unit 22. The arrow shown to the left of the measurement object H indicates the movement direction of the measurement object H. FIG. 11(a) shows a case where the movement direction of the measurement object H is the same as the movement direction of the row of one-dimensional illumination patterns P in the two-dimensional illumination pattern P, while FIG. 11(b) shows a case where the movement direction of the measurement object H is opposite to the movement direction of the row of one-dimensional illumination patterns P in the two-dimensional illumination pattern P.

[0046] Here, the measurement object H moves by L / N (=d) per scan period s, where L is the length of the illumination area illuminated by the illumination projection unit 22 in the direction of movement of the measurement object H. More precisely, it is desirable to move by L / (N+1) in the case of Fig. 11(a), and by L / (N-1) in the case of Fig. 11(b). Then, the same location on the measurement object H is irradiated with, for example, a one-dimensional illumination pattern P surrounded by a thick frame in FIG. That is, to be precise, in the case of FIG. 11(a), all the illumination patterns P are sequentially irradiated (the number of columns−1) times of the two-dimensional illumination pattern P, and at the time when the last one-dimensional illumination pattern P of the illumination pattern P in the scan period s immediately after that is irradiated, all the illumination patterns P are irradiated to a portion of the measurement object H at a distance d from the front end in the movement direction of the measurement object H. In the case of FIG. 11(b), all the illumination patterns P are sequentially irradiated (the number of columns−1) times of the two-dimensional illumination pattern P, and at the time when the last one-dimensional illumination pattern P is irradiated immediately after that, all the illumination patterns P are irradiated to a portion of the measurement object H at a distance d from the front end in the movement direction of the measurement object H. Then, the reconstruction of the first image in step S25 can be started.

[0047] When the two-dimensional illumination pattern P is based on an orthogonal basis, the image reconstruction in step S25 is performed using the following equation (1). 9, the two-dimensional illumination pattern P has M rows and N columns, and the two-dimensional second image (measurement object H) is an image represented by M rows and q columns. The first images for each column of the two-dimensional second image (measurement object H) are represented as T[n], T[n+1], T[n+2], T[n+q-1]. The illumination of P[i-1] is irradiated onto the area of ​​T[j] in the scan period s(i, 1 to N), and the light amount of I_i_j is detected by the detection unit 13.

number

[0048] More precisely, when, in a scan period s(i), an area T[j] is illuminated with illumination P[i-1] and the amount of light I_i_j is measured, and an area T[j] is illuminated with illumination P'[i-1] which is the inverse of P[i-1] and the amount of light I'_i_j is measured, the image reconstruction in step S25 is performed using the following equation (2).

number

[0049] Furthermore, when the two-dimensional illumination pattern P is a random illumination pattern, the image reconstruction in step S25 is performed using the following equation (3). Here, E_i(I_i_j) is the average value of I_i_j for i. Additionally, E_i(P[i-1]) is an M row by 1 column matrix obtained by taking the average of P[i-1] for i.

number

[0050] The following steps S26 to S29 are the same as steps S15 to S18 in FIG.

[0051] <Third embodiment> 12 is a schematic diagram showing a schematic configuration of an image forming system 100 according to the third embodiment. Below, differences from the first and second embodiments will be described.

[0052] In the image forming system 100, the two-dimensional illumination pattern P is sequentially changed by the illumination projection unit 32 having a two-dimensional structure at every fixed period (scan period s), and is irradiated onto the measurement object H moving at a substantially constant speed. Then, the reflected light from the measurement object H is detected by a plurality of detection units 33, and a time-varying light receiving signal S is sent to the control unit 11. Then, based on the sequentially changed two-dimensional illumination pattern P and the one-dimensional light receiving signal S corresponding to each column (four columns in the third embodiment) of the two-dimensional illumination pattern P, the control unit 11 generates a reconstructed image (first image) that is one-dimensionally reconstructed for each column of the two-dimensional illumination pattern P at every fixed period (scan period s) using SPI technology, and generates a two-dimensional second image by arranging the first images.

[0053] The illumination projection unit 32 is, for example, a two-dimensional projector using a DMD (Digital Mirror Device). As shown in FIG. 12 , the illumination projection unit 32 sequentially changes the two-dimensional illumination pattern P shown in FIG. 9 to, for example, every four columns (e.g., {P[0], P[4], P[8], P

[12] }, {P[1], P[5], P[9], P

[13] }...{P[N-13], P[N-9], P[N-5], P[N-1]}; two-dimensional illumination pattern P) and irradiates the measurement object H with the pattern.

[0054] Multiple detection units 33 are required (at least four in the third embodiment) to detect one-dimensional light receiving signals S that vary over time corresponding to each column (four columns in the third embodiment) of the two-dimensional illumination pattern P. In order to prevent the reflected light from the measurement object H corresponding to each row of the two-dimensional illumination pattern P from interfering with each other, it is advisable to provide a space between each row of the two-dimensional illumination pattern P to be irradiated or to provide a partition between the detection units 33.

[0055] As described above, in the third embodiment, whereas in the second embodiment the illumination projection unit 22 sequentially irradiates each row of the two-dimensional illumination pattern P, the illumination projection unit 32 sequentially irradiates each multiple rows (four rows in the third embodiment).

[0056] <Fourth embodiment> 13 is a schematic diagram showing a schematic configuration of an image forming system 100 according to the fourth embodiment. Below, differences from the first to third embodiments will be described.

[0057] In the image forming system 100, a two-dimensional illumination pattern P is projected onto a measurement object H moving at a substantially uniform speed by an illumination projection unit 42 having a two-dimensional structure at regular intervals (scanning intervals s). Then, a plurality of detection units 43 detect the reflected light from the measurement object H and send a light receiving signal S to the control unit 11. Then, based on the two-dimensional illumination pattern P and the one-dimensional light receiving signal S corresponding to each column of the two-dimensional illumination pattern P (all columns in the fourth embodiment), the control unit 11 generates a reconstructed image (first image) that is one-dimensionally reconstructed for each column of the two-dimensional illumination pattern P at regular intervals (scanning intervals s) using SPI technology, and generates a two-dimensional second image by arranging the first images.

[0058] The illumination projection unit 42 is, for example, a two-dimensional projector using a DMD (Digital Mirror Device). As shown in FIG. 13 , the illumination projection unit 42 irradiates, for example, the two-dimensional illumination pattern P shown in FIG. 9 onto the measurement object H for all columns (P[0], P[1], P[2], P[N-1]; two-dimensional illumination pattern P).

[0059] The detectors 43 are provided in the same number as the columns of the two-dimensional illumination pattern P in order to detect one-dimensional light receiving signals S corresponding to each column of the two-dimensional illumination pattern P (all columns in the fourth embodiment).

[0060] As described above, in the fourth embodiment, whereas the illumination projection unit 22 in the second embodiment sequentially irradiates each row of the two-dimensional illumination pattern P, the illumination projection unit 42 irradiates each entire row, that is, irradiates all rows of the two-dimensional illumination pattern P at once.

[0061] <Other embodiments> In the above embodiments 1 to 4, the image forming system 100 is configured to not move relative to the measurement object H which moves at an approximately constant speed, but the measurement object H may also be configured to not move relative to the image forming system 100 (particularly the lighting projection unit) which moves at an approximately constant speed. 14, the one-dimensional illumination pattern P is sequentially changed at regular intervals (scanning intervals s) by the illumination projection unit 52 having a one-dimensional structure moving at a substantially constant speed, and is irradiated onto the measurement target H. The flow of the image formation process is the same as that in FIG. 15, an illumination projection unit 62 having a two-dimensional structure that moves at a substantially constant speed sequentially changes a one-dimensional illumination pattern P at regular intervals (scan period s) and irradiates the measurement target H. The flow of the image formation process is the same as that in FIG. In the image forming system 100 shown in Fig. 16, a two-dimensional illumination projection unit 72 moving at a substantially constant speed sequentially changes a two-dimensional illumination pattern P (multiple rows; for example, four rows) at regular intervals (scanning intervals s) and irradiates the measurement target H. The flow of the image forming process is the same as that in Fig. 10. 17, an illumination projection unit 82 having a two-dimensional structure that moves at a substantially constant speed irradiates a two-dimensional illumination pattern P (all rows) onto a measurement target H at a constant period (scan period s). The flow of the image formation process is the same as that in FIG. 16 and 17, a plurality of detection units 73 and 83 are required as in the third and fourth embodiments in order to detect one-dimensional light receiving signals S corresponding to each row of the two-dimensional illumination pattern P, and they need to move in the same direction and at the same speed as the illumination projection units 72 and 82, which move at a substantially constant speed. Also, in the cases of Figs. 14 and 15, the detection unit 13 may be moved.

[0062] <Effects> From the above, the image forming system 100 comprises an illumination projection unit 12 that irradiates light of multiple illumination patterns onto a measurement object moving at an approximately uniform speed, a detection unit 13 that detects the light intensity of the reflected light from the measurement object due to the light of the illumination pattern, an illumination control unit (control unit 11) that sequentially switches between illumination patterns from among the multiple illumination patterns and irradiates light from the illumination projection unit 12, and a generation unit (control unit 11) that generates a reconstructed image reconstructed two-dimensionally from the illumination patterns and the light intensity of the reflected light corresponding to the illumination pattern, making it possible to obtain one-dimensional or two-dimensional images of a moving object using a single-element detector.

[0063] Furthermore, the image forming system 100 is characterized in that the movement direction of the object to be measured is defined as a row, and the direction perpendicular to the movement direction is defined as a column, the illumination projection unit 12 irradiates light of a one-dimensional illumination pattern in the column direction, the illumination control unit (control unit 11) causes the illumination projection unit 12 to sequentially irradiate light of a plurality of one-dimensional illumination patterns, and the generation unit (control unit 11) generates a first image which is a one-dimensional reconstructed image in the column direction and generates a second image which is a two-dimensional reconstructed image based on the first image, thereby making it possible to reduce the number of illumination patterns P in each scan period s. Specifically, if the illumination pattern consists of N×N pixels, in each scan period s, when irradiating a two-dimensional illumination pattern, an N squared pattern or a 2×N squared pattern is required, whereas when irradiating a one-dimensional illumination pattern, an N pattern or a 2N pattern is sufficient.

[0064] In addition, the image forming system 100 is characterized in that the movement direction of the object to be measured is the row and the direction perpendicular to the movement direction is the column, the illumination projection unit 22 irradiates light of a two-dimensional illumination pattern, the illumination control unit (control unit 11) causes the illumination projection unit 22 to irradiate the light of the two-dimensional illumination pattern sequentially, column by column, and the generation unit (control unit 11) generates a first image which is a one-dimensional reconstructed image in the column direction and generates a second image which is a two-dimensional reconstructed image based on the first image, thereby making it possible to reduce the number of illumination patterns P in each scan period s.

[0065] In addition, in the image forming system 100, the movement direction of the object to be measured is defined as rows, and the direction perpendicular to the movement direction is defined as columns, the illumination projection unit (illumination projection unit 32 or illumination projection unit 42) has a two-dimensional structure, the illumination control unit (control unit 11) causes the illumination projection unit (illumination projection unit 32 or illumination projection unit 42) to sequentially irradiate light of a two-dimensional illumination pattern for each of multiple columns, the detection unit (detection unit 33 or detection unit 43) has a number equal to or greater than the number of the irradiated multiple columns and detects the light intensity of reflected light corresponding to each light of the columns of the illumination pattern, and the generation unit (control unit 11) generates a first image, which is a one-dimensional reconstructed image in the column direction, for each column and generates a second image, which is a two-dimensional reconstructed image, based on the first image. Therefore, in a single irradiation, the light receiving signals of each of the multiple columns are obtained at once, and the number of illumination patterns P in each scan period s can be further reduced. Specifically, when the number of columns of two-dimensional illumination patterns that are sequentially irradiated is k, the number of illumination patterns P in each scan period s can be reduced by 1 / k times compared to when irradiating a one-dimensional illumination pattern.

[0066] In addition, the image forming system 100 is equipped with an illumination projection unit 52 that moves at an approximately constant speed and irradiates the object to be measured with light of multiple illumination patterns, a detection unit 13 that detects the light intensity of the reflected light from the object to be measured due to the light of the illumination pattern, an illumination control unit (control unit 11) that sequentially switches between illumination patterns from among the multiple illumination patterns and irradiates light from the illumination projection unit 12, and a generation unit (control unit 11) that generates a reconstructed image that is reconstructed two-dimensionally from the illumination patterns and the light intensity of the reflected light corresponding to the illumination pattern, so that it is possible to obtain one-dimensional or two-dimensional images of an object while it is moving using a single-element detector.

[0067] Furthermore, the image forming system 100 is characterized in that the movement direction of the illumination projection unit 52 is defined as a row, and the direction perpendicular to the movement direction is defined as a column, the illumination projection unit 52 irradiates light of a one-dimensional illumination pattern in the column direction, the illumination control unit (control unit 11) causes the illumination projection unit 52 to sequentially irradiate light of a plurality of one-dimensional illumination patterns, and the generation unit (control unit 11) generates a first image which is a one-dimensional reconstructed image in the column direction and generates a second image which is a two-dimensional reconstructed image based on the first image, thereby making it possible to reduce the number of illumination patterns P in each scan period s.

[0068] Furthermore, the image forming system 100 is characterized in that the movement direction of the illumination projection unit 62 is defined as rows and the direction perpendicular to the movement direction is defined as columns, the illumination projection unit 62 irradiates light of a two-dimensional illumination pattern, the illumination control unit (control unit 11) causes the illumination projection unit 62 to irradiate the light of the two-dimensional illumination pattern sequentially, column by column, and the generation unit (control unit 11) generates a first image which is a one-dimensional reconstructed image in the column direction and generates a second image which is a two-dimensional reconstructed image based on the first image, thereby making it possible to reduce the number of illumination patterns P in each scan period s.

[0069] In addition, in the image forming system 100, the movement direction of the illumination projection unit (illumination projection unit 72 or illumination projection unit 82) is defined as a row, and the direction perpendicular to the movement direction is defined as a column, the illumination projection unit (illumination projection unit 72 or illumination projection unit 82) irradiates light of a two-dimensional illumination pattern, the illumination control unit (control unit 11) causes the illumination projection unit (illumination projection unit 72 or illumination projection unit 82) to irradiate the light of the two-dimensional illumination pattern sequentially for each of multiple columns, the detection unit (detection unit 73 or detection unit 83) has a number equal to or greater than the number of the irradiated multiple columns and detects the light intensity of reflected light corresponding to each light of the columns of the illumination pattern, and the generation unit (control unit 11) generates a first image, which is a one-dimensional reconstructed image in the column direction, for each column and generates a second image, which is a two-dimensional reconstructed image, based on the first image. Therefore, in a single irradiation, light receiving signals of each of multiple columns are obtained at once, and the number of illumination patterns P in each scan period s can be further reduced.

[0070] In addition, the illumination control unit (control unit 11) separately controls the detection time in the detection unit 13 and the cycle at which the image forming system 100 reads the measurement object, so that it is possible to arbitrarily slow down the moving speed of the measurement object H. In other words, by arbitrarily slowing down the moving speed of the measurement object H, it is possible to further reduce the number of irradiations of the illumination pattern P per unit time.

[0071] Moreover, the detection unit 13 is a photodiode, and is therefore inexpensive.

[0072] In addition, the lighting projection unit 12 includes a DMD, and the lighting control unit (control unit 11) corresponds an image for each bit of the RGB image to the clock frequency of the DMD and projects the image for each bit of the RGB image as an independent pattern on the lighting projection unit 12, thereby making it possible to increase the number of two-dimensional lighting patterns per unit time.

[0073] In addition, the image formation method involves sequentially switching between light from multiple illumination patterns and irradiating a measurement object moving at an approximately constant speed, detecting the light intensity of the light from the illumination pattern reflected from the measurement object, and generating a reconstructed image that is two-dimensionally reconstructed from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern. Therefore, it is possible to obtain one- or two-dimensional images of a moving object using a single-element detector.

[0074] In addition, the image formation method involves moving at a substantially constant speed, sequentially switching between light from multiple illumination patterns to irradiate the object to be measured, detecting the light intensity of the light from the illumination patterns reflected from the object to be measured, and generating a reconstructed image that is two-dimensionally reconstructed from the illumination patterns and the light intensity of the reflected light corresponding to the illumination patterns. Therefore, it is possible to obtain one- or two-dimensional images of an object while it is moving using a single-element detector.

[0075] In addition, the program causes the computer of the image forming system 100, which has an illumination projection unit 12 that irradiates light from multiple illumination patterns onto a measurement object moving at approximately a constant speed, and a detection unit 13 that detects the light intensity of the reflected light from the measurement object due to the light of the illumination pattern, to function as an illumination control unit (control unit 11) that sequentially switches between illumination patterns from among the multiple illumination patterns and irradiates light from the illumination projection unit 12, and a generation unit (control unit 11) that generates a reconstructed image reconstructed in two dimensions from the illumination patterns and the light intensity of the reflected light corresponding to the illumination pattern, thereby making it possible to obtain one-dimensional or two-dimensional images of a moving object using a single-element detector.

[0076] In addition, the program causes the computer of the image forming system 100, which has an illumination projection unit 12 that moves at an approximately constant speed and irradiates the object to be measured with light of multiple illumination patterns, and a detection unit 13 that detects the light intensity of the light of the illumination pattern reflected from the object to be measured, to function as an illumination control unit (control unit 11) that sequentially switches between illumination patterns from among the multiple illumination patterns and irradiates light from the illumination projection unit 12, and a generation unit (control unit 11) that generates a reconstructed image that is reconstructed two-dimensionally from the illumination patterns and the light intensity of the reflected light corresponding to the illumination pattern, thereby making it possible to obtain one- or two-dimensional images of an object while it is moving using a single-element detector.

[0077] The embodiment and its modified examples of the present invention have been described above, but the description of the above embodiment is merely a preferred example of the present invention, and the present invention is not limited to this. For example, an embodiment may be considered in which, at detection time t, two-dimensional illumination patterns are switched at high speed, the measurement object is irradiated with the illumination patterns, and a two-dimensional reconstructed image is obtained.

[0078] From the viewpoint of object detection, it is desirable that the base 18 of the object is made of a material that does not easily reflect the light of the projection projector. Also, light from sources other than the illumination projection unit 12, for example, indoor lighting, is reflected by the object and can reduce the S / N ratio of the analysis device, but the reconstructed image can be created in the SPI analysis while taking this effect into account.

[0079] In addition, when multiple objects are lined up at intervals on a conveyor belt, as is expected in typical production or inspection lines, by detecting the ends of each object in the direction of movement or measuring the objects at regular intervals, it is possible to reduce unnecessary measurements by not measuring the gaps between the objects.

[0080] Furthermore, in the third, fourth, seventh and eighth embodiments, a one-dimensional illumination pattern constituting a different two-dimensional illumination pattern P is irradiated for each detection unit 13, and the reflected light is detected. As a result, several times as many illumination patterns as in the second embodiment (the number of different two-dimensional illumination patterns P) are irradiated, thereby improving the image quality of the first image.

[0081] In addition, in embodiments 3, 4, 7, and 8, the N detectors may be N single detectors such as photodiodes, a combination of a line sensor and a cylindrical lens, or multiple combinations of a DMD projector and a single detector may be prepared.

[0082] Also, for example, in the above description, a hard disk or a non-volatile semiconductor memory is used as a computer-readable medium for the program according to the present invention, but the present invention is not limited to this example. As other computer-readable media, a portable recording medium such as a CD-ROM can be applied. Furthermore, a carrier wave can be applied as a medium for providing data of the program according to the present invention via a communication line.

[0083] In addition, the detailed configurations and operations of the devices constituting the image forming system may be modified as appropriate without departing from the spirit and scope of the invention. [Explanation of symbols]

[0084] 100 Image forming system 11 Control section 12 Lighting projection section 13 Detection section 14 Storage section 15 Display section 16 Control section 17 Communications Department 22 Lighting projection section 32 Lighting projection section 33 Detection unit 42 Lighting projection section 43 Detection unit 52 Lighting projection section 62 Lighting projection section 72 Lighting projection section 73 Detection unit 82 Lighting projection section 83 Detection unit

Claims

1. an illumination projection unit that irradiates light of a plurality of illumination patterns onto a measurement object moving at a substantially uniform speed; a detection unit that detects a light intensity of reflected light from the measurement object due to the light of the illumination pattern; an illumination control unit that sequentially switches the illumination pattern from among the plurality of illumination patterns and causes the illumination projection unit to emit light; a generation unit that generates a two-dimensional reconstructed image from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern; An image forming system comprising:

2. A moving direction of the measurement object is defined as a row, and a direction perpendicular to the moving direction is defined as a column, the illumination projection unit irradiates the illumination pattern in a one-dimensional manner in the column direction; the illumination control unit causes the illumination projection unit to sequentially irradiate light of the plurality of one-dimensional illumination patterns; The image forming system according to claim 1, characterized in that the generation unit generates a first image which is a one-dimensional reconstructed image in the column direction, and generates a second image which is a two-dimensional reconstructed image based on the first image.

3. A moving direction of the measurement object is defined as a row, and a direction perpendicular to the moving direction is defined as a column, the illumination projection unit emits light of the two-dimensional illumination pattern; the illumination control unit causes the illumination projection unit to sequentially irradiate the light of the two-dimensional illumination pattern line by line; The image forming system according to claim 1, characterized in that the generation unit generates a first image which is a one-dimensional reconstructed image in the column direction, and generates a second image which is a two-dimensional reconstructed image based on the first image.

4. A moving direction of the measurement object is defined as a row, and a direction perpendicular to the moving direction is defined as a column, the illumination projection unit emits light of the two-dimensional illumination pattern; the illumination control unit causes the illumination projection unit to sequentially irradiate the light of the two-dimensional illumination pattern for each of a plurality of rows; the detection unit has a number equal to or greater than the number of the plurality of rows that are irradiated, and detects a light intensity of reflected light corresponding to each of the light of the rows of the illumination pattern; The image forming system according to claim 1, characterized in that the generation unit generates a first image, which is a one-dimensional reconstructed image in the column direction, for each column, and generates a second image, which is a two-dimensional reconstructed image based on the first image.

5. an illumination projection unit that moves at a substantially uniform speed and irradiates a measurement object with light of a plurality of illumination patterns; a detection unit that detects a light intensity of reflected light from the measurement object due to the light of the illumination pattern; an illumination control unit that sequentially switches the illumination pattern from among the plurality of illumination patterns and causes the illumination projection unit to emit light; a generation unit that generates a two-dimensional reconstructed image from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern; An image forming system comprising:

6. A moving direction of the illumination projection unit is defined as a row, and a direction perpendicular to the moving direction is defined as a column, the illumination projection unit irradiates the illumination pattern in a one-dimensional manner in the column direction; the illumination control unit causes the illumination projection unit to sequentially irradiate light of the plurality of one-dimensional illumination patterns; The image forming system according to claim 5, characterized in that the generation unit generates a first image which is a one-dimensional reconstructed image in the column direction, and generates a second image which is a two-dimensional reconstructed image based on the first image.

7. A moving direction of the illumination projection unit is defined as a row, and a direction perpendicular to the moving direction is defined as a column, the illumination projection unit emits light of the two-dimensional illumination pattern; the illumination control unit causes the illumination projection unit to sequentially irradiate the light of the two-dimensional illumination pattern line by line; The image forming system according to claim 5, characterized in that the generation unit generates a first image which is a one-dimensional reconstructed image in the column direction, and generates a second image which is a two-dimensional reconstructed image based on the first image.

8. A moving direction of the illumination projection unit is defined as a row, and a direction perpendicular to the moving direction is defined as a column, the illumination projection unit emits light of the two-dimensional illumination pattern; the illumination control unit causes the illumination projection unit to sequentially irradiate the light of the two-dimensional illumination pattern for each of a plurality of rows; the detection unit has a number equal to or greater than the number of the plurality of rows that are irradiated, and detects a light intensity of reflected light corresponding to each of the light of the rows of the illumination pattern; The image forming system according to claim 5, characterized in that the generation unit generates a first image, which is a one-dimensional reconstructed image in the column direction, for each column, and generates a second image, which is a two-dimensional reconstructed image based on the first image.

9. 9. The image forming system according to claim 1, wherein the illumination control unit separately controls a detection time in the detection unit and a cycle at which the image forming system reads the object to be measured.

10. 10. The image forming system according to claim 1, wherein the detection unit is a photodiode.

11. The illumination projection unit includes a DMD. the illumination control unit corresponds an image for each bit of an RGB image to a clock frequency of the DMD; 11. The image forming system according to claim 1, wherein an image for each bit of an RGB image is projected onto the illumination projection unit as an independent pattern.

12. A plurality of illumination patterns are sequentially switched to irradiate a measurement object moving at a substantially uniform speed, Detecting the light intensity of the light of the illumination pattern reflected from the measurement object; An image forming method for generating a reconstructed image that is two-dimensionally reconstructed from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern.

13. The object is irradiated with light from multiple illumination patterns by moving at a substantially constant speed and switching between them in sequence. Detecting the light intensity of the light of the illumination pattern reflected from the measurement object; An image forming method for generating a reconstructed image that is two-dimensionally reconstructed from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern.

14. A computer of an image forming system including an illumination projection unit that irradiates light of a plurality of illumination patterns onto a measurement object moving at a substantially uniform speed, and a detection unit that detects the light intensity of the reflected light from the measurement object due to the light of the illumination patterns, an illumination control unit that sequentially switches the illumination pattern from among the plurality of illumination patterns and causes the illumination projection unit to emit light; a generation unit that generates a two-dimensional reconstructed image from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern; A program that functions as a

15. A computer of an image forming system including an illumination projection unit that moves at a substantially uniform speed and irradiates a measurement object with light of a plurality of illumination patterns, and a detection unit that detects the light intensity of reflected light from the measurement object due to the light of the illumination patterns, an illumination control unit that sequentially switches the illumination pattern from among the plurality of illumination patterns and causes the illumination projection unit to emit light; a generation unit that generates a two-dimensional reconstructed image from the illumination pattern and the light intensity of the reflected light corresponding to the illumination pattern; A program that functions as a

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